Nuclear Theory·nucl-th

Monday·February 3, 2020

5 papers—2 primary·3 cross-listed

01
Radial distribution of charm quarks in jets in high-energy heavy-ion collisions
Sa Wang🇨🇳 · Wei Dai🇨🇳 · Jun Yan🇨🇳 · Ben-Wei Zhang🇨🇳 · Enke Wang🇨🇳
Heavy flavor physics in high-energy heavy-ion collisions is a promising and active area to study the mass dependence of the "jet quenching" effects both at the RHIC and the LHC. In this talk, we present the first theoretical study on the $D^{0}$ meson radial distributions relative to the jet axis both in p+p and Pb+Pb collisions at $s_{N N} = 5.02$ TeV, where a nice agreement of our results with experimental data is observed. The in-medium parton propagations are described by a Monte Carlo transport model which uses the next-to-leading order (NLO) plus parton shower (PS) event generator SHERPA as input and includes elastic (collisional) and inelastic (radiative) in-medium interaction of heavy flavor jet. We find that, at low $D^{0}$ meson $p_{T}$ , the radial distribution significantly shifts to larger radius indicating a strong diffusion effect, and the diffusion effects decrease quickly with $p_{T}$ ,which is consistent with the recent CMS measurements. We demonstrate that the angular deviation of charm quarks is sensitive to $D_{s}$ but not $q^$ , which may provide new constrains on the collisional and radiative heavy quark energy loss.
nucl-thhep-phNPA(2021)·11 citations
02
Studying QGP with flow: A theory overview
Chun Shen🇺🇸
I review recent developments in the phenomenological study of the quark-gluon plasma (QGP) transport properties based on a personal selection of results that were presented at Quark Matter 2019. The constraints on the temperature dependence of QGP shear and bulk viscosity are summarized. I discuss new theory advancements towards more realistic 3D dynamical simulations of heavy-ion collisions at finite baryon density. The challenges and opportunities of applying hydrodynamics to small collision systems are highlighted.
nucl-thhep-phnucl-exNPA(2021)·50 citations
03
Pre-critical soft photons emission from quark matter
B.O. Kerbikov🇷🇺
We compute the soft real photon emission rate from the QCD matter in the vicinity of the critical line at moderate density and the temperature approaching the critical one from above. The obtained production rate exhibits a steep rise close to $T_{c}$ due to the formation of the slow fluctuation mode.
↳ hep-phnucl-thPRD(2020)·2 citations
04
Momentum and its affiliated transport coefficients for a hot QCD matter in a strong magnetic field
Shubhalaxmi Rath🇮🇳 · Binoy Krishna Patra🇮🇳
We have studied the effects of anisotropies on the momentum transport in a QCD matter by shear ( $η$ ) and bulk ( $ζ$ ) viscosities. The anisotropies arise either by the strong magnetic field or by the preferential expansion. This study helps to understand the fluidity and location of transition point of matter through $η / s$ and $ζ / s$ ( $s$ is entropy density), respectively, the sound attenuation through the Prandtl number (Pl), the nature of flow by the Reynolds number (Rl), and the competition between momentum and charge diffusions. The viscosities are calculated in the relaxation time approximation of kinetic theory within the quasiparticle model. Compared to isotropic medium, both $η$ and $ζ$ get increased in magnetic field-driven (B-driven) anisotropy, contrary to the decrease in expansion-driven anisotropy. $η$ increases with temperature faster in former case than in latter case whereas $ζ$ in former case decreases with temperature and in latter case, it is meagre and diminishes at a specific temperature. So the viscosities can distinguish aforesaid anisotropies. Thus, $η / s$ gets enhanced in former case and in latter case, it becomes smaller than isotropic one. Similarly $ζ / s$ gets amplified but decreases faster with the temperature in a strong magnetic field. The Prandtl number gets increased in B-induced anisotropy and gets decreased in expansion-induced anisotropy, compared to isotropic one. Since, Pl is found larger than 1, the sound attenuation is governed by momentum diffusion. The B-driven anisotropy makes the Reynolds number smaller than one, whereas the expansion-driven anisotropy makes it larger. The ratio ( $\frac{η}{s} / \frac{σ _{el}}{T}$ ) gets amplified in B-driven anisotropy whereas it gets reduced in expansion-driven anisotropy. Since, the ratio is always more than one, the momentum diffusion prevails over the charge diffusion.
↳ hep-phhep-thnucl-thPRD(2020)·25 citations
05
Impact of a thermal medium on $D$ mesons and their chiral partners
Glòria Montaña🇪🇸 · Àngels Ramos🇪🇸 · Laura Tolos🇩🇪 · Juan M. Torres-Rincon🇩🇪
We study $D$ and $D_{s}$ mesons at finite temperature using an effective field theory based on chiral and heavy-quark spin-flavor symmetries within the imaginary-time formalism. Interactions with the light degrees of freedom are unitarized via a Bethe-Salpeter approach, and the $D$ and $D_{s}$ self-energies are calculated self-consistently. We generate dynamically the $D_{0}^{*} (2300)$ and $D_{s} (2317)$ states, and study their possible identification as the chiral partners of the $D$ and $D_{s}$ ground states, respectively. We show the evolution of their masses and decay widths as functions of temperature, and provide an analysis of the chiral-symmetry restoration in the heavy-flavor sector below the transition temperature. In particular, we analyse the very special case of the $D$ -meson, for which the chiral partner is associated to the double-pole structure of the $D_{0}^{*} (2300)$ .
↳ hep-phnucl-thPLB(2020)·43 citations

Affiliations

first authorsco-authorsvia INSPIRE

Radial distribution of charm quarks in jets in high-energy heavy-ion collisions

Studying QGP with flow: A theory overview

Pre-critical soft photons emission from quark matter

Momentum and its affiliated transport coefficients for a hot QCD matter in a strong magnetic field

Impact of a thermal medium on D mesons and their chiral partners

Affiliations

Impact of a thermal medium on $D$ mesons and their chiral partners