Work-life balance: a comparison of women in cardiology and other specialties

OBJECTIVE

Significant gender disparities exist in some medical specialties, particularly cardiology. We assessed work, personal life and work-life balance in women in cardiology in Australia and New Zealand (NZ), compared with other specialties, to determine factors that may contribute to the lack of women in the specialty.

METHODS

This study is a prospective survey-based cohort study comparing cardiology and non-cardiology specialties. An online survey was completed by female doctors in Australia and NZ, recruited via email lists and relevant social media groups. The survey included demographics, specialty, stage of training, work hours/setting, children and relationships, career satisfaction, income and perceptions of specialty.

RESULTS

452 participants completed the survey (median age 36 years), of which 57 (13%) worked in cardiology. Of all respondents, 84% were partnered and 75% had children, with no difference between cardiology and non-cardiology specialties. Compared with non-cardiology specialties, women in cardiology worked more hours per week (median 50 hours vs 40 hours, p<0.001), were more likely to be on call more than once per week (33% vs 12%, p<0.001) and were more likely to earn an annual income >$3 00 000 (35% vs 10%, p<0.001). Women in cardiology were less likely to agree that they led a balanced life (33% vs 51%, p=0.03) or that their specialty was female friendly (19% vs 75%, p<0.001) or family friendly (20% vs 63%, p<0.001).

CONCLUSIONS

Compared with other specialties, women in cardiology reported poorer work-life balance, greater hours worked and on-call commitments and were less likely to perceive their specialty as female friendly or family friendly. Addressing work-life balance may attract and retain more women in cardiology.

Comparison of Long-Term Outcomes After Percutaneous Coronary Intervention in Patients With Insulin-Treated Versus Non-Insulin Treated Diabetes Mellitus

There are conflicting data on whether patients with insulin-treated diabetes mellitus (ITDM) have poorer outcomes compared with non-insulin treated diabetic (non-ITDM) patients following percutaneous coronary intervention (PCI). We therefore compared clinical outcomes following PCI in ITDM versus non-ITDM patients. We prospectively collected data on 4,579 patients with diabetes underwent PCI between 2005 and 2014 in a large multicenter registry and dichotomized them as having ITDM (n = 1,111) or non-ITDM (n = 3,468). The non-ITDM group was further divided into diet control only (diet-DM; n = 786) and those taking oral hypoglycemic agents (OHG-DM; n = 2,639), and clinical outcomes were compared with ITDM patients. Median follow-up for long-term mortality was 4.2 years (IQR 2.0 to 6.6 years). ITDM patients were more likely to be female, obese, and have severe renal impairment (all p <0.001). Procedural characteristics were similar other than a greater use of drug-eluting stents in ITDM patients. On multivariable analysis, ITDM was an independent predictor of 12-month major adverse cardiovascular and cerebrovascular events (MACCE; OR 1.26, 95% CI 1.02 to1.55, p = 0.03). Dividing the non-ITDM group further by treatment, a progressively higher rate of 12-month MACCE across the 3 groups was observed (13.5% vs 17.9% vs 21.8%; p <0.001). Long-term mortality was similar in the diet-DM and OHG-DM groups, but significantly higher in the ITDM group on Kaplan-Meier analysis (log-rank p <0.001). In conclusion, there is a clear gradient of adverse outcomes with escalation of therapy from diet control to OHGs to insulin.

Elliptic Flow of Electrons from Beauty-Hadron Decays in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

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.

Cosmic ray flux and lockdown due to COVID-19 in Kolkata - Any correlation?

Cosmic ray muon flux is measured by the coincidence technique using plastic scintillation detectors in the High Energy Physics Detector Laboratory at Bose Institute, Kolkata. Due to the COVID-19 outbreak and nationwide complete lockdown, the laboratory was closed from the end of March 2020 till the end of May 2020. After lockdown, although the city is not in its normal state, we still were able to take data on some days. The lockdown imposed a strict restriction on the transport service other than the emergency ones and also most of the industries were shut down in and around the city. This lockdown has significant effect on the atmospheric conditions in terms of change in the concentration of air pollutants. We have measured the cosmic ray flux before and after the lockdown to observe the apparent change if any, due to change in the atmospheric conditions. In this article, we report the measured cosmic ray flux at Kolkata (22.58∘ N 88.42∘ E and 11 m above the Sea Level) along with the major air pollutants present in the atmosphere before and after the lockdown.

