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Viviani M, Girlanda L, Kievsky A, Logoteta D, Marcucci LE. Theoretical Study of the d(d, p)^{3}H and d(d, n)^{3}He Processes at Low Energies. PHYSICAL REVIEW LETTERS 2023; 130:122501. [PMID: 37027864 DOI: 10.1103/physrevlett.130.122501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/28/2022] [Accepted: 02/16/2023] [Indexed: 06/19/2023]
Abstract
We present a theoretical study of the processes d(d,p)^{3}H and d(d,n)^{3}He at energies of interest for energy production and for big-bang nucleosynthesis. We accurately solve the four body scattering problem using the ab initio hyperspherical harmonics method, starting from nuclear Hamiltonians which include modern two- and three-nucleon interactions, derived in chiral effective field theory. We report results for the astrophysical S factor, the quintet suppression factor, and various single and double polarized observables. A first estimate of the theoretical uncertainty for all these quantities is provided by varying the cutoff parameter used to regularize the chiral interactions at high momentum.
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Apponi A, Betti M, Borghesi M, Boyarsky A, Canci N, Cavoto G, Chang C, Cheianov V, Cheipesh Y, Chung W, Cocco A, Colijn A, D’Ambrosio N, de Groot N, Esposito A, Faverzani M, Ferella A, Ferri E, Ficcadenti L, Frederico T, Gariazzo S, Gatti F, Gentile C, Giachero A, Hochberg Y, Kahn Y, Lisanti M, Mangano G, Marcucci L, Mariani C, Marques M, Menichetti G, Messina M, Mikulenko O, Monticone E, Nucciotti A, Orlandi D, Pandolfi F, Parlati S, Pepe C, Pérez de los Heros C, Pisanti O, Polini M, Polosa A, Puiu A, Rago I, Raitses Y, Rajteri M, Rossi N, Rozwadowska K, Rucandio I, Ruocco A, Strid C, Tan A, Teles L, Tozzini V, Tully C, Viviani M, Zeitler U, Zhao F. Heisenberg’s uncertainty principle in the PTOLEMY project: A theory update. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.053002] [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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Mossa V, Stöckel K, Cavanna F, Ferraro F, Aliotta M, Barile F, Bemmerer D, Best A, Boeltzig A, Broggini C, Bruno CG, Caciolli A, Chillery T, Ciani GF, Corvisiero P, Csedreki L, Davinson T, Depalo R, Di Leva A, Elekes Z, Fiore EM, Formicola A, Fülöp Z, Gervino G, Guglielmetti A, Gustavino C, Gyürky G, Imbriani G, Junker M, Kievsky A, Kochanek I, Lugaro M, Marcucci LE, Mangano G, Marigo P, Masha E, Menegazzo R, Pantaleo FR, Paticchio V, Perrino R, Piatti D, Pisanti O, Prati P, Schiavulli L, Straniero O, Szücs T, Takács MP, Trezzi D, Viviani M, Zavatarelli S. The baryon density of the Universe from an improved rate of deuterium burning. Nature 2020; 587:210-213. [PMID: 33177669 DOI: 10.1038/s41586-020-2878-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 09/16/2020] [Indexed: 11/09/2022]
Abstract
Light elements were produced in the first few minutes of the Universe through a sequence of nuclear reactions known as Big Bang nucleosynthesis (BBN)1,2. Among the light elements produced during BBN1,2, deuterium is an excellent indicator of cosmological parameters because its abundance is highly sensitive to the primordial baryon density and also depends on the number of neutrino species permeating the early Universe. Although astronomical observations of primordial deuterium abundance have reached percent accuracy3, theoretical predictions4-6 based on BBN are hampered by large uncertainties on the cross-section of the deuterium burning D(p,γ)3He reaction. Here we show that our improved cross-sections of this reaction lead to BBN estimates of the baryon density at the 1.6 percent level, in excellent agreement with a recent analysis of the cosmic microwave background7. Improved cross-section data were obtained by exploiting the negligible cosmic-ray background deep underground at the Laboratory for Underground Nuclear Astrophysics (LUNA) of the Laboratori Nazionali del Gran Sasso (Italy)8,9. We bombarded a high-purity deuterium gas target10 with an intense proton beam from the LUNA 400-kilovolt accelerator11 and detected the γ-rays from the nuclear reaction under study with a high-purity germanium detector. Our experimental results settle the most uncertain nuclear physics input to BBN calculations and substantially improve the reliability of using primordial abundances to probe the physics of the early Universe.
