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Emergence of Long-Range Angular Correlations in Low-Multiplicity Proton-Proton Collisions. PHYSICAL REVIEW LETTERS 2024; 132:172302. [PMID: 38728735 DOI: 10.1103/physrevlett.132.172302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/22/2024] [Accepted: 03/22/2024] [Indexed: 05/12/2024]
Abstract
This Letter presents the measurement of near-side associated per-trigger yields, denoted ridge yields, from the analysis of angular correlations of charged hadrons in proton-proton collisions at sqrt[s]=13 TeV. Long-range ridge yields are extracted for pairs of charged particles with a pseudorapidity difference of 1.4<|Δη|<1.8 and a transverse momentum of 1
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2
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First Measurement of the |t| Dependence of Incoherent J/ψ Photonuclear Production. PHYSICAL REVIEW LETTERS 2024; 132:162302. [PMID: 38701458 DOI: 10.1103/physrevlett.132.162302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 11/22/2023] [Accepted: 01/23/2024] [Indexed: 05/05/2024]
Abstract
The first measurement of the cross section for incoherent photonuclear production of J/ψ vector mesons as a function of the Mandelstam |t| variable is presented. The measurement was carried out with the ALICE detector at midrapidity, |y|<0.8, using ultraperipheral collisions of Pb nuclei at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=5.02 TeV. This rapidity interval corresponds to a Bjorken-x range (0.3-1.4)×10^{-3}. Cross sections are given in five |t| intervals in the range 0.04<|t|<1 GeV^{2} and compared to the predictions by different models. Models that ignore quantum fluctuations of the gluon density in the colliding hadron predict a |t| dependence of the cross section much steeper than in data. The inclusion of such fluctuations in the same models provides a better description of the data.
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3
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Observation of Seven Astrophysical Tau Neutrino Candidates with IceCube. PHYSICAL REVIEW LETTERS 2024; 132:151001. [PMID: 38682982 DOI: 10.1103/physrevlett.132.151001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 02/15/2024] [Accepted: 02/29/2024] [Indexed: 05/01/2024]
Abstract
We report on a measurement of astrophysical tau neutrinos with 9.7 yr of IceCube data. Using convolutional neural networks trained on images derived from simulated events, seven candidate ν_{τ} events were found with visible energies ranging from roughly 20 TeV to 1 PeV and a median expected parent ν_{τ} energy of about 200 TeV. Considering backgrounds from astrophysical and atmospheric neutrinos, and muons from π^{±}/K^{±} decays in atmospheric air showers, we obtain a total estimated background of about 0.5 events, dominated by non-ν_{τ} astrophysical neutrinos. Thus, we rule out the absence of astrophysical ν_{τ} at the 5σ level. The measured astrophysical ν_{τ} flux is consistent with expectations based on previously published IceCube astrophysical neutrino flux measurements and neutrino oscillations.
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4
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ψ(2S) Suppression in Pb-Pb Collisions at the LHC. PHYSICAL REVIEW LETTERS 2024; 132:042301. [PMID: 38335364 DOI: 10.1103/physrevlett.132.042301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 05/25/2023] [Accepted: 11/20/2023] [Indexed: 02/12/2024]
Abstract
The production of the ψ(2S) charmonium state was measured with ALICE in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV, in the dimuon decay channel. A significant signal was observed for the first time at LHC energies down to zero transverse momentum, at forward rapidity (2.5
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5
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Measurements of Groomed-Jet Substructure of Charm Jets Tagged by D^{0} Mesons in Proton-Proton Collisions at sqrt[s]=13 TeV. PHYSICAL REVIEW LETTERS 2023; 131:192301. [PMID: 38000395 DOI: 10.1103/physrevlett.131.192301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 01/13/2023] [Accepted: 07/19/2023] [Indexed: 11/26/2023]
Abstract
Understanding the role of parton mass and Casimir color factors in the quantum chromodynamics parton shower represents an important step in characterizing the emission properties of heavy quarks. Recent experimental advances in jet substructure techniques have provided the opportunity to isolate and characterize gluon emissions from heavy quarks. In this Letter, the first direct experimental constraint on the charm-quark splitting function is presented, obtained via the measurement of the groomed shared momentum fraction of the first splitting in charm jets, tagged by a reconstructed D^{0} meson. The measurement is made in proton-proton collisions at sqrt[s]=13 TeV, in the low jet transverse-momentum interval of 15≤p_{T}^{jet ch}<30 GeV/c where the emission properties are sensitive to parton mass effects. In addition, the opening angle of the first perturbative emission of the charm quark, as well as the number of perturbative emissions it undergoes, is reported. Comparisons to measurements of an inclusive-jet sample show a steeper splitting function for charm quarks compared with gluons and light quarks. Charm quarks also undergo fewer perturbative emissions in the parton shower, with a reduced probability of large-angle emissions.
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Measurement of the Lifetime and Λ Separation Energy of _{Λ}^{3}H. PHYSICAL REVIEW LETTERS 2023; 131:102302. [PMID: 37739380 DOI: 10.1103/physrevlett.131.102302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 01/18/2023] [Accepted: 07/21/2023] [Indexed: 09/24/2023]
Abstract
The most precise measurements to date of the _{Λ}^{3}H lifetime τ and Λ separation energy B_{Λ} are obtained using the data sample of Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV collected by ALICE at the LHC. The _{Λ}^{3}H is reconstructed via its charged two-body mesonic decay channel (_{Λ}^{3}H→^{3}He+π^{-} and the charge-conjugate process). The measured values τ=[253±11(stat)±6(syst)] ps and B_{Λ}=[102±63(stat)±67(syst)] keV are compatible with predictions from effective field theories and confirm that the _{Λ}^{3}H structure is consistent with a weakly bound system.
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Measurement of the J/ψ Polarization with Respect to the Event Plane in Pb-Pb Collisions at the LHC. PHYSICAL REVIEW LETTERS 2023; 131:042303. [PMID: 37566833 DOI: 10.1103/physrevlett.131.042303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 02/09/2023] [Accepted: 03/28/2023] [Indexed: 08/13/2023]
Abstract
We study the polarization of inclusive J/ψ produced in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV at the LHC in the dimuon channel, via the measurement of the angular distribution of its decay products. We perform the study in the rapidity region 2.5
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First Measurement of Antideuteron Number Fluctuations at Energies Available at the Large Hadron Collider. PHYSICAL REVIEW LETTERS 2023; 131:041901. [PMID: 37566856 DOI: 10.1103/physrevlett.131.041901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/01/2022] [Accepted: 09/15/2022] [Indexed: 08/13/2023]
Abstract
The first measurement of event-by-event antideuteron number fluctuations in high energy heavy-ion collisions is presented. The measurements are carried out at midrapidity (|η|<0.8) as a function of collision centrality in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV using the ALICE detector. A significant negative correlation between the produced antiprotons and antideuterons is observed in all collision centralities. The results are compared with a state-of-the-art coalescence calculation. While it describes the ratio of higher order cumulants of the antideuteron multiplicity distribution, it fails to describe quantitatively the magnitude of the correlation between antiproton and antideuteron production. On the other hand, thermal-statistical model calculations describe all the measured observables within uncertainties only for correlation volumes that are different with respect to those describing proton yields and a similar measurement of net-proton number fluctuations.
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Enhanced Deuteron Coalescence Probability in Jets. PHYSICAL REVIEW LETTERS 2023; 131:042301. [PMID: 37566840 DOI: 10.1103/physrevlett.131.042301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 04/07/2023] [Accepted: 06/05/2023] [Indexed: 08/13/2023]
Abstract
The transverse-momentum (p_{T}) spectra and coalescence parameters B_{2} of (anti)deuterons are measured in p-p collisions at sqrt[s]=13 TeV for the first time in and out of jets. In this measurement, the direction of the leading particle with the highest p_{T} in the event (p_{T}^{lead}>5 GeV/c) is used as an approximation for the jet axis. The event is consequently divided into three azimuthal regions, and the jet signal is obtained as the difference between the toward region, that contains jet fragmentation products in addition to the underlying event (UE), and the transverse region, which is dominated by the UE. The coalescence parameter in the jet is found to be approximately a factor of 10 larger than that in the underlying event. This experimental observation is consistent with the coalescence picture and can be attributed to the smaller average phase-space distance between nucleons in the jet cone as compared with the underlying event. The results presented in this Letter are compared to predictions from a simple nucleon coalescence model, where the phase-space distributions of nucleons are generated using pythia8 with the Monash 2013 tuning, and to predictions from a deuteron production model based on ordinary nuclear reactions with parametrized energy-dependent cross sections tuned on data. The latter model is implemented in pythia8.3. Both models reproduce the observed large difference between in-jet and out-of-jet coalescence parameters, although the almost flat trend of the B_{2}^{Jet} is not reproduced by the models, which instead give a decreasing trend.
