Wed·Nov 10, 2021Wednesday·November 10, 2021

1. 01*

   Fluctuations and correlations in nucleus-nucleus collisions observed by NA61/SHINE at CERN SPS energies

   Maja Maćkowiak-Pawłowska (for the NA61/SHINE Collaboration)🇵🇱

   The NA61/SHINE strong interaction programme aims to explore the phase diagram of the strongly interacting matter. The main physics goals are the study of the onset of deconfinement and the search for the critical point of the strongly interacting matter. These goals are pursued by performing a scan in beam momentum (13A -- 158A GeV/c) and size of colliding system (p+p, p+Pb, Be+Be, Ar+Sc, Xe+La, Pb+Pb). This contribution presents new results on system size and energy dependence of multiplicity and net-charge fluctuations measured with higher-order moments of these distributions. Also, new results on the measurement of Bose-Einstein correlations in nucleus-nucleus collisions based on Levy sources are discussed as well as news on anisotropic flow in Pb+Pb interactions at 13A GeV/c.

   nucl-exPoS(2022)·2 citations
2. 02*

   High-precision $Q$-value measurement and nuclear matrix elements for the double-$\beta$ decay of ${}^{98}$Mo

   D.A. Nesterenko🇫🇮 · L. Jokiniemi🇪🇸 · J. Kotila🇫🇮 · A. Kankainen🇫🇮 · Z. Ge🇫🇮 · T. Eronen🇫🇮 · S. Rinta-Antila🇫🇮 · J. Suhonen🇫🇮

   Neutrinoless double-beta ($0\nu \beta \beta$) decay and the standard two-neutrino double-beta ($2\nu \beta \beta$) decay of ${}^{98}$Mo have been studied. The double-beta decay $Q$-value has been determined as $Q_{\beta \beta }=113.668(68)$ keV using the JYFLTRAP Penning trap mass spectrometer. It is in agreement with the literature value, $Q_{\beta \beta }=109(6)$ keV, but almost 90 times more precise. Based on the measured $Q$-value, precise phase-space factors for $2\nu \beta \beta$ decay and $0\nu \beta \beta$ decay, needed in the half-life predictions, have been calculated. Furthermore, the involved nuclear matrix elements have been computed in the proton-neutron quasiparticle random-phase approximation (pnQRPA) and the microscopic interacting boson model (IBM-2) frameworks. Finally, predictions for the $2\nu \beta \beta$ decay are given, suggesting a much longer half-life than for the currently observed cases.

   nucl-exnucl-thEPJA(2022)·7 citations
3. 03*

   Collective dynamics of heavy ion collisions in ATLAS

   Helena Santos (on behalf of the ATLAS Collaboration)🇵🇹

   The latest measurements of collective behaviour in a variety of collision systems with the ATLAS detector at the LHC, including pp collisions at 13 TeV, Xe+Xe collisions at 5.44 TeV, and Pb+Pb collisions at 5.02 TeV, are presented. They include vn-[pT] correlations, which carry important information about the initial-state geometry of the quark-gluon plasma and can shed light on any quadrupole deformation in the Xe nucleus, and measurements of flow decorrelations differential in rapidity, which probe the longitudinal structure of the colliding system. These measurements furthermore provide stringent tests of the theoretical understanding of the initial state in heavy ion collisions.

   nucl-exhep-exSciPost Phys.Proc.(2022)·0 citations
4. 04*

   Coupled-channel analysis of pion- and eta-electroproduction with the Jülich-Bonn-Washington model

   Maxim Mai🇺🇸 · Michael Döring🇺🇸 · Carlos Granados🇺🇸 · Helmut Haberzettl🇺🇸 · Jackson Hergenrather🇺🇸 · Ulf-G. Meißner🇩🇪 · Deborah Rönchen🇩🇪 · Igor Strakovsky🇺🇸 · Ron Workman🇺🇸

   Pion and eta electroproduction data are jointly analyzed for the first time, up to a center-of-mass energy of 1.6 GeV. The framework is a dynamical coupled-channel model, based on the recent Jülich-Bonn-Washington analysis of pion electroproduction data for the same energy range. Comparisons are made to a number of single-channel eta electroproduction fits. By comparing multipoles of comparable fit quality, we find some of these amplitudes are well determined over the near-threshold region, while others will require fits over an extended energy range.