New ^{59}Fe Stellar Decay Rate with Implications for the ^{60}Fe Radioactivity in Massive Stars

The discrepancy between observations from γ-ray astronomy of the ^{60}Fe/^{26}Al γ-ray flux ratio and recent calculations is an unresolved puzzle in nuclear astrophysics. The stellar β-decay rate of ^{59}Fe is one of the major nuclear uncertainties impeding us from a precise prediction. The important Gamow-Teller strengths from the low-lying states in ^{59}Fe to the ^{59}Co ground state are measured for the first time using the exclusive measurement of the ^{59}Co(t,^{3}He+γ)^{59}Fe charge-exchange reaction. The new stellar decay rate of ^{59}Fe is a factor of 3.5±1.1 larger than the currently adopted rate at T=1.2  GK. Stellar evolution calculations show that the ^{60}Fe production yield of an 18 solar mass star is decreased significantly by 40% when using the new rate. Our result eliminates one of the major nuclear uncertainties in the predicted yield of ^{60}Fe and alleviates the existing discrepancy of the ^{60}Fe/^{26}Al ratio.

Experimental Evidence for Common Driving Effects in Low-Energy Fission from Sublead to Actinides

Isotopic distributions of fragments from fission of the neutron-deficient ^{178}Hg nuclide are reported. This experimental observable is obtained for the first time in the region around lead using an innovative approach based on inverse kinematics and the coincidence between the large acceptance magnetic spectrometer VAMOS++ and a new detection arm close to the target. The average fragment N/Z ratio and prompt neutron M_{n} multiplicity are derived and compared with current knowledge from actinide fission. A striking consistency emerges, revealing the unexpected dominant role of the proton subsystem with atomic number between the Z=28 and 50 magic numbers. The origin of nuclear charge polarization in fission and fragment deformation at scission are discussed.

Gender equity within medical specialties of Australia and New Zealand: cardiology's outlier status

BACKGROUND

Gender disparity remains a prominent medical workforce issue, extending beyond surgical specialties with low proportions of female doctors.

AIMS

To examine female representation within Australia and New Zealand (NZ) among physician specialties and certain comparator surgical specialties with a focus on cardiology as an outlier of workforce gender equality.

METHODS

Data of practising medical specialists, new consultants and trainees were sought from the Australian Health Practitioner Regulation Agency, the Medical Council of NZ and the Royal Australasian College of Surgeons (2015-2017). The stratified data pertaining to interventional cardiologists were obtained through direct contact with individual hospitals (from 2017 to 2018) and derived from state-based cardiac registries.

RESULTS

In Australia and NZ, there were fewer female practising adult medicine physician consultants (n = 8956, 32%, P < 0.001), with gender disparities seen across most physician specialties. Cardiology (15%) was the only physician specialty with <20% representation; gastroenterology (23%), neurology (27%) and respiratory medicine (29%) had <30% female representation at the consultant level. The rates of cardiology (15%) and interventional cardiology (5%) were similar to general surgery (15%) and orthopaedics (4%). Although more than half of physician trainees are female, and most physician specialties are approaching or have equal gender ratios at the trainee level, cardiology (23%) and interventional cardiology (9%) remain significantly underrepresented.

CONCLUSIONS

Cardiology is the only physician specialty with <20% female consultants, and this disparity is reflected throughout every stage of the cardiology training programme. Increased awareness and proactive strategies are needed to improve gender disparity within this underrepresented medical specialty.

Anomalous Quantum Oscillations in a Heterostructure of Graphene on a Proximate Quantum Spin Liquid

The quasi-two-dimensional Mott insulator α-RuCl_{3} is proximate to the sought-after Kitaev quantum spin liquid (QSL). In a layer of α-RuCl_{3} on graphene, the dominant Kitaev exchange is further enhanced by strain. Recently, quantum oscillation (QO) measurements of such α-RuCl_{3} and graphene heterostructures showed an anomalous temperature dependence beyond the standard Lifshitz-Kosevich (LK) description. Here, we develop a theory of anomalous QO in an effective Kitaev-Kondo lattice model in which the itinerant electrons of the graphene layer interact with the correlated magnetic layer via spin interactions. At low temperatures, a heavy Fermi liquid emerges such that the neutral Majorana fermion excitations of the Kitaev QSL acquire charge by hybridizing with the graphene Dirac band. Using ab initio calculations to determine the parameters of our low-energy model, we provide a microscopic theory of anomalous QOs with a non-LK temperature dependence consistent with our measurements. We show how remnants of fractionalized spin excitations can give rise to characteristic signatures in QO experiments.