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Achieving Energy Efficiency and Impact of SAR in a WBAN Through Optimal Placement of the Relay Node. WIRELESS PERSONAL COMMUNICATIONS 2023; 130:1861-1884. [PMID: 37206635 PMCID: PMC10069738 DOI: 10.1007/s11277-023-10361-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 02/25/2023] [Indexed: 05/21/2023]
Abstract
Wireless Body Area Network (WBAN) is an emerging and promising specialized area in Wireless networks that deals with crucial health-related datasets. Unlike other wireless networks, as this type of network deals with medical facts, losing it is fatal. WBAN is a highly constrained network. Reducing energy consumption and enhancing lifetime are the two most important challenges of WBANs. One way to achieve these is by deploying relay nodes optimally in WBANs. Generally, a relay node is placed at the midpoint of the line joining the source and the destination (D) nodes. We show that such simplistic deployment of the relay nodes is not the optimal deployment, which can hamper the overall lifetime of WBANs. In this paper, we have investigated the best location to deploy a relay node on a human body. We assume that an adaptive decode and forward relay node (R) can move linearly between the source (S) and the destination (D) nodes. Moreover, the assumption is that a relay node can be deployed linearly and that the body part of a human is a flat surface and hard. We have investigated the most energy-efficient data payload size based on the optimally placed relay location. The impact of such a deployment on different system parameters, such as distance (d), payload (L), modulation scheme, specific absorption rate, and an end to end outage (O ) are examined as well. It is observed that in every aspect optimal deployment of the relay node performs an important role to enhance the lifetime of wireless body area networks. Sometimes linear relay deployment is very difficult to implement, especially on the different body parts of the human body. To address these issues, we have examined the optimal region for the relay node based on a 3D non-linear system model. The paper provides guidance for both linear and non-linear relay deployment along with the optimal data payload size under various circumstances and also considered the impact of specific absorption rates on the human body.
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Collision-System and Beam-Energy Dependence of Anisotropic Flow Fluctuations. PHYSICAL REVIEW LETTERS 2022; 129:252301. [PMID: 36608250 DOI: 10.1103/physrevlett.129.252301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 08/17/2022] [Accepted: 11/16/2022] [Indexed: 06/17/2023]
Abstract
Elliptic flow measurements from two-, four-, and six-particle correlations are used to investigate flow fluctuations in collisions of U+U at sqrt[s_{NN}]=193 GeV, Cu+Au at sqrt[s_{NN}]=200 GeV and Au+Au spanning the range sqrt[s_{NN}]=11.5-200 GeV. The measurements show a strong dependence of the flow fluctuations on collision centrality, a modest dependence on system size, and very little if any, dependence on particle species and beam energy. The results, when compared to similar LHC measurements, viscous hydrodynamic calculations, and trento model eccentricities, indicate that initial-state-driven fluctuations predominate the flow fluctuations generated in the collisions studied.
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Determinants of neointimal strut coverage in bio-degradable polymer coated ultrathin strut stent. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.1201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Introduction
Incomplete strut coverage (ISC) is the most important morphometric determinant of stent thrombosis. Determinants of ISC have been studied in thick and thin strut stents.
Purpose
To identify morphometric factors causing ISC in the biodegradable polymer-coated ultra-thin strut drug eluting stent (BP-UTS-DES) that are designed to encourage better strut coverage.
Methods
Patients undergoing implantation of a 65μm BP-UTS-DES had opportunistic OCT during staged PCI to assess strut coverage at 90 days. Images were analysed offline by experienced operators blinded to patient and procedural data. Neointimal thickness (NIT, μm) was measured as the minimum endoluminal distant between the strut and lumen border. All malapposed struts were considered uncovered. ISC was defined as <100% covered struts in a frame. Stepwise logistic regression using multiple morphometric variables was used to identify independent determinants of ISC including markers of circumferential distribution of neointimal growth (CVS,NUS,RUS), symmetry of stent expansion (SEI, AVS, MAS) in each cross section and the geographical location of the frame along the axis of the stent.
Results
We analysed 11652 frames of 65 stents (1976 mm) in 46 arteries of 40 patients. All stents were post dilated. 95.6% arteries had >20mm stents, 39.1% were overlapped and 15.2% were chronic total occlusions. Malapposition was seen in 2.6% of all struts and 39.2% of uncovered struts. The proportion of covered struts decreased as indices of circumferential uniformity of distribution of neointimal hyperplasia increased (CVS: r=0.37, p<0.001; RUS: r=0.36, p<0.001; NUS: r=0.52, p<0.001). As uniformity of stent expansion improved (SEI increased) strut coverage and circumferential uniformity of neointimal hyperplasia increased (CVS, NUS and RUS decreased) suggesting that distribution of neointimal growth becomes homogeneous as uniformity of stent expansion improves (Fig. 1). Determinants ISC is shown in Table 1.
Conclusion
SEI but not AVS or MAS determines ISC. Compared to the distal third of the stent frames in the middle third had lower and the proximal third had high risk of ISC.
Funding Acknowledgement
Type of funding sources: None.
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First study of the two-body scattering involving charm hadrons. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.052010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Evidence for Nonlinear Gluon Effects in QCD and Their Mass Number Dependence at STAR. PHYSICAL REVIEW LETTERS 2022; 129:092501. [PMID: 36083674 DOI: 10.1103/physrevlett.129.092501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 07/12/2022] [Accepted: 07/29/2022] [Indexed: 06/15/2023]
Abstract
The STAR Collaboration reports measurements of back-to-back azimuthal correlations of di-π^{0}s produced at forward pseudorapidities (2.6<η<4.0) in p+p, p+Al, and p+Au collisions at a center-of-mass energy of 200 GeV. We observe a clear suppression of the correlated yields of back-to-back π^{0} pairs in p+Al and p+Au collisions compared to the p+p data. The observed suppression of back-to-back pairs as a function of transverse momentum suggests nonlinear gluon dynamics arising at high parton densities. The larger suppression found in p+Au relative to p+Al collisions exhibits a dependence of the saturation scale Q_{s}^{2} on the mass number A. A linear scaling of the suppression with A^{1/3} is observed with a slope of -0.09±0.01.
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Fermi surface of the chiral topological semimetal PtGa. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:425502. [PMID: 35940168 DOI: 10.1088/1361-648x/ac87e5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
PtGa is a topological semimetal with giant spin-split Fermi arcs. Here, we report on angular-dependent de Haas-van Alphen (dHvA) measurements combined with band-structure calculations to elucidate the details of the bulk Fermi surface of PtGa. The strong spin-orbit coupling leads to eight bands crossing the Fermi energy that form a multitude of Fermi surfaces with closed extremal orbits and results in very rich dHvA spectra. The large number of experimentally observed dHvA frequencies make the assignment to the equally large number of calculated dHvA orbits challenging. Nevertheless, we find consistency between experiment and calculations verifying the topological character with maximal Chern number of the spin-split Fermi surface.
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Abstract
Particle accelerators and storage rings have been transformative instruments of discovery, and, for many applications, innovations in particle-beam cooling have been a principal driver of that success1. Stochastic cooling (SC), one of the most important conceptual and technological advances in this area2–6, cools a beam through granular sampling and correction of its phase-space structure, thus bearing resemblance to a ‘Maxwell’s demon’. The extension of SC from the microwave regime up to optical frequencies and bandwidths has long been pursued, as it could increase the achievable cooling rates by three to four orders of magnitude and provide a powerful tool for future accelerators. First proposed nearly 30 years ago, optical stochastic cooling (OSC) replaces the conventional microwave elements of SC with optical-frequency analogues and is, in principle, compatible with any species of charged-particle beam7,8. Here we describe a demonstration of OSC in a proof-of-principle experiment at the Fermi National Accelerator Laboratory’s Integrable Optics Test Accelerator9,10. The experiment used 100-MeV electrons and a non-amplified configuration of OSC with a radiation wavelength of 950 nm, and achieved strong, simultaneous cooling of the beam in all degrees of freedom. This realization of SC at optical frequencies serves as a foundation for more advanced experiments with high-gain optical amplification, and advances opportunities for future operational OSC systems with potential benefit to a broad user community in the accelerator-based sciences. Stochastic cooling at optical frequencies is demonstrated in an experiment at the Fermi National Accelerator Laboratory’s Integrable Optics Test Accelerator, substantially increasing the bandwidth of stochastic cooling compared with conventional systems.
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Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2022; 82:618. [PMID: 35859696 PMCID: PMC9288420 DOI: 10.1140/epjc/s10052-022-10549-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 06/24/2022] [Indexed: 06/15/2023]
Abstract
DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6 × 6 × 6 m 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.