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Higgins MD, Greene CH, Kievsky A, Viviani M. Nonresonant Density of States Enhancement at Low Energies for Three or Four Neutrons. PHYSICAL REVIEW LETTERS 2020; 125:052501. [PMID: 32794850 DOI: 10.1103/physrevlett.125.052501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/26/2020] [Accepted: 07/06/2020] [Indexed: 06/11/2023]
Abstract
The low energy systems of three or four neutrons are treated within the adiabatic hyperspherical framework, yielding an understanding of the low energy quantum states in terms of an adiabatic potential energy curve. The dominant low energy potential curve for each system, computed here using widely accepted nucleon-nucleon interactions with and without the inclusion of a three-nucleon force, shows no sign of a low energy resonance. However, both systems exhibit a low energy enhancement of the density of states, or of the Wigner-Smith time delay, which derives from long-range universal physics analogous to the Efimov effect. That enhancement could be relevant to understanding the low energy excess of correlated four-neutron ejection events observed experimentally in a nuclear reaction by Kisamori et al. [Phys. Rev. Lett. 116, 052501 (2016)PRLTAO0031-900710.1103/PhysRevLett.116.052501].
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Marcucci LE, Schiavilla R, Viviani M. Erratum: Proton-Proton Weak Capture in Chiral Effective Field Theory [Phys. Rev. Lett. 110, 192503 (2013)]. PHYSICAL REVIEW LETTERS 2019; 123:019901. [PMID: 31386412 DOI: 10.1103/physrevlett.123.019901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Indexed: 06/10/2023]
Abstract
This corrects the article DOI: 10.1103/PhysRevLett.110.192503.
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Presto S, Artini C, Pani M, Carnasciali MM, Massardo S, Viviani M. Ionic conductivity and local structural features in Ce 1-xSm xO 2-x/2. Phys Chem Chem Phys 2018; 20:28338-28345. [PMID: 30398485 DOI: 10.1039/c8cp04186e] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sm-Doped ceria is one of the most promising materials to be used as electrolyte in solid oxide fuel cells due to its remarkable ionic conductivity values in the intermediate temperature range. Transport properties and local structural features of Ce1-xSmxO2-x/2 (0.1 ≤ x ≤ 0.7) were studied by an impedance/μ-Raman spectroscopy coupled approach up to 1073 K. Results suggest that C-based nanosized defect clusters are responsible for the drop in ionic conductivity observed even at x = 0.2, i.e. at a Sm content lower than necessary to allow C domains to reach the percolation threshold through crystallites. Moreover, within the fluorite-type compositional region, with increasing the Sm content, defect clusters undergo a rearrangement resulting in the enlargement of C-based domains rather than in the increase of their number; at higher x, on the contrary, both the size and amount of C domains increase in parallel.
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Kievsky A, Viviani M, Logoteta D, Bombaci I, Girlanda L. Correlations imposed by the unitary limit between few-nucleon systems, nuclear matter, and neutron stars. PHYSICAL REVIEW LETTERS 2018; 121:072701. [PMID: 30169068 DOI: 10.1103/physrevlett.121.072701] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/04/2018] [Indexed: 06/08/2023]
Abstract
The large values of the singlet and triplet two-nucleon scattering lengths locate the nuclear system close to the unitary limit. This particular position strongly constrains the low-energy observables in the three-nucleon system as depending on one parameter, the triton binding energy, and introduces correlations in the low-energy sector of light nuclei. Here we analyze the propagation of these correlations to infinite nuclear matter showing that its saturation properties, the equation of state of β-stable nuclear matter, and several properties of neutron stars, as their maximum mass, are well determined solely by a few number of low-energy quantities of the two- and three-nucleon systems. In this way we make a direct link between the universal behavior observed in the low-energy region of few-nucleon systems and fundamental properties of nuclear matter and neutron stars.