Markers of Cardiovascular Disease among Adults Exposed to Smoke from the Hazelwood Coal Mine Fire

Little research has examined the effects of high concentration, medium-duration smoke exposure on cardiovascular health. We investigated whether six weeks of exposure to smoke from the 2014 Hazelwood coal mine fire in Victoria (Australia), was associated with long-term clinical or subclinical cardiovascular disease approximately four years later, in adult residents of the towns of Morwell (exposed, n = 336) and Sale (unexposed, n = 162). The primary outcome was serum high sensitivity (hs) C-reactive protein (CRP). Blood pressure, electrocardiogram, flow mediated dilatation and serum levels of hs-troponin, N-terminal pro B-type natriuretic peptide and lipids were secondary outcomes. There was no significant difference in weighted median hsCRP levels between exposed and unexposed participants (1.9 mg/L vs. 1.6 mg/L, p = 0.273). Other outcomes were comparable between the groups. hsCRP was associated in a predictable manner with current smoking, obesity and use of lipid-lowering therapy. Four years after a 6-week coal mine fire, this study found no association between smoke exposure and markers of clinical or subclinical cardiovascular disease in exposed adults.

Effect of Age on Clinical Outcomes in Elderly Patients (>80 Years) Undergoing Percutaneous Coronary Intervention: Insights From a Multi-Centre Australian PCI Registry

OBJECTIVES

To evaluate the effect of age in an all-comers population undergoing percutaneous coronary intervention (PCI).

BACKGROUND

Age is an important consideration in determining appropriateness for invasive cardiac assessment and perceived clinical outcomes.

METHODS

We analysed data from 29,012 consecutive patients undergoing PCI in the Melbourne Interventional Group (MIG) registry between 2005 and 2017. 25,730 patients <80 year old (78% male, mean age 62±10 years; non-elderly cohort) were compared to 3,282 patients ≥80 year old (61% male, mean age 84±3 years; elderly cohort).

RESULTS

The elderly cohort had greater prevalence of hypertension, diabetes and previous myocardial infarction (all p<0.001). Elderly patients were more likely to present with acute coronary syndromes, left ventricular ejection fraction <45% and chronic kidney disease (p<0.0001). In-hospital, 30-day and long-term all-cause mortality (over a median of 3.6 and 5.1 years for elderly and non-elderly cohorts, respectively) were higher in the elderly cohort (5.2% vs. 1.9%; 6.4% vs. 2.2%; and 43% vs. 14% respectively, all p<0.0001). In multivariate Cox regression analysis, estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m² (HR 3.8, 95% CI: 3.4-4.3), cardiogenic shock (HR 3.0, 95% CI: 2.6-3.4), ejection fraction <30% (HR 2.5, 95% CI: 2.1-2.9); and age ≥80 years (HR 2.8, 95% CI: 2.6-3.1) were independent predictors of long-term all-cause mortality (all p<0.0001).

CONCLUSION

The elderly cohort is a high-risk group of patients with increasing age being associated with poorer long-term mortality. Age, thus, should be an important consideration when individualising treatment in elderly patients.

Photoresponse of CdSe-PVA nanocomposite films at low magnetic fields

A set of nanocomposite films of poly-vinyl alcohol (PVA) and 0.1-0.4 wt% CdSe nanoparticles (NPs) were developed by spin coating and their surface resistance (R) was measured as a function of light illumination intensity (I_L ) and applied magnetic field (H). The ferromagnetic CdSe NPs were synthesized by a facile chemical method which ensured in situ surface stabilization with a skinny layer of graphitic carbon. The CdSe NPs were uniformly dispersed in an aqueous solution of 2.0 wt% PVA and spin-coated on fluorine-doped tin oxide coated glass substrates. The photoresponse of the nanocomposite films at low H exhibits their efficacy for pertinent applications in optoelectronics.