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Hypertriton Production in p-Pb Collisions at sqrt[s_{NN}]=5.02 TeV. PHYSICAL REVIEW LETTERS 2022; 128:252003. [PMID: 35802430 DOI: 10.1103/physrevlett.128.252003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 01/28/2022] [Accepted: 06/03/2022] [Indexed: 06/15/2023]
Abstract
The study of nuclei and antinuclei production has proven to be a powerful tool to investigate the formation mechanism of loosely bound states in high-energy hadronic collisions. The first measurement of the production of _{Λ}^{3}H in p-Pb collisions at sqrt[s_{NN}]=5.02 TeV is presented in this Letter. Its production yield measured in the rapidity interval -1<y<0 for the 40% highest-multiplicity p-Pb collisions is dN/dy=[6.3±1.8(stat)±1.2(syst)]×10^{-7}. The measurement is compared with the expectations of statistical hadronization and coalescence models, which describe the nucleosynthesis in hadronic collisions. These two models predict very different yields of the hypertriton in charged particle multiplicity environments relevant to small collision systems such as p-Pb, and therefore the measurement of dN/dy is crucial to distinguish between them. The precision of this measurement leads to the exclusion with a significance larger than 6.9σ of some configurations of the statistical hadronization model, thus constraining the theory behind the production of loosely bound states at hadron colliders.
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Measurements of Proton High-Order Cumulants in sqrt[s_{NN}]=3 GeV Au+Au Collisions and Implications for the QCD Critical Point. PHYSICAL REVIEW LETTERS 2022; 128:202303. [PMID: 35657878 DOI: 10.1103/physrevlett.128.202303] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 04/11/2022] [Indexed: 06/15/2023]
Abstract
We report cumulants of the proton multiplicity distribution from dedicated fixed-target Au+Au collisions at sqrt[s_{NN}]=3.0 GeV, measured by the STAR experiment in the kinematic acceptance of rapidity (y) and transverse momentum (p_{T}) within -0.5<y<0 and 0.4<p_{T}<2.0 GeV/c. In the most central 0%-5% collisions, a proton cumulant ratio is measured to be C_{4}/C_{2}=-0.85±0.09 (stat)±0.82 (syst), which is 2σ below the Poisson baseline with respect to both the statistical and systematic uncertainties. The hadronic transport UrQMD model reproduces our C_{4}/C_{2} in the measured acceptance. Compared to higher energy results and the transport model calculations, the suppression in C_{4}/C_{2} is consistent with fluctuations driven by baryon number conservation and indicates an energy regime dominated by hadronic interactions. These data imply that the QCD critical region, if created in heavy-ion collisions, could only exist at energies higher than 3 GeV.
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Measurements of _{Λ}^{3}H and _{Λ}^{4}H Lifetimes and Yields in Au+Au Collisions in the High Baryon Density Region. PHYSICAL REVIEW LETTERS 2022; 128:202301. [PMID: 35657899 DOI: 10.1103/physrevlett.128.202301] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 01/26/2022] [Accepted: 04/05/2022] [Indexed: 06/15/2023]
Abstract
We report precision measurements of hypernuclei _{Λ}^{3}H and _{Λ}^{4}H lifetimes obtained from Au+Au collisions at sqrt[s_{NN}]=3.0 GeV and 7.2 GeV collected by the STAR experiment at the Relativistic Heavy Ion Collider, and the first measurement of _{Λ}^{3}H and _{Λ}^{4}H midrapidity yields in Au+Au collisions at sqrt[s_{NN}]=3.0 GeV. _{Λ}^{3}H and _{Λ}^{4}H, being the two simplest bound states composed of hyperons and nucleons, are cornerstones in the field of hypernuclear physics. Their lifetimes are measured to be 221±15(stat)±19(syst) ps for _{Λ}^{3}H and 218±6(stat)±13(syst) ps for _{Λ}^{4}H. The p_{T}-integrated yields of _{Λ}^{3}H and _{Λ}^{4}H are presented in different centrality and rapidity intervals. It is observed that the shape of the rapidity distribution of _{Λ}^{4}H is different for 0%-10% and 10%-50% centrality collisions. Thermal model calculations, using the canonical ensemble for strangeness, describes the _{Λ}^{3}H yield well, while underestimating the _{Λ}^{4}H yield. Transport models, combining baryonic mean-field and coalescence (jam) or utilizing dynamical cluster formation via baryonic interactions (phqmd) for light nuclei and hypernuclei production, approximately describe the measured _{Λ}^{3}H and _{Λ}^{4}H yields. Our measurements provide means to precisely assess our understanding of the fundamental baryonic interactions with strange quarks, which can impact our understanding of more complicated systems involving hyperons, such as the interior of neutron stars or exotic hypernuclei.
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Post-load glucose spike: a better predictor of post-MI prognosis than post-load glucose in patients without known diabetes. Eur J Prev Cardiol 2022. [DOI: 10.1093/eurjpc/zwac056.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: None.
Background
In non-diabetic population, number of deaths increase as the post-challenge glucose spike (PGS) i.e. difference between the fasting and 2h-PG increases in the DECODE study.
Purpose
To assess whether PGS is a better predictor of post-ACS prognosis in patients without known diabetes.
Methods
Retrospective cohort analysis of post-MI survivors (n=1056) without known diabetes undergoing pre-discharge oral glucose tolerance test. A standardised dataset was collected for the Myocardial Infarction National Audit Project. MACE (death or non-fatal re-infarction) over 5 (median 3.4) years was collected from notes review. Predictors of MACE were determined from Cox proportional hazard regression (stepwise) models adjusted for several variables (tested for collinearity) including GRACE score (GRS), fasting (FG) and 2-hour post-load glucose (2hG) and PGS as % of the 2hG (%PGS) (VIF=3.12). Incremental predictive value of PGS over 2hG was tested using probabilities of MACE calculated from logistic regression models using the same covariates and FG, 2hG and PGS individually and in combination applying c-statistics, continuous net reclassification improvement (cNRI) and integrated discrimination improvement (IDI).
Results
Of the patients 469 (44.4%) had normal glucose tolerance, 378(35.8%) preDM and 209 (19.8%) had new DM. In the whole cohort, MACE was predicted by %PGS (HR 1.02 (1.01-1.03), p<0.0001), GRS (HR 1.01, (1.01-1.02), p<0.0001), discharge with betablockers (HR 1.50 (1.14-1.98), p=0.0037), previous history of MI (HR 1.44 (1.02-2.03), p=0.039) but neither FG nor 2hG were included in the final model. MACE was predicted by %PGS (HR 1.04 (1.02-1.06), p<0.0001) in the non-diabetic group but not in the new DM patients (HR 1.02 (0.99-1.05), p=0.296). Addition of PGS to models containing FG and 2hG improved reclassification by 22.6% for events and 5.0% for non-events (NRI>0 0.275, p<0.001) and discrimination (IDI 0.0076, p=0.033). However the c-statistics did not change significantly (ΔAUC 0.0094, p=0.099).
Conclusion
PGS is a better predictor of post-MI prognosis than FG or 2hG in patients without known diabetes.
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Does pre-diabetes predict the extent of coronary artery disease? Eur J Prev Cardiol 2022. [DOI: 10.1093/eurjpc/zwac056.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: None.
Background
Extensive coronary artery disease (CAD) is common in diabetes mellitus. This relation between the extent of CAD and prediabetes (pDM)is less well established.
Purpose
To explore whether non-diabetic hyperglycaemia, assessed by HbA1c, is associated with extent of angiographic CAD, independent of traditional cardiovascular risk factors.
Methods
Retrospective cohort analysis of consecutive patients, without known DM undergoing coronary angiography for stable angina, who were screened for hyperglycaemia over 18 months. HbA1c was measured; pre-diabetes was defined as HbA1c 5.7-6.4%.Extent of CAD was assessed using the SYNTAX score. Presence of CAD was defined as visually estimated ≥50% luminal obstruction in arteries ≥1.5 mm diameter. Age, BMI, risk factors for CAD, HbA1c, total and LDL-cholesterol were recorded. The pre-diabetes and normal groups were compared using Mann-Whitney test for continuous variables and chi-squared test for categorical variables. Multiple logistic and linear regressions were used to assess the effect variables on SYNTAX score. Spearman rank correlation was used to assess the relation between HbA1c and SYNTAX score.
Results
1071 patients had angiograms done. 207 had DM, 19 had new diagnosis of DM and 181 missed the screening leaving 664 who had HbA1c measured. 51 poor quality angiograms were excluded from SYNTAX calculation. Data was analysed for 613 (306 normal, 307 pDM) patients. The patients with prediabetes were older, had higher prevalence of risk factors, BMI, fasting glucose and SYNTAX score. HbA1c (OR 2.07, 95% CI 1.32 to 3.25, p=0.002) and the presence of pDM (OR 1.89, 95% CI 1.32 to 2.69, p<0.001) independently predicted the presence of CAD. HbA1c (Coefficient 2.42, SE 1.09, p=0.027) and the presence of pDM (Coefficient 2.25, SE 0.92, p=0.015) independently predicted the SYNTAX score. The correlation between HbA1c and SYNTAX score was weak but significant (Spearman's coefficient 0.206, 95% CI 0.129 to 0.281, p<0.0001).
Conclusion
HbA1c predicts the extent of CAD as measured by SYNTAX score in patients without known diabetes. Presence of pre-diabetes is an independent predictor of extent of CAD.