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Marcucci LE, Kievsky A, Rosati S, Schiavilla R, Viviani M. Erratum: Chiral Effective Field Theory Predictions for Muon Capture on Deuteron and ^{3}He [Phys. Rev. Lett. 108, 052502 (2012)]. PHYSICAL REVIEW LETTERS 2018; 121:049901. [PMID: 30095967 DOI: 10.1103/physrevlett.121.049901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Indexed: 06/08/2023]
Abstract
This corrects the article DOI: 10.1103/PhysRevLett.108.052502.
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Piarulli M, Baroni A, Girlanda L, Kievsky A, Lovato A, Lusk E, Marcucci LE, Pieper SC, Schiavilla R, Viviani M, Wiringa RB. Light-Nuclei Spectra from Chiral Dynamics. PHYSICAL REVIEW LETTERS 2018; 120:052503. [PMID: 29481181 DOI: 10.1103/physrevlett.120.052503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Indexed: 06/08/2023]
Abstract
In recent years local chiral interactions have been derived and implemented in quantum Monte Carlo methods in order to test to what extent the chiral effective field theory framework impacts our knowledge of few- and many-body systems. In this Letter, we present Green's function Monte Carlo calculations of light nuclei based on the family of local two-body interactions presented by our group in a previous paper in conjunction with chiral three-body interactions fitted to bound- and scattering-state observables in the three-nucleon sector. These interactions include Δ intermediate states in their two-pion-exchange components. We obtain predictions for the energy levels and level ordering of nuclei in the mass range A=4-12, accurate to ≤2% of the binding energy, in very satisfactory agreement with experimental data.
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Camsonne A, Katramatou AT, Olson M, Acha A, Allada K, Anderson BD, Arrington J, Baldwin A, Chen JP, Choi S, Chudakov E, Cisbani E, Craver B, Decowski P, Dutta C, Folts E, Frullani S, Garibaldi F, Gilman R, Gomez J, Hahn B, Hansen JO, Higinbotham DW, Holmstrom T, Huang J, Iodice M, Jiang X, Kelleher A, Khrosinkova E, Kievsky A, Kuchina E, Kumbartzki G, Lee B, LeRose JJ, Lindgren RA, Lott G, Lu H, Marcucci LE, Margaziotis DJ, Markowitz P, Marrone S, Meekins D, Meziani ZE, Michaels R, Moffit B, Norum B, Petratos GG, Puckett A, Qian X, Rondon O, Saha A, Sawatzky B, Segal J, Shabestari M, Shahinyan A, Solvignon P, Sparveris N, Subedi RR, Suleiman R, Sulkosky V, Urciuoli GM, Viviani M, Wang Y, Wojtsekhowski BB, Yan X, Yao H, Zhang WM, Zheng X, Zhu L. Publisher's Note: JLab Measurements of the ^{3}He Form Factors at Large Momentum Transfers [Phys. Rev. Lett. 119, 162501 (2017)]. PHYSICAL REVIEW LETTERS 2017; 119:209901. [PMID: 29219338 DOI: 10.1103/physrevlett.119.209901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Indexed: 06/07/2023]
Abstract
This corrects the article DOI: 10.1103/PhysRevLett.119.162501.
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Camsonne A, Katramatou AT, Olson M, Acha A, Allada K, Anderson BD, Arrington J, Baldwin A, Chen JP, Choi S, Chudakov E, Cisbani E, Craver B, Decowski P, Dutta C, Folts E, Frullani S, Garibaldi F, Gilman R, Gomez J, Hahn B, Hansen JO, Higinbotham DW, Holmstrom T, Huang J, Iodice M, Jiang X, Kelleher A, Khrosinkova E, Kievsky A, Kuchina E, Kumbartzki G, Lee B, LeRose JJ, Lindgren RA, Lott G, Lu H, Marcucci LE, Margaziotis DJ, Markowitz P, Marrone S, Meekins D, Meziani ZE, Michaels R, Moffit B, Norum B, Petratos GG, Puckett A, Qian X, Rondon O, Saha A, Sawatzky B, Segal J, Shabestari M, Shahinyan A, Solvignon P, Sparveris N, Subedi RR, Suleiman R, Sulkosky V, Urciuoli GM, Viviani M, Wang Y, Wojtsekhowski BB, Yan X, Yao H, Zhang WM, Zheng X, Zhu L. JLab Measurements of the ^{3}He Form Factors at Large Momentum Transfers. PHYSICAL REVIEW LETTERS 2017; 119:162501. [PMID: 29099223 DOI: 10.1103/physrevlett.119.162501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Indexed: 06/07/2023]
Abstract
The charge and magnetic form factors, F_{C} and F_{M}, respectively, of ^{3}He are extracted in the kinematic range 25 fm^{-2}≤Q^{2}≤61 fm^{-2} from elastic electron scattering by detecting ^{3}He recoil nuclei and scattered electrons in coincidence with the two High Resolution Spectrometers of the Hall A Facility at Jefferson Lab. The measurements find evidence for the existence of a second diffraction minimum for the magnetic form factor at Q^{2}=49.3 fm^{-2} and for the charge form factor at Q^{2}=62.0 fm^{-2}. Both minima are predicted to exist in the Q^{2} range accessible by this Jefferson Lab experiment. The data are in qualitative agreement with theoretical calculations based on realistic interactions and accurate methods to solve the three-body nuclear problem.