   ↳ nucl-thhep-phnucl-exPRC(2022)·31 citations
5. 05*

   Pairing dynamics and solitonic excitations in collisions of medium-mass, identical nuclei

   Piotr Magierski🇵🇱 · Andrzej Makowski · Matthew C. Barton · Kazuyuki Sekizawa🇯🇵 · Gabriel Wlazłowski🇺🇸

   We present results of collisions of ${}^{90}$Zr+${}^{90}$Zr and ${}^{96}$Zr+${}^{96}$Zr obtained within time-dependent density functional theory (TDDFT) extended to superfluid systems, known as time-dependent superfluid local density approximation (TDSLDA). We discuss qualitatively new features occurring in collisions of two superfluid nuclei at energies in the vicinity of the Coulomb barrier. We show that a \textit{solitonic excitation} -- an abrupt pairing phase distortion -- reported previously [P.~Magierski et al., Phys. Rev. Lett. \textbf{119}, 042501 (2017)], increases the barrier for capture generating effective repulsion between colliding nuclei. Moreover we demonstrate that pairing field leads to qualitatively different dynamics at the Coulomb barrier which manifests itself in a slower evolution of deformation towards a compact shape. Last but not least, we show that magnitude of pairing correlations can be dynamically enhanced after collision. We interpret it as a dynamically induced $U(1)$ symmetry breaking, which leads to large-amplitude oscillations of pairing field and bear similarity to the pairing Higgs mechanism.

   ↳ nucl-thcond-mat.quant-gascond-mat.supr-connucl-exPRC(2022)·14 citations
6. 06*

   Exploring the effect of hadron cascade-time on particle production in Xe+Xe collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.44 TeV through a multi-phase transport model

   Girija Sankar Pradhan🇮🇳 · Rutuparna Rath🇮🇳 · Ronald Scaria🇮🇳 · Raghunath Sahoo🇮🇳

   Heavy-ion collisions at ultra-relativistic energies provide extreme conditions of energy density and temperature to produce a deconfined state of quarks and gluons. Xenon (Xe) being a deformed nucleus further gives access to the effect of initial geometry on final state particle production. This study focuses on the effect of nuclear deformation and hadron cascade-time on the particle production and elliptic flow using A Multi-Phase Transport (AMPT) model in Xe+Xe collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.44 TeV. We explore the effect of hadronic cascade-time on identified particle production through the study of $p_{\mathrm{T}}$-differential particle ratios. The effect of hadronic cascade-time on the generation of elliptic flow is studied by varying the cascade-time between 5 and 25 fm/$c$. This study shows the final state interactions among particles generate additional anisotropic flow with increasing hadron cascade-time, especially at very low and high-$p_{\mathrm{T}}$.

   ↳ hep-phhep-exnucl-exnucl-thPRC(2022)·9 citations
7. 07*

   Testing Lepton Flavor Universality with Pion, Kaon, Tau, and Beta Decays

   Douglas Bryman🇨🇦 · Vincenzo Cirigliano🇺🇸 · Andreas Crivellin🇨🇭 · Gianluca Inguglia🇦🇹

   We present an overview of searches fo violation of lepton flavor universality with focus on low energy precision probes using pions, kaons, tau leptons, and nuclear beta decays. The current experimental results are reviewed, the theoretical status within the context of the Standard Model is summarized, and future prospects (both experimental and theoretical) are discussed. We review the implications of these measurements for physics beyond the Standard Model by performing a global model-independent fit to modified $W$ couplings to leptons and four-fermion operators. We also discuss new physics in the context of simplified models and review Standard Model extensions with focus on those which can explain a possible deviation from unitarity of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.

   ↳ hep-phhep-exhep-latnucl-ex+1Ann.Rev.Nucl.Part.Sci.(2022)·71 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.