Nuclear Theory·nucl-th

Friday·July 24, 2015

10 papers—5 primary·5 cross-listed

06
Energy loss, equilibration, and thermodynamics of a baryon rich strongly coupled quark-gluon plasma
Romulo Rougemont (Sao Paulo U.)🇧🇷 · Andrej Ficnar (Oxford U., Theor. Phys.)🇬🇧 · Stefano Finazzo (Sao Paulo U. & Sao Paulo, IFT)🇧🇷 · Jorge Noronha (Sao Paulo U. & Columbia U.)🇺🇸
Lattice data for the QCD equation of state and the baryon susceptibility near the crossover phase transition (at zero baryon density) are used to determine the input parameters of a 5-dimensional Einstein-Maxwell-Dilaton holographic model that provides a consistent holographic framework to study both equilibrium and out-of-equilibrium properties of a hot and {\it baryon rich} strongly coupled quark-gluon plasma (QGP). We compare our holographic equation of state computed at nonzero baryon chemical potential, $μ_{B}$ , with recent lattice calculations and find quantitative agreement for the pressure and the speed of sound for $μ_{B} \leq 400$ MeV. This holographic model is used to obtain holographic predictions for the temperature and $μ_{B}$ dependence of the drag force and the Langevin diffusion coefficients associated with heavy quark jet propagation as well as the jet quenching parameter $q^$ and the shooting string energy loss of light quarks in the baryon dense plasma. We find that the energy loss of heavy and light quarks generally displays a nontrivial, fast-varying behavior as a function of the temperature near the crossover. Moreover, energy loss is also found to generally increase due to nonzero baryon density effects even though this strongly coupled liquid cannot be described in terms of well defined quasiparticle excitations. Furthermore, to get a glimpse of how thermalization occurs in a hot and baryon dense QGP, we study how the lowest quasinormal mode of an external massless scalar disturbance in the bulk is affected by a nonzero baryon charge. We find that the equilibration time associated with the lowest quasinormal mode decreases in a dense medium.
↳ hep-thhep-phnucl-thJHEP(2016)·107 citations
07
Forward Heavy Quarkonium Productions at the LHC
Kazuhiro Watanabe🇨🇳 · Bo-Wen Xiao🇨🇳
We investigate the low transverse momentum heavy quarkonium ( $J / ψ$ , $Υ$ ) productions in the forward rapidity region of $pp$ and $p A$ collisions at the LHC as an important probe to the transverse momentum tomography of the gluons in hadrons in the Color Glass Condensate (CGC) framework. By implementing the Sudakov resummation consistently in the CGC formalism, we achieve an excellent agreement between the improved CGC calculations and the LHC data. We show that both the small- $x$ and the Sudakov effects are essential for a complete description of heavy quarkonium productions in the low transverse momentum region. This provides a solid foundation to study the small- $x$ gluon saturation in a big nucleus with the future $p A$ programs at the LHC.
↳ hep-phnucl-thPRD(2015)·22 citations
08
Photon production from a non-equilibrium quark-gluon plasma
Lusaka Bhattacharya🇺🇸 · Radoslaw Ryblewski🇵🇱 · Michael Strickland🇺🇸
We calculate leading-order medium photon yields from a quark-gluon plasma using (3+1)-dimensional anisotropic hydrodynamics. Non-equilibrium corrections to the photon rate are taken into account using a self-consistent modification of the particle distribution functions and the corresponding anisotropic hard-loop fermionic self-energies. We present predictions for the high-energy photon spectrum and photon elliptic flow as a function of transverse momentum, shear viscosity, and initial momentum-space anisotropy. Our findings indicate that high-energy photon production is sensitive to the assumed level of initial momentum-space anisotropy of the quark-gluon plasma. As a result, it may be possible to experimentally constrain the early-time momentum-space anisotropy of the quark-gluon plasma generated in relativistic heavy-ion collisions using high-energy photon yields.
↳ hep-phnucl-thPRD(2016)·41 citations
09
The resonant $π^{+} γ \to π^{+} π^{0}$ amplitude from Quantum Chromodynamics
Raul A. Briceno🇺🇸 · Jozef J. Dudek🇺🇸 · Robert G. Edwards🇺🇸 · Christian J. Shultz🇺🇸 · Christopher E. Thomas🇬🇧 · David J. Wilson🇺🇸
We present the first ab initio calculation of a radiative transition of a hadronic resonance within quantum chromodynamics (QCD). We compute the amplitude for $π π \to π γ^{⋆}$ , as a function of the energy of the $π π$ pair and the virtuality of the photon, in the kinematic regime where $π π$ couples strongly to the unstable $ρ$ resonance. This exploratory calculation is performed using a lattice discretization of QCD with quark masses corresponding to $m_{π} \approx 400$ ~MeV. We obtain a description of the energy dependence of the transition amplitude, constrained at 48 kinematic points, that we can analytically continue to the $ρ$ pole and identify from its residue the $ρ \to π γ^{⋆}$ form factor.
↳ hep-phhep-latnucl-thPRL(2015)·105 citations
10
Diagonal and off-diagonal quark number susceptibilities at high temperatures
H.-T. Ding🇨🇳 · Swagato Mukherjee🇺🇸 · H. Ohno🇺🇸 · P. Petreczky🇺🇸 · H.-P. Schadler🇺🇸
We present continuum extrapolated lattice QCD results for up to fourth-order diagonal and off-diagonal quark number susceptibilities in the high temperature region of 300-700 MeV. Lattice QCD calculations are performed using 2+1 flavors of highly improved staggered quarks with nearly physical quark masses and at four different lattice spacings. Comparisons of our results with recent weak coupling perturbative calculations yield reasonably good agreements for the entire temperature range.
↳ hep-lathep-phnucl-thPRD(2015)·126 citations

Affiliations

first authorsco-authorsvia INSPIRE

Energy loss, equilibration, and thermodynamics of a baryon rich strongly coupled quark-gluon plasma

Forward Heavy Quarkonium Productions at the LHC

Photon production from a non-equilibrium quark-gluon plasma

The resonant π+γ→π+π0 amplitude from Quantum Chromodynamics

Diagonal and off-diagonal quark number susceptibilities at high temperatures

Affiliations

The resonant $π^{+} γ \to π^{+} π^{0}$ amplitude from Quantum Chromodynamics