Nuclear Theory·nucl-th

Friday·January 22, 2016

11 papers—7 primary·4 cross-listed

08
Specific Heat of Matter Formed in Relativistic Nuclear Collisions
Sumit Basu🇮🇳 · Sandeep Chatterjee🇮🇳 · Rupa Chatterjee🇮🇳 · Tapan K. Nayak🇮🇳 · Basanta K. Nandi🇮🇳
We report the excitation energy dependence of specific heat (\cv) of hadronic matter at freeze-out in Au+Au and Cu+Cu collisions at the Relativistic Heavy Ion Collider energies by analyzing the published data on event-by-event mean transverse momentum (\meanpt) distributions. The \meanpt~distributions in finite \pt~ranges are converted to distributions of effective temperatures, and dynamical fluctuations in temperature are extracted by subtracting widths of the corresponding mixed event distributions. The heat capacity per particle at the kinetic freeze-out surface is presented as a function of collision energy, which shows a sharp rise in \cv~below \sNN~=~62.4~GeV. We employ the Hadron Resonance Gas (HRG) model to estimate \cv~at the chemical and kinetic freeze-out surfaces. The experimental results are compared to the HRG and other theoretical model calculations. HRG results show good agreement with data. Model predictions for \cv~at the Large Hadron Collider energy are presented.
↳ nucl-exhep-phnucl-thPRC(2016)·37 citations
09
Charmonia in a Contact Interaction
Marco A. Bedolla🇲🇽 · J.J. Cobos-Martínez🇲🇽 · Adnan Bashir🇲🇽
For the flavour-singlet heavy quark system of charmonia, we compute the masses of the ground state mesons in four different channels: pseudo-scalar ( $η_{c} (1 S)$ ), vector ( $J /Ψ (1 S)$ ), scalar ( $χ_{c_{0}} (1 P)$ ) and axial vector ( $χ_{c_{1}} (1 P)$ ), as well as the weak decay constants of the $η_{c} (1 S)$ and $J /Ψ (1 S)$ and the charge radius of $η_{c} (1 S)$ . The framework for this analysis is provided by a symmetry-preserving Schwinger-Dyson equation (SDEs) treatment of a vector $\times$ vector contact interaction (CI). The results found for the meson masses and the weak decay constants, for the spin-spin combinations studied, are in fairly good agreement with experimental data and earlier model calculations based upon Schwinger-Dyson and Bethe-Salpeter equations (BSEs) involving sophisticated interaction kernels. The charge radius of $η_{c} (1 S)$ is consistent with the results from refined SDE studies and lattice Quantum Chromodynamics (QCD).
↳ hep-phnucl-thPRD(2015)·58 citations
10
Phase diagram and nucleation in the Polyakov-loop-extended Quark-Meson truncation of QCD with the unquenched Polyakov-loop potential
Rainer Stiele🇫🇷 · Juergen Schaffner-Bielich🇩🇪
Unquenching of the Polyakov-loop potential showed to be an important improvement for the description of the phase structure and thermodynamics of strongly-interacting matter at zero quark chemical potentials with Polyakov-loop extended chiral models. This work constitutes the first application of the quark backreaction on the Polyakov-loop potential at nonzero density. The observation is that it links the chiral and deconfinement phase transition also at small temperatures and large quark chemical potentials. The build up of the surface tension in the Polyakov-loop extended Quark-Meson model is explored by investigating the two and 2+1-flavour Quark-Meson model and analysing the impact of the Polyakov-loop extension. In general, the order of magnitude of the surface tension is given by the chiral phase transition. The coupling of the chiral and deconfinement transition with the unquenched Polyakov-loop potential leads to the fact that the Polyakov-loop contributes at all temperatures.
↳ hep-phnucl-thPRD(2016)·32 citations
11
Nonperturbative True Muonium on the Light Front with TMSWIFT
Henry Lamm🇺🇸 · Richard F. Lebed🇺🇸
The true muonium $(μ μ ˉ)$ bound state presents an interesting test of light-cone quantization techniques. In addition to exhibiting the standard problems of handling non-perturbative calculations, true muonium requires correct treatment of $e e ˉ$ Fock-state contributions. Having previously produced a crude model of true muonium using the method of iterated resolvents, our current work has focused on the inclusion of the box diagrams to improve the cutoff-dependent issues of the model. Further, a parallel computer code, TMSWIFT, allowing for smaller numerical uncertainties, has been developed. This work focuses on the current state of these efforts to develop a model of true muonium that is testable at near-term experiments.
↳ hep-phnucl-thphysics.comp-phFew Body Syst.(2016)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE

Specific Heat of Matter Formed in Relativistic Nuclear Collisions

Charmonia in a Contact Interaction

Phase diagram and nucleation in the Polyakov-loop-extended Quark-Meson truncation of QCD with the unquenched Polyakov-loop potential

Nonperturbative True Muonium on the Light Front with TMSWIFT

Affiliations