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Polarization of Λ and Λ[over ¯] Hyperons along the Beam Direction in Pb-Pb Collisions at sqrt[s]_{NN}=5.02 TeV. PHYSICAL REVIEW LETTERS 2022; 128:172005. [PMID: 35570422 DOI: 10.1103/physrevlett.128.172005] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 01/04/2022] [Accepted: 03/16/2022] [Indexed: 06/15/2023]
Abstract
The polarization of the Λ and Λ[over ¯] hyperons along the beam (z) direction, P_{z}, has been measured in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV recorded with ALICE at the Large Hadron Collider (LHC). The main contribution to P_{z} comes from elliptic flow-induced vorticity and can be characterized by the second Fourier sine coefficient P_{z,s2}=⟨P_{z}sin(2φ-2Ψ_{2})⟩, where φ is the hyperon azimuthal emission angle and Ψ_{2} is the elliptic flow plane angle. We report the measurement of P_{z,s2} for different collision centralities and in the 30%-50% centrality interval as a function of the hyperon transverse momentum and rapidity. The P_{z,s2} is positive similarly as measured by the STAR Collaboration in Au-Au collisions at sqrt[s_{NN}]=200 GeV, with somewhat smaller amplitude in the semicentral collisions. This is the first experimental evidence of a nonzero hyperon P_{z} in Pb-Pb collisions at the LHC. The comparison of the measured P_{z,s2} with the hydrodynamic model calculations shows sensitivity to the competing contributions from thermal and the recently found shear-induced vorticity, as well as to whether the polarization is acquired at the quark-gluon plasma or the hadronic phase.
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Probing the Gluonic Structure of the Deuteron with J/ψ Photoproduction in d+Au Ultraperipheral Collisions. PHYSICAL REVIEW LETTERS 2022; 128:122303. [PMID: 35394314 DOI: 10.1103/physrevlett.128.122303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/18/2022] [Accepted: 02/25/2022] [Indexed: 06/14/2023]
Abstract
Understanding gluon density distributions and how they are modified in nuclei are among the most important goals in nuclear physics. In recent years, diffractive vector meson production measured in ultraperipheral collisions (UPCs) at heavy-ion colliders has provided a new tool for probing the gluon density. In this Letter, we report the first measurement of J/ψ photoproduction off the deuteron in UPCs at the center-of-mass energy sqrt[s_{NN}]=200 GeV in d+Au collisions. The differential cross section as a function of momentum transfer -t is measured. In addition, data with a neutron tagged in the deuteron-going zero-degree calorimeter is investigated for the first time, which is found to be consistent with the expectation of incoherent diffractive scattering at low momentum transfer. Theoretical predictions based on the color glass condensate saturation model and the leading twist approximation nuclear shadowing model are compared with the data quantitatively. A better agreement with the saturation model has been observed. With the current measurement, the results are found to be directly sensitive to the gluon density distribution of the deuteron and the deuteron breakup process, which provides insights into the nuclear gluonic structure.
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Measurement of the Groomed Jet Radius and Momentum Splitting Fraction in pp and Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV. PHYSICAL REVIEW LETTERS 2022; 128:102001. [PMID: 35333086 DOI: 10.1103/physrevlett.128.102001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 11/29/2021] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
This article presents groomed jet substructure measurements in pp and Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV with the ALICE detector. The soft drop grooming algorithm provides access to the hard parton splittings inside a jet by removing soft wide-angle radiation. We report the groomed jet momentum splitting fraction, z_{g}, and the (scaled) groomed jet radius, θ_{g}. Charged-particle jets are reconstructed at midrapidity using the anti-k_{T} algorithm with resolution parameters R=0.2 and R=0.4. In heavy-ion collisions, the large underlying event poses a challenge for the reconstruction of groomed jet observables, since fluctuations in the background can cause groomed parton splittings to be misidentified. By using strong grooming conditions to reduce this background, we report these observables fully corrected for detector effects and background fluctuations for the first time. A narrowing of the θ_{g} distribution in Pb-Pb collisions compared to pp collisions is seen, which provides direct evidence of the modification of the angular structure of jets in the quark-gluon plasma. No significant modification of the z_{g} distribution in Pb-Pb collisions compared to pp collisions is observed. These results are compared with a variety of theoretical models of jet quenching, and provide constraints on jet energy-loss mechanisms and coherence effects in the quark-gluon plasma.
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Search for the Chiral Magnetic Effect via Charge-Dependent Azimuthal Correlations Relative to Spectator and Participant Planes in Au+Au Collisions at sqrt[s_{NN}]=200 GeV. PHYSICAL REVIEW LETTERS 2022; 128:092301. [PMID: 35302834 DOI: 10.1103/physrevlett.128.092301] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 10/11/2021] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
The chiral magnetic effect (CME) refers to charge separation along a strong magnetic field due to imbalanced chirality of quarks in local parity and charge-parity violating domains in quantum chromodynamics. The experimental measurement of the charge separation is made difficult by the presence of a major background from elliptic azimuthal anisotropy. This background and the CME signal have different sensitivities to the spectator and participant planes, and could thus be determined by measurements with respect to these planes. We report such measurements in Au+Au collisions at a nucleon-nucleon center-of-mass energy of 200 GeV at the Relativistic Heavy-Ion Collider. It is found that the charge separation, with the flow background removed, is consistent with zero in peripheral (large impact parameter) collisions. Some indication of finite CME signals is seen in midcentral (intermediate impact parameter) collisions. Significant residual background effects may, however, still be present.
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Is there a unique cardiac deformation behaviour in COVID-patients? The SARS-2-DEFORM Study. Eur Heart J Cardiovasc Imaging 2022. [DOI: 10.1093/ehjci/jeab289.426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: None.
OnBehalf
SARS-2-DEFORM
Myocardial dysfunction is common and associated with worse outcomes in patients with ARDS, pulmonary embolism or severe sepsis due to pulmonary hypoxic vasoconstriction. Thrombotic events, myocarditis and endothelial dysfunction may contribute to these effects in COVID-19 infection. The evaluation of myocardial function can provide prognostic information regarding the severity of a current COVID-19 infection, but scarce data available on the role of Deformation Indices obtained by Speckle Tracking Analysis to describe unique features of myocardial dysfunction in COVID-19 pneumonitis. AIMS: to evaluate the value of ventricular and atrial Deformation Imaging in patients with COVID-19 infection and hypoxia who had preserved systolic function in comparison with age-, gender-, BSA, hypoxia-matched control subjects with respiratory disease on oxygen therapy, thus excluding the effects of pulmonary vasoconstriction. We also assessed the impact of biochemical and inflammatory markers on the Echo-Indices. METHODS: 21 patients with PCR-confirmed COVID-pneumonitis (15 males, age:60.1 ± 16.1yrs, range:43-89) and 31 control, PCR-negative subjects (age:62.8 ± 15.5yrs, range:22-92) on oxygen with matched biometric data were compared. 2 examiners, blinded to the clinical data performed off-line standard Echocardiographic assessment and Deformation Imaging by 2D-Speckle Tracking Analysis with the TomTec Arena software package (Unterschleissheim, Germany) in both ventricles and atria. Plasma chemistry data were compared between the groups. RESULTS: No differences found in the biometric data and the cardiac chamber sizes between the groups. The global systolic strain indices were reduced in the COVID-group in the LV, but not the EF (LV-GLS -13.6 ± 2.9 vs -16 ± 1.1%, LV-GCS -24.8 ± 2.4 vs -28.9 ± 2.8%, p = 0.001, LVEF 61 ± 3.7 vs 60.7 ± 4.9%, p = NS), and these were reduced in the RV and RA, but not the TAPSE and TDI-S` when compared to the controls (RV-FWS -12.3 ± 2.9 vs -16.2 ± 1.5%, RV-GLS -14.6 ± 3.4 vs -17.1 ± 1.7%, RASr 18.5 ± 6 vs 22.3 ± 4.8% p = 0.005. Interestingly, the dispersion of contraction was increased in the COVID-patients in both the LV (LV-SD 416.2 ± 81.8 vs 309.8 ± 69.8ms, p < 0.001) and the RV and the RA (RV-SD 414.9 ± 117 vs 303.8 ± 61ms, RA-SD 33.5 ± 6.7 vs 26.1 ± 4.7ms, p < 0.001). The right heart indices correlated well with the biochemical data (RV-FWS and RV-SD with Ferritin r = 0.54 and -0.46, p = 0.003, RASr with GLS r = 0.64, p = 0.002, RA-SD with Troponin, p = 0.01 and with the RV-coupling Index r = 0.72, p = 0.02). CONCLUSIONS: Myocardial dysfunction is common among severely ill and hypoxic COVID-19 patients. The conventional Echo-parameters of systolic function or pulmonary pressures do not appear being specific but the Deformation Indices can provide tools to detect unique changes of the myocardial function and dys-synchrony imposed by the COVID-19 infection, independently from the impact of hypoxia or raised pulmonary pressures, hence they can predict outcome more accurately.