National cardiac registries: a systematic review

Background

Over the last thirty years, there has been exponential growth in the number and scale of national cardiovascular disease registries. We aimed to provide a comprehensive outline of contemporary national cardiac registries across all subspecialties.

Methods

We performed a systematic literature review by searching OvidMedline in August 2019 to identify registries relating to six pre-specified domains (Table). For inclusion, registries had to be national in nature, actively collecting data, and publishing either peer-reviewed publications or online reports.

Results

A total of 24,076 records were identified from six domain-specific Medline searches; 24,057 abstracts were screened with 19,435 non-relevant records excluded; 4,624 full texts were screened with 4,473 non-relevant texts excluded; and 151 registries met inclusion criteria representing 51 countries. Of these, 15 related to cardiac surgery, 27 to arrhythmia (17 device, 5 ablation, 7 atrial fibrillation), 21 to congenital heart disease (14 general, 2 interventional, 4 surgical, and 1 disease specific), 43 to coronary disease or percutaneous coronary intervention (22 PCI, 21 CAD), 27 to heart failure (13 heart failure, 5 transplant, 2 mechanical support, 7 disease specific), and 18 related to structural intervention (3 any, 13 transcatheter aortic valve replacement, 2 mitral intervention). Nine national registries (USA, Sweden, Finland, Denmark, UK, Portugal, Norway, Taiwan, and Singapore) covered multiple domains. Quality scoring using the Monash University Clinical Quality Registry Grading System (a composite score of recruitment, and data completeness, definitions, reliability and validation), demonstrated marked heterogeneity in quality between registries.

Conclusions

Cardiac registries have seen rapid growth, however the use and quality among various subspecialties differs markedly across world regions. Given the multiple benefits, clinicians, funders and health bureaucrats should be encouraged to focus on the range, quality and uptake of national registries.

Figure 1

Funding Acknowledgement

Type of funding source: None

Incidence, causes and predictors of unplanned hospital readmission after percutaneous coronary intervention

Background

Unplanned hospital readmissions post-percutaneous coronary intervention (PCI) result in a significant burden to the healthcare system and adverse patient outcomes. Understanding factors associated with 30-day readmission rates may help to reduce this burden. Data linkage of clinical quality registry data with routinely collected administrative datasets may assist in overcoming resource constraints that limit collection of follow-up data but is currently under-utilised worldwide.

Objective

To determine the incidence of, and factors associated with unplanned hospital readmissions in the first 30 days following PCI.

Methods

We prospectively collected data on 28,488 patients undergoing PCI between January 2013 and December 2018, who were enrolled in a multi-centre PCI registry. Data linkage to government administrative datasets was used to determine whether patients had an unplanned readmission within 30 days of PCI, the number of admissions prior to PCI and primary reason for readmission (as recorded by the International Classification of Diseases, 10th revision, Australian modification (ICD-10-AM) diagnosis codes). Patients were then divided into 3 groups: those who had 1 or more unplanned readmissions for primarily cardiac issues, those who those who had 1 or more unplanned readmissions for primarily non-cardiac issues, and those who were not readmitted, and compared for baseline, procedural and in-hospital care characteristics.

Results

In total, 3,059 patients (10.7%) had an unplanned hospital readmission within 30 days of PCI, of which, 1,848 patients (60.4%) were readmitted for primarily cardiac diagnoses. Independent predictors of both 30-day cardiac and non-cardiac readmissions were female sex, having &gt;1 admission in the 12 months prior to PCI, acute coronary syndrome presentation, having any in-hospital complication and being discharged on an oral anticoagulant (all p&lt;0.05). A stepwise increase in readmission risk was observed with increasing number of admissions from 1 to &gt;4 admissions in the 12 months prior to PCI. Presentation with cardiogenic shock (p=0.04), having an unsuccessful PCI (p=0.02) and left ventricular systolic dysfunction (p=0.02) were independent predictors of cardiac readmissions but not non-cardiac readmissions. Conversely, age &gt;60 years (p&lt;0.001) and history of diabetes mellitus (p=0.02) were found to be independent predictors of non-cardiac readmissions only.