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Williams KE, Berthelsen D, Viviani M, Nicholson JM. Participation of Australian Aboriginal and Torres Strait Islander families in a parent support programme: longitudinal associations between playgroup attendance and child, parent and community outcomes. Child Care Health Dev 2017; 43:441-450. [PMID: 27739085 DOI: 10.1111/cch.12417] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 08/29/2016] [Accepted: 09/12/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND Playgroups are a relatively unique form of family support programme that is common in Australia which has high community acceptance and significant government investment. However, limited evidence exists regarding the effectiveness of playgroups to achieve better outcomes for children and their parents. This study describes patterns of playgroup participation for Aboriginal and Torres Strait Islander families with young children and examines the extent to which participation from birth to three years is associated with subsequent child, parent and community outcomes. METHODS This study uses three years of longitudinal data for 622 Aboriginal and Torres Strait Islander children who were participants in the Longitudinal Study of Indigenous Children (LSIC). Longitudinal associations between playgroup attendance when children were age 2 and 3 years and outcome measures for child vocabulary, motor skills, behaviour problems, prosocial development, parent home learning engagement, resilience, advice-seeking and health service use, and community trustworthiness were examined using path analysis. RESULTS Rates of playgroup participation in this sample group were generally lower than for Australian children overall. Playgroup attendance when children were age 2 to 3 years was associated with higher parental engagement in home learning activities when children were aged 4 years which, in turn, was associated with stronger expressive vocabulary scores for children. CONCLUSION The findings from this study suggest that playgroup participation can enhance the home learning environments for Aboriginal and Torres Strait Islander children. Playgroups as a parent support programme hold strong potential to reach and engage families, particularly in areas of high geographic isolation, which can realize improved outcomes for children, parents and communities.
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de Paula W, Frederico T, Salmè G, Viviani M. Advances in solving the two-fermion homogeneous Bethe-Salpeter equation in Minkowski space. Int J Clin Exp Med 2016. [DOI: 10.1103/physrevd.94.071901] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Marcucci LE, Mangano G, Kievsky A, Viviani M. Erratum: Implication of the Proton-Deuteron Radiative Capture for Big Bang Nucleosynthesis [Phys. Rev. Lett. 116, 102501 (2016)]. PHYSICAL REVIEW LETTERS 2016; 117:049901. [PMID: 27494504 DOI: 10.1103/physrevlett.117.049901] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Indexed: 06/06/2023]
Abstract
This corrects the article DOI: 10.1103/PhysRevLett.116.102501.