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Measurement of Prompt D^{0}, Λ_{c}^{+}, and Σ_{c}^{0,++}(2455) Production in Proton-Proton Collisions at sqrt[s]=13 TeV. PHYSICAL REVIEW LETTERS 2022; 128:012001. [PMID: 35061479 DOI: 10.1103/physrevlett.128.012001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 11/09/2021] [Accepted: 11/24/2021] [Indexed: 06/14/2023]
Abstract
The p_{T}-differential production cross sections of prompt D^{0}, Λ_{c}^{+}, and Σ_{c}^{0,++}(2455) charmed hadrons are measured at midrapidity (|y|<0.5) in pp collisions at sqrt[s]=13 TeV. This is the first measurement of Σ_{c}^{0,++} production in hadronic collisions. Assuming the same production yield for the three Σ_{c}^{0,+,++} isospin states, the baryon-to-meson cross section ratios Σ_{c}^{0,+,++}/D^{0} and Λ_{c}^{+}/D^{0} are calculated in the transverse momentum (p_{T}) intervals 2<p_{T}<12 and 1<p_{T}<24 GeV/c. Values significantly larger than in e^{+}e^{-} collisions are observed, indicating for the first time that baryon enhancement in hadronic collisions also extends to the Σ_{c}. The feed-down contribution to Λ_{c}^{+} production from Σ_{c}^{0,+,++} is also reported and is found to be larger than in e^{+}e^{-} collisions. The data are compared with predictions from event generators and other phenomenological models, providing a sensitive test of the different charm-hadronization mechanisms implemented in the models.
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Measurement of the Cross Sections of Ξ_{c}^{0} and Ξ_{c}^{+} Baryons and of the Branching-Fraction Ratio BR(Ξ_{c}^{0}→Ξ^{-}e^{+}ν_{e})/BR(Ξ_{c}^{0}→Ξ^{-}π^{+}) in pp Collisions at sqrt[s]=13 TeV. PHYSICAL REVIEW LETTERS 2021; 127:272001. [PMID: 35061415 DOI: 10.1103/physrevlett.127.272001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/18/2021] [Accepted: 11/19/2021] [Indexed: 06/14/2023]
Abstract
The p_{T}-differential cross sections of prompt charm-strange baryons Ξ_{c}^{0} and Ξ_{c}^{+} were measured at midrapidity (|y|<0.5) in proton-proton (pp) collisions at a center-of-mass energy sqrt[s]=13 TeV with the ALICE detector at the LHC. The Ξ_{c}^{0} baryon was reconstructed via both the semileptonic decay (Ξ^{-}e^{+}ν_{e}) and the hadronic decay (Ξ^{-}π^{+}) channels. The Ξ_{c}^{+} baryon was reconstructed via the hadronic decay (Ξ^{-}π^{+}π^{+}) channel. The branching-fraction ratio BR(Ξ_{c}^{0}→Ξ^{-}e^{+}ν_{e})/BR(Ξ_{c}^{0}→Ξ^{-}π^{+})=1.38±0.14(stat)±0.22(syst) was measured with a total uncertainty reduced by a factor of about 3 with respect to the current world average reported by the Particle Data Group. The transverse momentum (p_{T}) dependence of the Ξ_{c}^{0}- and Ξ_{c}^{+}-baryon production relative to the D^{0} meson and to the Σ_{c}^{0,+,++}- and Λ_{c}^{+}-baryon production are reported. The baryon-to-meson ratio increases toward low p_{T} up to a value of approximately 0.3. The measurements are compared with various models that take different hadronization mechanisms into consideration. The results provide stringent constraints to these theoretical calculations and additional evidence that different processes are involved in charm hadronization in electron-positron (e^{+}e^{-}) and hadronic collisions.
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Measurement of the Sixth-Order Cumulant of Net-Proton Multiplicity Distributions in Au+Au Collisions at sqrt[s_{NN}]=27, 54.4, and 200 GeV at RHIC. PHYSICAL REVIEW LETTERS 2021; 127:262301. [PMID: 35029466 DOI: 10.1103/physrevlett.127.262301] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 08/19/2021] [Accepted: 11/11/2021] [Indexed: 06/14/2023]
Abstract
According to first-principle lattice QCD calculations, the transition from quark-gluon plasma to hadronic matter is a smooth crossover in the region μ_{B}≤T_{c}. In this range the ratio, C_{6}/C_{2}, of net-baryon distributions are predicted to be negative. In this Letter, we report the first measurement of the midrapidity net-proton C_{6}/C_{2} from 27, 54.4, and 200 GeV Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC). The dependence on collision centrality and kinematic acceptance in (p_{T}, y) are analyzed. While for 27 and 54.4 GeV collisions the C_{6}/C_{2} values are close to zero within uncertainties, it is observed that for 200 GeV collisions, the C_{6}/C_{2} ratio becomes progressively negative from peripheral to central collisions. Transport model calculations without critical dynamics predict mostly positive values except for the most central collisions within uncertainties. These observations seem to favor a smooth crossover in the high-energy nuclear collisions at top RHIC energy.
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Λ_{c}^{+} Production and Baryon-to-Meson Ratios in pp and p-Pb Collisions at sqrt[s_{NN}]=5.02 TeV at the LHC. PHYSICAL REVIEW LETTERS 2021; 127:202301. [PMID: 34860039 DOI: 10.1103/physrevlett.127.202301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 05/27/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
The prompt production of the charm baryon Λ_{c}^{+} and the Λ_{c}^{+}/D^{0} production ratios were measured at midrapidity with the ALICE detector in pp and p-Pb collisions at sqrt[s_{NN}]=5.02 TeV. These new measurements show a clear decrease of the Λ_{c}^{+}/D^{0} ratio with increasing transverse momentum (p_{T}) in both collision systems in the range 2<p_{T}<12 GeV/c, exhibiting similarities with the light-flavor baryon-to-meson ratios p/π and Λ/K_{S}^{0}. At low p_{T}, predictions that include additional color-reconnection mechanisms beyond the leading-color approximation, assume the existence of additional higher-mass charm-baryon states, or include hadronization via coalescence can describe the data, while predictions driven by charm-quark fragmentation processes measured in e^{+}e^{-} and e^{-}p collisions significantly underestimate the data. The results presented in this Letter provide significant evidence that the established assumption of universality (colliding-system independence) of parton-to-hadron fragmentation is not sufficient to describe charm-baryon production in hadronic collisions at LHC energies.
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Experimental Evidence for an Attractive p-ϕ Interaction. PHYSICAL REVIEW LETTERS 2021; 127:172301. [PMID: 34739260 DOI: 10.1103/physrevlett.127.172301] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/08/2021] [Accepted: 09/14/2021] [Indexed: 06/13/2023]
Abstract
This Letter presents the first experimental evidence of the attractive strong interaction between a proton and a ϕ meson. The result is obtained from two-particle correlations of combined p-ϕ⊕ p[over ¯]-ϕ pairs measured in high-multiplicity pp collisions at sqrt[s]=13 TeV by the ALICE Collaboration. The spin-averaged scattering length and effective range of the p-ϕ interaction are extracted from the fully corrected correlation function employing the Lednický-Lyuboshits approach. In particular, the imaginary part of the scattering length vanishes within uncertainties, indicating that inelastic processes do not play a prominent role for the p-ϕ interaction. These data demonstrate that the interaction is dominated by elastic p-ϕ scattering. Furthermore, an analysis employing phenomenological Gaussian- and Yukawa-type potentials is conducted. Under the assumption of the latter, the N-ϕ coupling constant is found to be g_{N-ϕ}=0.14±0.03(stat)±0.02(syst). This work provides valuable experimental input to accomplish a self-consistent description of the N-ϕ interaction, which is particularly relevant for the more fundamental studies on partial restoration of chiral symmetry in nuclear medium.
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Multiharmonic Correlations of Different Flow Amplitudes in Pb-Pb Collisions at sqrt[s_{NN}]=2.76 TeV. PHYSICAL REVIEW LETTERS 2021; 127:092302. [PMID: 34506195 DOI: 10.1103/physrevlett.127.092302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 06/09/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
The event-by-event correlations between three flow amplitudes are measured for the first time in Pb-Pb collisions, using higher-order symmetric cumulants. We find that different three-harmonic correlations develop during the collective evolution of the medium when compared to correlations that exist in the initial state. These new results cannot be interpreted in terms of previous lower-order flow measurements since contributions from two-harmonic correlations are explicitly removed in the new observables. A comparison to Monte Carlo simulations provides new and independent constraints for the initial conditions and system properties of nuclear matter created in heavy-ion collisions.
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Erratum: Azimuthal Anisotropy of K_{S}^{0} and Λ+Λ[over ¯] Production at Midrapidity from Au+Au Collisions at sqrt[s]_{NN}=130 GeV [Phys. Rev. Lett. 89, 132301 (2002)]. PHYSICAL REVIEW LETTERS 2021; 127:089901. [PMID: 34477449 DOI: 10.1103/physrevlett.127.089901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Indexed: 06/13/2023]
Abstract
This corrects the article DOI: 10.1103/PhysRevLett.89.132301.