Conclusion

Thirty-day unplanned hospital readmissions after PCI pose a significant burden to the health system. Most readmissions are primarily due to cardiac diagnoses. The most important predictive factor for both cardiac and non-cardiac readmissions appears to be the number of hospital admissions in the 12 months prior to PCI. This is valuable information for health administrators as treatment and discharge policies, and outpatient follow-up timetables may need to be tailored to patients at high risk for readmission following PCI.

Causes of readmission post-PCI

Funding Acknowledgement

Type of funding source: None

Measurement of the Low-Energy Antideuteron Inelastic Cross Section

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.

Incidence and Predictors of Unplanned Hospital Readmission after Percutaneous Coronary Intervention

Unplanned readmissions to hospital after percutaneous coronary intervention (PCI) pose a significant burden to the healthcare system and are potentially preventable. In this study, we sought to determine the incidence of, and risk factors for, unplanned hospital readmissions within 30 days following PCI. We prospectively collected data on 28,488 patients undergoing PCI between 2013 and 2019, who were enrolled in the state-wide multi-centre Victorian Cardiac Outcomes Registry. Patients’ data were then linked to data from the Victorian Department of Health administrative database that records statewide hospital admissions. Disease diagnosis codes were used to identify cause of readmission. Patients who had an unplanned readmission were further divided into those who had a cardiac vs. non-cardiac cause for readmission. Overall, 3059 patients (10.7%) had an unplanned hospital readmission within 30 days of PCI, of which 1848 patients (60.4%) were readmitted for primarily cardiac diagnoses. Independent predictors of both 30-day unplanned cardiac and non-cardiac readmissions post-PCI were female sex, having ≥1 admission in the 12 months prior to PCI, acute coronary syndrome presentation, having any in-hospital complication and being discharged on an oral anticoagulant (all p < 0.05). A stepwise increase in readmission risk was observed with increasing number of admissions from 1 to ≥4 admissions in the 12 months prior to PCI. In conclusion, a substantial proportion of patients undergoing PCI have unexpected readmissions to hospital in the 30 days following PCI. Targeted strategies for patients with risk factors for readmission may be useful to reduce this significant burden to the healthcare system.

Clinical outcomes following ST-elevation myocardial infarction secondary to stent thrombosis treated by percutaneous coronary intervention

OBJECTIVES

To assess the clinical outcomes of patients presenting with ST-elevation myocardial infarction (STEMI) secondary to stent thrombosis (ST) compared to those presenting with STEMI secondary to a de novo culprit lesion and treated by percutaneous coronary intervention (PCI).

BACKGROUND

ST is an infrequent but serious complication of PCI with substantial associated morbidity and mortality, however with limited data.

METHODS

We studied consecutive patients who underwent PCI for STEMI from 2005 to 2013 enrolled prospectively in the Melbourne Interventional Group registry. Patients were divided into two groups: the ST group comprised patients where the STEMI was due to ST and the de novo group formed the remainder of the STEMI cohort and all patients were treated by PCI. The primary endpoint was 30-day all-cause mortality.

RESULTS

Compared to the de novo group (n = 3,835), the ST group (n = 128; 3.2% of STEMI) had higher rates of diabetes, hypertension and dyslipidemia, established cardiovascular diseases, myocardial infarction, and peripheral vascular disease, all p < .01. Within the ST group, very-late ST was the most common form of ST, followed by late and early ST (64, 19, and 17%, respectively). There was no significant difference in the primary outcome between the ST group and the de novo group (4.7 vs. 7.1%, p = .29). On multivariate analysis, ST was not an independent predictor of 30-day mortality (odds ratio: 0.62, 95% confidence interval: 0.07-1.09, p = .068).

CONCLUSION

The short-term prognosis of patients with STEMI secondary to ST who were treated by PCI was comparable to that of patients with STEMI due to de novo lesions.

Probing the Effects of Strong Electromagnetic Fields with Charge-Dependent Directed Flow in Pb-Pb Collisions at the LHC

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.

Evidence of Spin-Orbital Angular Momentum Interactions in Relativistic Heavy-Ion Collisions

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.

Scattering Studies with Low-Energy Kaon-Proton Femtoscopy in Proton-Proton Collisions at the LHC

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.