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Marcucci LE, Mangano G, Kievsky A, Viviani M. Implication of the Proton-Deuteron Radiative Capture for Big Bang Nucleosynthesis. PHYSICAL REVIEW LETTERS 2016; 116:102501. [PMID: 27015474 DOI: 10.1103/physrevlett.116.102501] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Indexed: 06/05/2023]
Abstract
The astrophysical S factor for the radiative capture d(p,γ)^{3}He in the energy range of interest for big bang nucleosynthesis (BBN) is calculated using an ab initio approach. The nuclear Hamiltonian retains both two- and three-nucleon interactions-the Argonne v_{18} and the Urbana IX, respectively. Both one- and many-body contributions to the nuclear current operator are included. The former retain for the first time, besides the 1/m leading order contribution (m is the nucleon mass), also the next-to-leading order term, proportional to 1/m^{3}. The many-body currents are constructed in order to satisfy the current conservation relation with the adopted Hamiltonian model. The hyperspherical harmonics technique is applied to solve the A=3 bound and scattering states. Particular attention is paid in this second case in order to obtain, in the energy range of BBN, an uncertainty on the astrophysical S factor of the order or below ∼1%. Then, in this energy range, the S factor is found to be ∼10% larger than the currently adopted values. Part of this increase (1%-3%) is due to the 1/m^{3} one-body operator, while the remaining is due to the new more accurate scattering wave functions. We have studied the implication of this new determination for the d(p,γ)^{3}He S factor on the deuterium primordial abundance. We find that the predicted theoretical value for ^{2}H/H is in excellent agreement with its experimental determination, using the most recent determination of the baryon density of the Planck experiment, and with a standard number of relativistic degrees of freedom N_{eff}=3.046 during primordial nucleosynthesis. This calls for a more accurate measurement of the astrophysical S factor in order to confirm the present predictions.
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Mihovilovič M, Jin G, Long E, Zhang YW, Allada K, Anderson B, Annand JRM, Averett T, Boeglin W, Bradshaw P, Camsonne A, Canan M, Cates GD, Chen C, Chen JP, Chudakov E, De Leo R, Deng X, Deltuva A, Deur A, Dutta C, El Fassi L, Flay D, Frullani S, Garibaldi F, Gao H, Gilad S, Gilman R, Glamazdin O, Golak J, Golge S, Gomez J, Hansen O, Higinbotham DW, Holmstrom T, Huang J, Ibrahim H, de Jager CW, Jensen E, Jiang X, Jones M, Kang H, Katich J, Khanal HP, Kievsky A, King P, Korsch W, LeRose J, Lindgren R, Lu HJ, Luo W, Marcucci LE, Markowitz P, Meziane M, Michaels R, Moffit B, Monaghan P, Muangma N, Nanda S, Norum BE, Pan K, Parno D, Piasetzky E, Posik M, Punjabi V, Puckett AJR, Qian X, Qiang Y, Qui X, Riordan S, Saha A, Sauer PU, Sawatzky B, Schiavilla R, Schoenrock B, Shabestari M, Shahinyan A, Širca S, Skibiński R, John JS, Subedi R, Sulkosky V, Tobias WA, Tireman W, Urciuoli GM, Viviani M, Wang D, Wang K, Wang Y, Watson J, Wojtsekhowski B, Witała H, Ye Z, Zhan X, Zhang Y, Zheng X, Zhao B, Zhu L. Measurement of double-polarization asymmetries in the quasielastic (3)He[→](e[→],e(')d) process. PHYSICAL REVIEW LETTERS 2014; 113:232505. [PMID: 25526124 DOI: 10.1103/physrevlett.113.232505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Indexed: 06/04/2023]
Abstract
We present a precise measurement of double-polarization asymmetries in the ^{3}He[over →](e[over →],e^{'}d) reaction. This particular process is a uniquely sensitive probe of hadron dynamics in ^{3}He and the structure of the underlying electromagnetic currents. The measurements have been performed in and around quasielastic kinematics at Q^{2}=0.25(GeV/c)^{2} for missing momenta up to 270 MeV/c. The asymmetries are in fair agreement with the state-of-the-art calculations in terms of their functional dependencies on p_{m} and ω, but are systematically offset. Beyond the region of the quasielastic peak, the discrepancies become even more pronounced. Thus, our measurements have been able to reveal deficiencies in the most sophisticated calculations of the three-body nuclear system, and indicate that further refinement in the treatment of their two-and/or three-body dynamics is required.