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Erratum: Azimuthal Anisotropy at the Relativistic Heavy Ion Collider: The First and Fourth Harmonics [Phys. Rev. Lett. 92, 062301 (2004)]. PHYSICAL REVIEW LETTERS 2021; 127:069901. [PMID: 34420354 DOI: 10.1103/physrevlett.127.069901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Indexed: 06/13/2023]
Abstract
This corrects the article DOI: 10.1103/PhysRevLett.92.062301.
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Soft-Dielectron Excess in Proton-Proton Collisions at sqrt[s]=13 TeV. PHYSICAL REVIEW LETTERS 2021; 127:042302. [PMID: 34355943 DOI: 10.1103/physrevlett.127.042302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 04/12/2021] [Accepted: 06/08/2021] [Indexed: 06/13/2023]
Abstract
A measurement of dielectron production in proton-proton (pp) collisions at sqrt[s]=13 TeV, recorded with the ALICE detector at the CERN LHC, is presented in this Letter. The data set was recorded with a reduced magnetic solenoid field. This enables the investigation of a kinematic domain at low dielectron (ee) invariant mass m_{ee} and pair transverse momentum p_{T,ee} that was previously inaccessible at the LHC. The cross section for dielectron production is studied as a function of m_{ee}, p_{T,ee}, and event multiplicity dN_{ch}/dη. The expected dielectron rate from hadron decays, called hadronic cocktail, utilizes a parametrization of the measured η/π^{0} ratio in pp and proton-nucleus collisions, assuming that this ratio shows no strong dependence on collision energy at low transverse momentum. Comparison of the measured dielectron yield to the hadronic cocktail at 0.15<m_{ee}<0.6 GeV/c^{2} and for p_{T,ee}<0.4 GeV/c indicates an enhancement of soft dielectrons, reminiscent of the "anomalous" soft-photon and soft-dilepton excess in hadron-hadron collisions reported by several experiments under different experimental conditions. The enhancement factor over the hadronic cocktail amounts to 1.61±0.13(stat)±0.17(syst,data)±0.34(syst,cocktail) in the ALICE acceptance. Acceptance-corrected excess spectra in m_{ee} and p_{T,ee} are extracted and compared with calculations of dielectron production from hadronic bremsstrahlung and thermal radiation within a hadronic many-body approach.
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Elliptic Flow of Electrons from Beauty-Hadron Decays in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV. PHYSICAL REVIEW LETTERS 2021; 126:162001. [PMID: 33961482 DOI: 10.1103/physrevlett.126.162001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 01/27/2021] [Accepted: 03/09/2021] [Indexed: 06/12/2023]
Abstract
The elliptic flow of electrons from beauty hadron decays at midrapidity (|y|<0.8) is measured in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV with the ALICE detector at the LHC. The azimuthal distribution of the particles produced in the collisions can be parametrized with a Fourier expansion, in which the second harmonic coefficient represents the elliptic flow, v_{2}. The v_{2} coefficient of electrons from beauty hadron decays is measured for the first time in the transverse momentum (p_{T}) range 1.3-6 GeV/c in the centrality class 30%-50%. The measurement of electrons from beauty-hadron decays exploits their larger mean proper decay length cτ≈500 μm compared to that of charm hadrons and most of the other background sources. The v_{2} of electrons from beauty hadron decays at midrapidity is found to be positive with a significance of 3.75 σ. The results provide insights into the degree of thermalization of beauty quarks in the medium. A model assuming full thermalization of beauty quarks is strongly disfavored by the measurement at high p_{T}, but is in agreement with the results at low p_{T}. Transport models including substantial interactions of beauty quarks with an expanding strongly interacting medium describe the measurement within uncertainties.
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Prospects for beyond the Standard Model physics searches at the Deep Underground Neutrino Experiment: DUNE Collaboration. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2021; 81:322. [PMID: 34720713 PMCID: PMC8550327 DOI: 10.1140/epjc/s10052-021-09007-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 02/23/2021] [Indexed: 06/13/2023]
Abstract
The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE's sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach.
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Grants
- MR/T019530/1 Medical Research Council
- MR/T041323/1 Medical Research Council
- MSMT, Czech Republic
- NRF, South Korea
- Canadian Network for Research and Innovation in Machining Technology, Natural Sciences and Engineering Research Council of Canada
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- SERI, Switzerland
- Fundação de Amparo à Pesquisa do Estado de São Paulo
- U.S. Department of Energy
- CERN
- Türkiye Bilimsel ve Teknolojik Arastirma Kurumu
- The Royal Society, United Kingdom
- Canada Foundation for Innovation
- U.S. NSF
- FCT, Portugal
- CEA, France
- CNRS/IN2P3, France
- European Regional Development Fund
- Science and Technology Facilities Council
- H2020-EU, European Union
- IPP, Canada
- Conselho Nacional de Desenvolvimento Científico e Tecnológico
- Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro
- CAM, Spain
- MSCA, European Union
- Instituto Nazionale di Fisica Nucleare
- Fundacção de Amparo à Pesquisa do Estado de Goiás
- Ministerio de Ciencia e Innovación
- Fundacion “La Caixa” Spain
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Cost-effectiveness of Leveraging Social Determinants of Health to Improve Breast, Cervical, and Colorectal Cancer Screening: A Systematic Review. JAMA Oncol 2021; 6:1434-1444. [PMID: 32556187 DOI: 10.1001/jamaoncol.2020.1460] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance Screening for breast, cervical, and colorectal cancers in the United States has remained below the Healthy People 2020 goals, with evidence indicating that persistent screening disparities still exist. The US Department of Health and Human Services has emphasized cross-sectoral collaboration in aligning social determinants of health with public health and medical services. Examining the economics of intervening through these novel methods in the realm of cancer screening can inform program planners, health care providers, implementers, and policy makers. Objective To conduct a systematic review of economic evaluations of interventions leveraging social determinants of health to improve screening for breast, cervical, and colorectal cancer to guide implementation. Evidence Review A systematic literature search for economic evidence was performed in MEDLINE, Embase, PsycINFO, Cochrane Library, Global Health, Scopus, Academic Search Complete, Business Source Complete, EconLit, CINAHL (Cumulative Index to Nursing and Allied Health Literature), ERIC (Education Resources Information Center), and Sociological Abstracts from January 1, 2004, to November 25, 2019. Included studies intervened on social determinants of health to improve breast, cervical, and colorectal cancer screening in the United States and reported intervention cost, incremental cost per additional person screened, and/or incremental cost per quality-adjusted life-year (QALY). Risk of bias was assessed along with qualitative assessment of quality to ensure complete reporting of economic measures, data sources, and analytic methods. In addition, included studies with modeled outcomes had to define structural elements and sources for input parameters, distinguish between programmatic and literature-derived data, and assess uncertainty. Findings Thirty unique articles with 94 706 real and 4.21 million simulated participants satisfied our inclusion criteria and were included in the analysis. The median intervention cost per participant was $123.87 (interquartile interval [IQI], $24.44-$313.19; 34 estimates). The median incremental cost per additional person screened was $250.37 (IQI, $44.67-$609.38; 17 estimates). Studies that modeled final economic outcomes had a median incremental cost per person of $122.96 (IQI, $46.96-$124.80; 5 estimates), a median incremental screening rate of 15% (IQI, 14%-20%; 5 estimates), and a median incremental QALY per person of 0.04 years (IQI, 0.006-0.06 year; 5 estimates). The median incremental cost per QALY gained of $3120.00 (IQI, $782.59-$33 600.00; 5 estimates) was lower than $50 000, an established, conservative threshold of cost-effectiveness. Conclusions and Relevance Interventions focused on social determinants of health to improve breast, cervical, and colorectal cancer screening appear to be cost-effective for underserved, vulnerable populations in the United States. The increased screening rates were associated with earlier diagnosis and treatment and in improved health outcomes with significant gains in QALYs. These findings represent the latest economic evidence to guide implementation of these interventions, which serve the dual purpose of enhancing health equity and economic efficiency.
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Post-load glucose spike is a determinant of post-MI prognosis in patients without known or newly diagnosed diabetes. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.3053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Post-prandial plasma glucose spikes contribute to the progression of atherosclerosis. Glycaemic variability may predict post-ACS prognosis. A third to two-thirds of these patients had diabetes mellitus (DM). Post-ACS prognosis is worse in DM than in those without. This has not been tested in patients without DM.
Purpose
To test whether post-load spike in plasma glucose in patients without known or newly diagnosed DM adversely affects prognosis.
