Wed·Sep 1, 2021Wednesday·September 1, 2021

1. 01*

   First-order Phase Transition and Resulted Expansion in Momentum Space

   Feng Li🇨🇳

   We point out, according to the principle of entropy growth, that the volume occupied by the system in the momentum space should expand during the first-order phase transition. Such an expansion is visualized by the simulation using the transport model based on a NJL-typed Lagrangian, and quantified by several observables, some of which, proposed for the first time in this article, could be the probes of the first-order phase transition either between the quark gluon plasma and the hadronic phase taking place in the heavy-ion collisions or of the other expanding systems.

   ↳ nucl-thnucl-ex0 citations
2. 02*

   Charm and beauty in the deconfined plasma from quenched lattice QCD

   Heng-Tong Ding🇨🇳 · Olaf Kaczmarek🇩🇪 · Anna-Lena Lorenz🇩🇪 · Hiroshi Ohno🇯🇵 · Hauke Sandmeyer🇩🇪 · Hai-Tao Shu🇩🇪

   We present continuum extrapolated results of charmonium and bottomonium correlators in the vector channel at several temperatures below and above $T_c$. The continuum extrapolation jointly performed with the interpolations to have physical values of $J/\psi$ and ${\rm Y}$ masses in the confined phase is based on calculations on several large quenched isotropic lattices using clover-improved Wilson valence fermions carrying different quark masses. The extrapolated lattice correlators are confronted with perturbation theory results incorporating resummed thermal effects around the threshold from pNRQCD and vacuum asymptotics above the threshold. An additional transport peak is modelled below the threshold allowing for an estimate of the diffusion coefficients for charm and bottom quarks. We find that charmonium correlators in the vector channel can be well reproduced by perturbative spectral functions above $T_c$ where no resonance peaks for $J/\psi$ are needed at and above 1.1 $T_c$, while for bottomonium correlators a resonance peak for ${\rm Y}$ is still needed up to 1.5 $T_c$. By analyzing the transport contribution to the correlators we find that the drag coefficient of a charm quark is larger than that of a bottom quark.

   ↳ hep-lathep-phnucl-exnucl-thPRD(2021)·16 citations
3. 03*

   Three-body optical potentials in $(d,p)$ reactions and their influence on indirect study of stellar nucleosynthesis

   M. J. Dinmore · N.K. Timofeyuk🇬🇧 · J.S. Al-Khalili🇬🇧

   Model uncertainties, arising due to suppression of target excitations in the description of deuteron scattering and resulting in a modification of the two-body interactions in a three-body system, are investigated for several $(d,p)$ reactions serving as indirect tools for studying the astrophysical $(p,\gamma )$ reactions relevant to $rp$-process. The three-body nature of deuteron-target potential is treated within adiabatic distorted wave approximation (ADWA) which relies on dominant contribution from the components of the three-body deuteron-target wave function with small $n$-$p$ separations. This results in a simple prescription for treating the explicit energy-dependence of two-body optical potentials in a three-body system requiring nucleon optical potentials to be evaluated at a shifted energy with respect to the standard value of half the deuteron incident energy. In addition, the ADWA allows for leading-order multiple scattering effects to be estimated, which leads to a simple renormalization of the adiabatic potential's imaginary part by the factor of two. These effects are assessed using both nonlocal and local optical potential systematics for ${}^{26}$Al, ${}^{30}$P, ${}^{34}$Cl and ${}^{56}$Ni targets at deuteron incident energy of 12 MeV typical for experiments with radioactive beams in inverse kinematics. The model uncertainties induced by the three-body nature of deuteron-target scattering are found to be within 40$\%$ both in the main peak of angular distributions and in total $(d,p)$ cross sections. At higher deuteron energies, around 60 MeV, model uncertainties can reach 100\% in the total cross sections. A few examples of application to astrophysically interesting proton resonances in ${}^{27}$Si and ${}^{57}$Cu obtained using $(d,p)$ reactions and mirror symmetry are given.

   ↳ nucl-thnucl-exPRC(2021)·2 citations
4. 04*

   The BEST framework for the search for the QCD critical point and the chiral magnetic effect

   Xin An🇺🇸 · Marcus Bluhm🇫🇷 · Lipei Du🇺🇸 · Gerald V. Dunne🇺🇸 · Hannah Elfner🇩🇪 · Charles Gale🇨🇦 · Joaquin Grefa🇺🇸 · Ulrich Heinz🇺🇸 · Anping Huang🇺🇸 · Jamie M. Karthein🇺🇸 · Dmitri E. Kharzeev🇺🇸 · Volker Koch🇺🇸 and 31 other authors

   The Beam Energy Scan Theory (BEST) Collaboration was formed with the goal of providing a theoretical framework for analyzing data from the Beam Energy Scan (BES) program at the relativistic heavy ion collider (RHIC) at Brookhaven National Laboratory. The physics goal of the BES program is the search for a conjectured QCD critical point as well as for manifestations of the chiral magnetic effect. We describe progress that has been made over the previous five years. This includes studies of the equation of state and equilibrium susceptibilities, the development of suitable initial state models, progress in constructing a hydrodynamic framework that includes fluctuations and anomalous transport effects, as well as the development of freezeout prescriptions and hadronic transport models. Finally, we address the challenge of integrating these components into a complete analysis framework. This document describes the collective effort of the BEST Collaboration and its collaborators around the world.

   ↳ nucl-thhep-lathep-phnucl-exNPA(2022)·153 citations
5. 05*

   Spin Physics at COSY (2021-2024 and beyond) -- Pathfinder investigations toward an EDM storage ring and Spin-for-FAIR

   R. Gebel🇩🇪 · V. Hejny🇩🇪 · A. Kacharava🇩🇪 · A. Lehrach🇩🇪 · P. Lenisa🇮🇹 · A. Nass🇩🇪 · J. Pretz🇩🇪 · F. Rathmann🇩🇪 · H. Ströher🇩🇪 · I. Keshelashvili🇩🇪 · E.J. Stephenson🇺🇸 · A. Wrońska Y. Filatov and 15 other authors

   The unique global feature of COSY is its ability to accelerate, store and manipulate polarized proton and deuteron beams. In the recent past, these beams have been used primarily for precision measurements, in particular in connection with the study of charged particle EDMs (Electric Dipole Moment) in storage rings. The role of COSY as a R&D facility and for initial (static and oscillating) EDM measurements can hardly be overestimated. Unfortunately, as a consequence of the strategic decisions of Forschungszentrum Jülich and the subsequent "TransFAIR" agreement between FZJ and GSI Darmstadt, it is currently planned to stop the operation of COSY by the end of 2024. The various groups working with polarized beams at COSY felt it important to collect information on essential measurements to be performed until the termination of machine operation. These experiments, briefly described in this document along with an estimate of the beam time required, serve as pathfinder investigations toward an EDM storage ring and Spin for FAIR.

   ↳ physics.acc-phnucl-ex1 citation

* 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.