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Silvestri L, de la Cal MA, Cerda E, Viviani M, van Saene HKF. Use of enteral vancomycin for meticillin resistant Staphylococcus aureus (MRSA) in intensive care. BMJ 2014; 348:g2594. [PMID: 24709856 DOI: 10.1136/bmj.g2594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Camsonne A, Katramatou AT, Olson M, Sparveris N, Acha A, Allada K, Anderson BD, Arrington J, Baldwin A, Chen JP, Choi S, Chudakov E, Cisbani E, Craver B, Decowski P, Dutta C, Folts E, Frullani S, Garibaldi F, Gilman R, Gomez J, Hahn B, Hansen JO, Higinbotham DW, Holmstrom T, Huang J, Iodice M, Jiang X, Kelleher A, Khrosinkova E, Kievsky A, Kuchina E, Kumbartzki G, Lee B, LeRose JJ, Lindgren RA, Lott G, Lu H, Marcucci LE, Margaziotis DJ, Markowitz P, Marrone S, Meekins D, Meziani ZE, Michaels R, Moffit B, Norum B, Petratos GG, Puckett A, Qian X, Rondon O, Saha A, Sawatzky B, Segal J, Shabestari M, Shahinyan A, Solvignon P, Subedi RR, Suleiman R, Sulkosky V, Urciuoli GM, Viviani M, Wang Y, Wojtsekhowski BB, Yan X, Yao H, Zhang WM, Zheng X, Zhu L. JLab measurement of the 4He charge form factor at large momentum transfers. PHYSICAL REVIEW LETTERS 2014; 112:132503. [PMID: 24745410 DOI: 10.1103/physrevlett.112.132503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Indexed: 06/03/2023]
Abstract
The charge form factor of 4He has been extracted in the range 29 fm(-2) ≤ Q2 ≤ 77 fm(-2) from elastic electron scattering, detecting 4He recoil nuclei and electrons in coincidence with the high resolution spectrometers of the Hall A Facility of Jefferson Lab. The measurements have uncovered a second diffraction minimum for the form factor, which was predicted in the Q2 range of this experiment. The data are in qualitative agreement with theoretical calculations based on realistic interactions and accurate methods to solve the few-body problem.
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Viviani M, Girlanda L, Kievsky A, Marcucci LE. Effect of three-nucleon interactions in p-(3)He elastic scattering. PHYSICAL REVIEW LETTERS 2013; 111:172302. [PMID: 24206480 DOI: 10.1103/physrevlett.111.172302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Indexed: 06/02/2023]
Abstract
We present a detailed study of the effect of different three-nucleon interactions in p-(3)He elastic scattering at low energies. In particular, two interactions have been considered: one derived from effective field theory at next-to-next-to-leading order and one derived from a more phenomenological point of view-the so-called Illinois model. The four-nucleon scattering observables are calculated by using the Kohn variational principle and the hyperspherical harmonics technique, and the results are compared with available experimental data. We have found that the inclusion of both interactions improves the agreement with the experimental data, in particular, for the proton vector analyzing power.
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Marcucci LE, Schiavilla R, Viviani M. Proton-proton weak capture in chiral effective field theory. PHYSICAL REVIEW LETTERS 2013; 110:192503. [PMID: 23705703 DOI: 10.1103/physrevlett.110.192503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Indexed: 06/02/2023]
Abstract
The astrophysical S factor for proton-proton weak capture is calculated in chiral effective field theory over the center-of-mass relative-energy range 0-100 keV. The chiral two-nucleon potential derived up to next-to-next-to-next-to leading order is augmented by the full electromagnetic interaction including, beyond Coulomb, two-photon and vacuum-polarization corrections. The low-energy constants entering the weak current operators are fixed so as to reproduce the A=3 binding energies and magnetic moments and the Gamow-Teller matrix element in tritium β decay. Contributions from S and P partial waves in the incoming two-proton channel are retained. The S factor at zero energy is found to be S(0)=(4.030±0.006)×10(-23) MeV fm(2), with a P-wave contribution of 0.020×10(-23) MeV fm(2). The theoretical uncertainty is due to the fitting procedure of the low-energy constants and to the cutoff dependence.