Methods
Retrospective cohort analysis of 847 MI survivors without known or newly diagnosed DM who were followed up for MACE (death and non-fatal MI). The median post-glucose spike (PGS, defined as the difference between the 2h-PG and FPG) was 2.4 mmol/l for the whole cohort and 1.5 mmol/l for the patients with normal glucose tolerance (NGT). Group 1: PGS ≤2.4 mmol/l and Group 2: PGS >2.4 mmom/l were compared using Mann-Whitney test for continuous variables and chi-squared test for categorical variables. Event free survival in the two groups was estimated from the Kaplan–Meier curves and compared using log-rank test. Cox proportional hazard regression identified predictors of MACE. Continuous net reclassification improvement (NRI>0) and integrated discrimination improvement (IDI) and c-statistics determined the added predictive value of glycaemic matrices
Results
MACE was higher in group 2 (OR 1.99, 95% CI 1.36 to 2.91, p=0.0004) compared to group 1. In patients with NGT, MACE was higher in patients with PGS ≥1.5 mmol/l vs those below (OR 2.37, 95% CI 1.31 to 4.26, p=0.0041). Event free survival was worse in pre-diabetes than in the NGT groups (HR 1.57, 95% CI 1.17 to 2.12, p=0.003). and in group 2 than 1 (HR 2.01, 95% CI 1.49 to 2.71, p<0.001). Amongst the patients with NGT, event free survival was worse in patients with PGS ≥1.5 mmol/l (HR 2.09, 95% CI 1.35 to 3.25, p<0.001). PGS independently predicted MACE in the whole cohort (HR 1.16, 95% CI 1.06 to 1.26, p=0.002) and NGT group (HR 2.06, 95% 1.51 to 2.79, p<0.000). Group 2 independently predicted MACE in the whole cohort (HR 1.75, 95% CI 1.26 to 2.42, p<0.001). In the NGT group, PGS >median, independently predicted of MACE (HR 2.67, 95% CI 1.54 to 4.61, p<0.001). The c-statistic a model containing GRS only increased on addition of PGS (δAUC 0.0134, p=0.046) but not on addition of FPG. Within the whole cohort, PGS improved the net reclassification by 28% when added to the model containing GRS only. NGT cohort had higher net improvement at 46.6%. Addition of PGS to the model containing GRS and FPG resulted in NRI>0 of 25.5% in the whole cohort and 56.3% in the NGT cohort. Similar changes were seen in the IDI.
Conclusion(s)
PGS predicts post MI prognosis in patients without known or newly diagnosed DM including in patients with NGT. This suggests that PGS is a more powerful indicator of post-MI prognosis than FPG
Funding Acknowledgement
Type of funding source: None
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Does high-normal 2-hour post load plasma glucose after myocardial infarction in patients with normal glucose tolerance adversely affect prognosis? Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.3054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Type 2 diabetes mellitus (DM) and pre-DM, newly diagnosed after MI in patients without known DM adversely affects prognosis. 2-hour post-load glucose (2h-PG) predicts post-MI prognosis better than fasting plasma glucose (FPG). Plasma glucose below the conventional threshold for the diagnosis of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), affects post-MI prognosis.
Purpose
To test whether high-normal post-load plasma glucose in patients with normal glucose tolerance (NGT) would affect post-MI prognosis and whether FPG or 2h-PG increases this risk.
Methods
Retrospective cohort analysis of 425 MI survivors without known DM and with NGT followed up for (death and non-fatal MI) as MACE. MACE in patients with 2h-PG > median for the whole cohort (Group 2), was compared with those at or below (Group 1). Event free survival in the two groups was estimated from the Kaplan–Meier curves and compared using log-rank test. Cox proportional hazard regression identified predictors of MACE. Continuous net reclassification improvement (NRI>0) and integrated discrimination improvement (IDI) and c-statistics determined the added predictive value of glycaemic matrices.
Results
Median 2h-PG was 6.3 mmol/l. 219 patients in Group 1 and 206 in Group 2. Group 2 had higher age, prevalence of hypertension, hypercholesterolaemia, ST-segment depression and higher heart rate and GRACE scores. Median follow-up was 40.6 months. MACE was more frequent in Group 2 than Group 1 (OR 2.82, 95% CI 1.55 to 5.16, p<0.001). MACE-free survival was higher in Group 1 (HR 2.43, 95% CI 1.53 to 3.85, p<0.001). Group 2 (HR 2.42, 95% CI 1.44 to 4.04, p<0.001) predicted the MACE-free survival. 2h-PG, but not the FPG independently predicted of MACE (HR 1.73, 95% CI 1.31 to 2.30, p<0.001). Addition of 2h-PG to models containing FPG and other variables improved their predictive performance (NRI>0 0.5062, p<0.001; IDI 0.0376, p=0.003). The c-statistic increased when 2h-PG was added to the GRACE score only model (δAUC 0.037, 95% CI 0.012 to 0.081, p=0.046).
Conclusion(s)
This study suggests that “high-normal” 2h-PG is an independent predictor of post-MI prognosis. Normoglycaemic patients with 2h-PG ≥6.4 mmol/l, had worse post-MI prognosis compared to those with 2h-PG ≤6.3 mmol/l. The risk of MACE increased with increasing 2h-PG within the normal range. FPG had no effect on prognosis.
Funding Acknowledgement
Type of funding source: None
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Measurement of the Low-Energy Antideuteron Inelastic Cross Section. PHYSICAL REVIEW LETTERS 2020; 125:162001. [PMID: 33124836 DOI: 10.1103/physrevlett.125.162001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/10/2020] [Accepted: 09/09/2020] [Indexed: 06/11/2023]
Abstract
In this Letter, we report the first measurement of the inelastic cross section for antideuteron-nucleus interactions at low particle momenta, covering a range of 0.3≤p<4 GeV/c. The measurement is carried out using p-Pb collisions at a center-of-mass energy per nucleon-nucleon pair of sqrt[s_{NN}]=5.02 TeV, recorded with the ALICE detector at the CERN LHC and utilizing the detector material as an absorber for antideuterons and antiprotons. The extracted raw primary antiparticle-to-particle ratios are compared to the results from detailed ALICE simulations based on the geant4 toolkit for the propagation of (anti)particles through the detector material. The analysis of the raw primary (anti)proton spectra serves as a benchmark for this study, since their hadronic interaction cross sections are well constrained experimentally. The first measurement of the inelastic cross section for antideuteron-nucleus interactions averaged over the ALICE detector material with atomic mass numbers ⟨A⟩=17.4 and 31.8 is obtained. The measured inelastic cross section points to a possible excess with respect to the Glauber model parametrization used in geant4 in the lowest momentum interval of 0.3≤p<0.47 GeV/c up to a factor 2.1. This result is relevant for the understanding of antimatter propagation and the contributions to antinuclei production from cosmic ray interactions within the interstellar medium. In addition, the momentum range covered by this measurement is of particular importance to evaluate signal predictions for indirect dark-matter searches.
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Intestinal microbiota and vaccine efficacy in children from resource poor settings - potential impact for the usefulness of probiotics? Benef Microbes 2020; 11:319-328. [PMID: 32720834 DOI: 10.3920/bm2019.0155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Developing countries continue to contribute significantly to the global burden of childhood mortality due to infectious diseases. Infections leading to diseases like diarrhoea, pneumonia and meningitis account for millions of deaths annually. Most of these diseases are preventable by vaccination and therefore global vaccination rates have risen substantially with clear benefits. But paradoxically, the vaccines have demonstrated lower immunogenicity in developing countries as compared to their industrialised counterparts. Malnutrition in resource poor settings along with repeated polymicrobial infections at early age are some of the reasons for the differences in vaccine efficacy in different settings. Recent studies indicate that the gastrointestinal microbiota possibly influences maturation of immune system as well as vaccine efficacy. In this review we discuss evidences from in vitro, animal and human studies showing that probiotics can positively modulate gut microbiota composition and exert immunomodulatory effects on the host. We also discuss how they should be evaluated for their ability to improve vaccine performance especially in low resource settings.
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Probing the Effects of Strong Electromagnetic Fields with Charge-Dependent Directed Flow in Pb-Pb Collisions at the LHC. PHYSICAL REVIEW LETTERS 2020; 125:022301. [PMID: 32701333 DOI: 10.1103/physrevlett.125.022301] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 04/22/2020] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
The first measurement at the LHC of charge-dependent directed flow (v_{1}) relative to the spectator plane is presented for Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV. Results are reported for charged hadrons and D^{0} mesons for the transverse momentum intervals p_{T}>0.2 GeV/c and 3<p_{T}<6 GeV/c in the 5%-40% and 10%-40% centrality classes, respectively. The difference between the positively and negatively charged hadron v_{1} has a positive slope as a function of pseudorapidity η, dΔv_{1}/dη=[1.68±0.49(stat)±0.41(syst)]×10^{-4}. The same measurement for D^{0} and D[over ¯]^{0} mesons yields a positive value dΔv_{1}/dη=[4.9±1.7(stat)±0.6(syst)]×10^{-1}, which is about 3 orders of magnitude larger than the one of the charged hadrons. These measurements can provide new insights into the effects of the strong electromagnetic field and the initial tilt of matter created in noncentral heavy ion collisions on the dynamics of light (u, d, and s) and heavy (c) quarks. The large difference between the observed Δv_{1} of charged hadrons and D^{0} mesons may reflect different sensitivity of the charm and light quarks to the early time dynamics of a heavy ion collision. These observations challenge some recent theoretical calculations, which predicted a negative and an order of magnitude smaller value of dΔv_{1}/dη for both light flavor and charmed hadrons.
