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Nuclear Theory·nucl-th

Thursday·April 4, 2019

11 papers—6 primary·5 cross-listed

All11Primary6Cross-lists5
  1. 07

    Nuclear correlations and modifications of the nucleon-nucleon potential due to the QCD critical mode

    Juan M. Torres-Rincon🇺🇸 · Edward Shuryak🇺🇸

    The scalar-isoscalar mode of QCD becomes lighter/nearly massless close to the chiral transition/second-order critical point. From nuclear physics we know that this mode is the main responsible for the attractive part of the nucleon-nucleon potential at inter-particle distances of 1-2 fm. Therefore one expects that close to the critical point there is a long-range strong attraction among nucleons. Using a Walecka-Serot model for the NN potential we study the effects of the critical point in a finite system of nucleons and mesons by solving classical Molecular Dynamics+Langevin equations for the freeze-out conditions of heavy-ion collisions. Going beyond the mean-field approximation allows us to account for strong nucleon correlations in the time evolution, leading to baryon clustering. We observe that light cluster formation, together with an enhancement of higher-order cumulants of the proton distribution can signal the presence of the critical point.

    ↳ hep-phnucl-thPoS(2019)·1 citation
  2. 08

    On the convergence of chiral expansions for charmed meson masses in the up, down and strange quark masses

    Matthias F.M. Lutz🇩🇪 · Xiao-Yu Guo🇩🇪 · Yonggoo Heo🇹🇭

    We discuss the convergence properties of chiral expansions for the pseudoscalar and vector charmed meson masses based on the chiral SU(3) Lagrangian. Conventional expansion strategies as formulated in terms of bare meson masses are shown to suffer from poor convergence properties. This changes once the expansion is set up in terms of on-shell masses. We find a rapid convergence of the chiral expansion from vanishing quark masses up to physical values of the strange quark mass in this case. Detailed results are presented at the one-loop level for the D-meson and D^*-meson masses. It is emphasized that our results do not depend on the renormalization scale. An approximation hierarchy for the chiral Ward identities of QCD is obtained that keeps the proper form of low-energy branch points and cuts as they are implied by the use of on-shell masses. Given such a scheme we analyzed the charmed meson masses as available on various QCD lattice ensembles. In terms of the determined low-energy constants we consider the coupled-channel interactions of the Goldstone bosons with open-charm mesons. For the isospin violating hadronic decay width of the D_{s0}^*(2317) we predict the range (104-116) keV.

    ↳ hep-phnucl-thPoS(2019)·0 citations
  3. 09

    Anomalous magnetohydrodynamics with longitudinal boost invariance and chiral magnetic effect

    Irfan Siddique🇨🇳 · Ren-jie Wang🇨🇳 · Shi Pu🇨🇳 · Qun Wang🇨🇳

    We study relativistic magnetohydrodynamics with longitudinal boost invariance in the presence of chiral magnetic effects and finite electric conductivity. With initial magnetic fields parallel or anti-parallel to electric fields, we derive the analytic solutions of electromagnetic fields and the chiral number and energy density in an expansion of several parameters determined by initial conditions. The numerical solutions show that such analytic solutions work well in weak fields or large chiral fluctuations. We also discuss the properties of electromagnetic fields in the laboratory frame.

    ↳ hep-phnucl-thPRD(2019)·40 citations
  4. 10

    QCD-like phase diagram with Efimov trimers and Cooper pairs in resonantly interacting SU(3) Fermi gases

    Hiroyuki Tajima🇯🇵 · Pascal Naidon🇯🇵

    We investigate color superfluidity and trimer formation in resonantly interacting SU(3) Fermi gases with a finite interaction range. The finite range is crucial to avoid the Thomas collapse and treat the Efimov effect occurring in this system. Using the Skorniakov-Ter-Martirosian (STM) equation with medium effects, we show the effects of the atomic Fermi distribution on the Efimov trimer energy at finite temperature. We show the critical temperature of color superfluidity within the non-selfconsistent -matrix approximation (TMA). In this way, we can provide a first insight into the phase diagram as a function of the temperature and the chemical potential . This phase diagram consists of trimer, normal, and color-superfluid phases, and is similar to that of quantum chromodynamics (QCD) at finite density and temperature, indicating a possibility to simulate the properties of such extremely dense matter in the laboratory.

    ↳ cond-mat.quant-gascond-mat.supr-conhep-thnucl-thNew J.Phys.(2019)·12 citations
  5. 11

    Reliable estimation of the radius of convergence in finite density QCD

    Matteo Giordano🇭🇺 · Attila Pásztor🇭🇺

    We study different estimators of the radius of convergence of the Taylor series of the pressure in finite density QCD. We adopt the approach in which the radius of convergence is estimated first in a finite volume, and the infinite-volume limit is taken later. This requires an estimator for the radius of convergence that is reliable in a finite volume. Based on general arguments about the analytic structure of the partition function in a finite volume, we demonstrate that the ratio estimator cannot work in this approach, and propose three new estimators, capable of extracting reliably the radius of convergence, which coincides with the distance from the origin of the closest Lee-Yang zero. We also provide an estimator for the phase of the closest Lee-Yang zero, necessary to assess whether the leading singularity is a true critical point. We demonstrate the usage of these estimators on a toy model, namely 4 flavors of unimproved staggered fermions on a small lattice, where both the radius of convergence and the Taylor coefficients to any order can be obtained by a direct determination of the Lee-Yang zeros. Interestingly, while the relative statistical error of the Taylor expansion coefficients steadily grows with order, that of our estimators stabilizes, allowing for an accurate estimate of the radius of convergence. In particular, we show that despite the more than 100\% error bars on high-order Taylor coefficients, the given ensemble contains enough information about the radius of convergence.

    ↳ hep-latcond-mat.stat-mechhep-phnucl-thPRD(2019)·48 citations

Affiliations

first authorsco-authorsvia INSPIRE