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Frederico T, Salmè G, Viviani M. Two-body scattering states in Minkowski space and the Nakanishi integral representation onto the null plane. Int J Clin Exp Med 2012. [DOI: 10.1103/physrevd.85.036009] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Marcucci LE, Kievsky A, Rosati S, Schiavilla R, Viviani M. Chiral effective field theory predictions for muon capture on deuteron and {3}He. PHYSICAL REVIEW LETTERS 2012; 108:052502. [PMID: 22400928 DOI: 10.1103/physrevlett.108.052502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Indexed: 05/31/2023]
Abstract
The muon-capture reactions {2}H(μ{-},ν{μ})nn and {3}He(μ{-},ν{μ}){3}H are studied with nuclear potentials and charge-changing weak currents, derived in chiral effective field theory. The low-energy constants (LECs) c{D} and c{E}, present in the three-nucleon potential and (c{D}) axial-vector current, are constrained to reproduce the A=3 binding energies and the triton Gamow-Teller matrix element. The muon-capture rates on deuteron and {3}He are predicted to be 399±3 sec{-1} and 1494±21 sec{-1}, respectively. The spread accounts for the cutoff sensitivity, as well as uncertainties in the LECs and electroweak radiative corrections. By comparing the calculated and precisely measured rates on {3}He, a value for the induced pseudoscalar form factor is obtained in good agreement with the chiral perturbation theory prediction.
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Girlanda L, Kievsky A, Marcucci LE, Pastore S, Schiavilla R, Viviani M. Thermal neutron captures on d and 3He. PHYSICAL REVIEW LETTERS 2010; 105:232502. [PMID: 21231454 DOI: 10.1103/physrevlett.105.232502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Indexed: 05/30/2023]
Abstract
We report on a study of the nd and n(3)He radiative captures at thermal neutron energies, using wave functions obtained from either chiral or conventional two- and three-nucleon realistic potentials with the hyperspherical-harmonics method, and electromagnetic currents derived in chiral effective field theory up to one loop. The predicted nd and n(3)He cross sections are in good agreement with data, but exhibit a significant dependence on the input Hamiltonian. A comparison is also made between these and new results for the nd and n(3)He cross sections obtained in the conventional framework for both potentials and currents.
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Viviani M, Van Saene HKF, Pisa F, Lucangelo U, Silvestri L, Momesso E, Berlot G. The role of admission surveillance cultures in patients requiring prolonged mechanical ventilation in the intensive care unit. Anaesth Intensive Care 2010; 38:325-35. [PMID: 20369767 DOI: 10.1177/0310057x1003800215] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We undertook a prospective observational cohort study in intensive care unit (ICU) patients requiring mechanical ventilation for four days or more to evaluate normal and abnormal bacterial carriage on admission detected by surveillance cultures of throat and rectum. We assessed the importance of surveillance and diagnostic cultures for the early detection of resistance to third generation cephalosporins employed as the parenteral component of the selective decontamination of the digestive tract. Finally, we sought the risk factors of abnormal carriage on admission to the ICU. During the 58-month study 621 patients were included: 186 patients (30%) carried abnormal flora including methicillin-resistant Staphylococcus aureus (MRSA) and aerobic Gram negative bacilli (AGNB) on admission to the ICU Both MRSA and AGNB carriers were more commonly present in the hospital group of patients than in patients referred from the community (P < 0.001), although overgrowth was equally present both in community and in hospital patients. The incidence of infections during ICU stay was higher in abnormal (n=120, 64.5%) than in normal carriers (n=185, 42.5%) (P < 0.0001), with an odds ratio of 2.46 (95% confidence interval 1.72 to 3.51). Third generation cephalosporins covered ICU admission flora in 482 (78%) of the studied population. AGNB resistant to cephalosporins and MRSA were detected in surveillance cultures of 139 patients (22%), while the same resistant micro-organisms were identified only in 49 diagnostic samples (7.9%). Parenteral cephalosporins were modified in patients with abnormal flora (P < 0.0001). One hundred and ninety-six patients received antibiotics before admission to the ICU and 42% carried AGNB resistant to cephalosporins. Previous antibiotic use was the only risk factor for abnormal carriage in the multivariate analysis (OR 3.5; 95% confidence interval 2.1 to 5.8). The knowledge of carriage on admission using surveillance cultures may help intensivists to identify patients with abnormal carriage on admission and resistant bacterial strains at an early stage even when diagnostic samples are negative. Third generation cephalosporins covered admission flora in about 80% of the enrolled population and were modified in patients with abnormal flora who received antibiotic therapy before ICU admission. Our finding of overgrowth present on admission may justify the immediate administration of enteral antimicrobials.
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Viviani M, Girlanda L, Kievsky A, Marcucci L, Rosati S. Proton-3He elastic scattering at low energies and the “AyPuzzle”. EPJ WEB OF CONFERENCES 2010. [DOI: 10.1051/epjconf/20100305011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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