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Evidence of Spin-Orbital Angular Momentum Interactions in Relativistic Heavy-Ion Collisions. PHYSICAL REVIEW LETTERS 2020; 125:012301. [PMID: 32678650 DOI: 10.1103/physrevlett.125.012301] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 02/25/2020] [Accepted: 05/27/2020] [Indexed: 06/11/2023]
Abstract
The first evidence of spin alignment of vector mesons (K^{*0} and ϕ) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The spin density matrix element ρ_{00} is measured at midrapidity (|y|<0.5) in Pb-Pb collisions at a center-of-mass energy (sqrt[s_{NN}]) of 2.76 TeV with the ALICE detector. ρ_{00} values are found to be less than 1/3 (1/3 implies no spin alignment) at low transverse momentum (p_{T}<2 GeV/c) for K^{*0} and ϕ at a level of 3σ and 2σ, respectively. No significant spin alignment is observed for the K_{S}^{0} meson (spin=0) in Pb-Pb collisions and for the vector mesons in pp collisions. The measured spin alignment is unexpectedly large but qualitatively consistent with the expectation from models which attribute it to a polarization of quarks in the presence of angular momentum in heavy-ion collisions and a subsequent hadronization by the process of recombination.
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Observation of giant spin-split Fermi-arc with maximal Chern number in the chiral topological semimetal PtGa. Nat Commun 2020; 11:2033. [PMID: 32341390 PMCID: PMC7184610 DOI: 10.1038/s41467-020-15865-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 04/01/2020] [Indexed: 11/08/2022] Open
Abstract
Non-symmorphic chiral topological crystals host exotic multifold fermions, and their associated Fermi arcs helically wrap around and expand throughout the Brillouin zone between the high-symmetry center and surface-corner momenta. However, Fermi-arc splitting and realization of the theoretically proposed maximal Chern number rely heavily on the spin-orbit coupling (SOC) strength. In the present work, we investigate the topological states of a new chiral crystal, PtGa, which has the strongest SOC among all chiral crystals reported to date. With a comprehensive investigation using high-resolution angle-resolved photoemission spectroscopy, quantum-oscillation measurements, and state-of-the-art ab initio calculations, we report a giant SOC-induced splitting of both Fermi arcs and bulk states. Consequently, this study experimentally confirms the realization of a maximal Chern number equal to ±4 in multifold fermionic systems, thereby providing a platform to observe large-quantized photogalvanic currents in optical experiments.
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Scattering Studies with Low-Energy Kaon-Proton Femtoscopy in Proton-Proton Collisions at the LHC. PHYSICAL REVIEW LETTERS 2020; 124:092301. [PMID: 32202883 DOI: 10.1103/physrevlett.124.092301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 12/03/2019] [Accepted: 02/11/2020] [Indexed: 06/10/2023]
Abstract
The study of the strength and behavior of the antikaon-nucleon (K[over ¯]N) interaction constitutes one of the key focuses of the strangeness sector in low-energy quantum chromodynamics (QCD). In this Letter a unique high-precision measurement of the strong interaction between kaons and protons, close and above the kinematic threshold, is presented. The femtoscopic measurements of the correlation function at low pair-frame relative momentum of (K^{+}p⊕K^{-}p[over ¯]) and (K^{-}p⊕K^{+}p[over ¯]) pairs measured in pp collisions at sqrt[s]=5, 7, and 13 TeV are reported. A structure observed around a relative momentum of 58 MeV/c in the measured correlation function of (K^{-}p⊕K^{+}p[over ¯]) with a significance of 4.4σ constitutes the first experimental evidence for the opening of the (K[over ¯]^{0}n⊕K^{0}n[over ¯]) isospin breaking channel due to the mass difference between charged and neutral kaons. The measured correlation functions have been compared to Jülich and Kyoto models in addition to the Coulomb potential. The high-precision data at low relative momenta presented in this work prove femtoscopy to be a powerful complementary tool to scattering experiments and provide new constraints above the K[over ¯]N threshold for low-energy QCD chiral models.
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Influence of family history on risk of second primary cancers and survival in patients with squamous cell skin cancer. Br J Dermatol 2020; 183:488-494. [PMID: 31853941 DOI: 10.1111/bjd.18809] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Patients with squamous cell skin cancer (SCC) have an excellent prognosis but second primary cancers (SPCs) weaken survival prospects. Family history is a known risk factor for cancer but whether it is a risk factor for SPC in patients with SCC is not known. OBJECTIVES To quantify the risk of family history on SPCs in patients with SCC and estimate survival probabilities of patients with SPCs depending on family history. METHODS With 13 945 histologically verified SCCs, relative risks (RRs) were estimated for family history using a generalized regression model. For survival analysis, hazard ratios (HRs) were assessed using a multivariable Cox proportional-hazards model. RESULTS Family history of invasive SCC increased risk of second invasive SCC [RR = 42·92, 95% confidence interval (CI) 33·69-50·32] compared with risk without family history (RR 19·12, 95% CI 17·88-21·08). Family history of any nonskin cancer in invasive SCC increased risk of the same cancers to be diagnosed as SPC (RRFH = 1·48, 95% CI 1·35-1·61 vs. RRno FH = 1·40, 95% CI 1·32-1·48); significant increases were observed for seven different nonskin cancers. Most results were replicated for in situ SCC. SPC was deleterious for survival irrespective of family history; HR for patients with SPC was 4·28 (95% CI 3·83-4·72) vs. those without SPC (1·04). CONCLUSIONS Family history of nonskin cancer was associated with approximately a doubling of risk for SPCs in patients with SCC. SPC increases the death rate in patients with SCC 3-4 times, irrespective of family history. Taking family history into account at SCC diagnosis may help prevention or early detection of SPCs. What's already known about this topic? Second primary cancers (SPCs) are frequently diagnosed in patients with invasive and in situ squamous cell carcinoma (SCC); some epidemiological studies suggest a link to immune dysfunction. Family history of cancer is a risk factor for practically all first primary cancers but whether it also influences risk of SPCs in patients with SCC is not known. The possible influence of family history on survival in patients with SCC remains to be established. Linked Comment: Youlden and Baade. Br J Dermatol 2020; 183:414-415.
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Measurement of ϒ(1S) Elliptic Flow at Forward Rapidity in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV. PHYSICAL REVIEW LETTERS 2019; 123:192301. [PMID: 31765217 DOI: 10.1103/physrevlett.123.192301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/09/2019] [Indexed: 06/10/2023]
Abstract
The first measurement of the ϒ(1S) elliptic flow coefficient (v_{2}) is performed at forward rapidity (2.5<y<4) in Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV with the ALICE detector at the LHC. The results are obtained with the scalar product method and are reported as a function of transverse momentum (p_{T}) up to 15 GeV/c in the 5%-60% centrality interval. The measured ϒ(1S)v_{2} is consistent with 0 and with the small positive values predicted by transport models within uncertainties. The v_{2} coefficient in 2<p_{T}<15 GeV/c is lower than that of inclusive J/ψ mesons in the same p_{T} interval by 2.6 standard deviations. These results, combined with earlier suppression measurements, are in agreement with a scenario in which the ϒ(1S) production in Pb-Pb collisions at LHC energies is dominated by dissociation limited to the early stage of the collision, whereas in the J/ψ case there is substantial experimental evidence of an additional regeneration component.
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First Observation of the Directed Flow of D^{0} and D^{0}[over ¯] in Au+Au Collisions at sqrt[s_{NN}]=200 GeV. PHYSICAL REVIEW LETTERS 2019; 123:162301. [PMID: 31702332 DOI: 10.1103/physrevlett.123.162301] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 08/09/2019] [Indexed: 06/10/2023]
Abstract
We report the first measurement of rapidity-odd directed flow (v_{1}) for D^{0} and D^{0}[over ¯] mesons at midrapidity (|y|<0.8) in Au+Au collisions at sqrt[s_{NN}]=200 GeV using the STAR detector at the Relativistic Heavy Ion Collider. In 10-80% Au+Au collisions, the slope of the v_{1} rapidity dependence (dv_{1}/dy), averaged over D^{0} and D^{0}[over ¯] mesons, is -0.080±0.017(stat)±0.016(syst) for transverse momentum p_{T} above 1.5 GeV/c. The absolute value of D^{0} meson dv_{1}/dy is about 25 times larger than that for charged kaons, with 3.4σ significance. These data give a unique insight into the initial tilt of the produced matter, and offer constraints on the geometric and transport parameters of the hot QCD medium created in relativistic heavy-ion collisions.
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