Nuclear Theory·nucl-th

Tuesday·May 19, 2015

10 papers—4 primary·6 cross-listed

05
[Submitted on 16 May 2015] (cross-list from hep-ph)
Flow harmonics $v_{n}$ at finite density
Yoshitaka Hatta🇯🇵 · Akihiko Monnai🇺🇸 · Bo-Wen Xiao🇨🇳
We generalize the Gubser solution of viscous hydrodynamics by including the finite density effect and analytically compute the flow harmonics $v_{n}$ . We explicitly show how $v_{n}$ and their viscous corrections depend on the chemical potential. The difference in $v_{n}$ between particles and antiparticles is also analytically computed and shown to be proportional to various chemical potentials and the viscosity. Excellent agreement is obtained between the results and the available experimental data from the SPS, RHIC and the LHC.
Comments:
30 pages, 5 figures; v2: figures revised, discussion added, to be published in PRD
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1505.04226 [pdf]
PRD(2015)·31 citations
06
[Submitted on 18 May 2015] (cross-list from hep-ph)
Implication of the observed $ψ (3770) \to p p ˉ π^{0}$ for studying the $p p ˉ \to ψ (3770) π^{0}$ process
Hao Xu🇨🇳 · Ju-Jun Xie🇨🇳 · Xiang Liu🇨🇳
We study the charmonium $p p ˉ \to ψ (3770) π^{0}$ reaction using the effective lagrangian approach where the contributions from well established $N^{*}$ states are considered, and all parameters are fixed in the process of $e^{+} e^{-} \to p p ˉ π^{0}$ at center of mass energy $s = 3.773$ GeV. The experimental data on the line shape of the mass distribution of the $e^{+} e^{-} \to p p ˉ π^{0}$ can be well reproduced. Based on the studying of $e^{+} e^{-} \to p p ˉ π^{0}$ , the total and differential cross sections of the $p p ˉ \to ψ (3770) π^{0}$ reaction are predicted. At the same time we evaluated also the cross sections of the $p p ˉ \to ψ (3686) π^{0}$ reaction. It is shown that the contribution of the nucleon pole to this reaction is largest from the reaction threshold within a wide range. However, the interference between nucleon pole and the other nucleon resonance can still change the angle distributions significantly. Those theoretical results may be test by the future experiments at $\mbox P$ ANDA.
Comments:
8 pages, 10 figures, and 4 tables. Accepted by Eur. Phys. J. C. updated some results according to an erratum
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1505.04571 [pdf]
EPJC(2016)·14 citations
07
[Submitted on 18 May 2015] (cross-list from hep-ph)
Entropy production in quantum Yang-Mills mechanics in semi-classical approximation
Hidekazu Tsukiji🇯🇵 · Hideaki Iida🇯🇵 · Teiji Kunihiro🇯🇵 · Akira Ohnishi🇯🇵 · Toru T. Takahashi🇯🇵
We discuss thermalization of isolated quantum systems by using the Husimi-Wehrl entropy evaluated in the semiclassical treatment. The Husimi-Wehrl entropy is the Wehrl entropy obtained by using the Husimi function for the phase space distribution. The time evolution of the Husimi function is given by smearing the Wigner function, whose time evolution is obtained in the semiclassical approximation. We show the efficiency and usefullness of this semiclassical treatment in describing entropy production of a couple of quantum mechanical systems, whose classical counter systems are known to be chaotic. We propose two methods to evaluate the time evolution of the Husimi-Wehrl entropy, the test-particle method and the two-step Monte-Carlo method. We demonstrate the characteristics of the two methods by numerical calculations, and show that the simultaneous application of the two methods ensures the reliability of the results of the Husimi-Wehrl entropy at a given time.
Comments:
11 pages, 8 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
1505.04698 [pdf]
PTEP(2015)·5 citations
08
[Submitted on 18 May 2015] (cross-list from nucl-ex)
Interpretations of Elastic Electron Scattering
T.W. Donnelly🇺🇸 · D.K. Hasell🇺🇸 · R.G. Milner🇺🇸
Elastic scattering of relativistic electrons from the nucleon yields Lorentz invariant form factors that describe the fundamental distribution of charge and magnetism. The spatial dependence of the nucleon's charge and magnetism is typically interpreted in the Breit reference frame which is related by a Lorentz boost from the laboratory frame, where the nucleon is at rest. We construct a toy model to estimate how the charge and magnetic radii of the nucleon are modified between the Breit and lab. frames. This has implications for the ratio of the proton electric to magnetic elastic form factors as a function of momentum transfer as well as for determinations of the proton charge radius. Predicted corrections based on the model are provided for the rms charge radii of the deuteron, the triton, and the helium isotopes.
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1505.04723 [pdf]
3 citations
09
[Submitted on 18 May 2015] (cross-list from hep-ph)
Monte-Carlo approach to particle-field interactions and the kinetics of the chiral phase transition
Carsten Greiner🇩🇪 · Christian Wesp🇩🇪 · Hendrik van Hees🇩🇪 · Alex Meistrenko🇩🇪
The kinetics of the chiral phase transition is studied within a linear quark-meson- $σ$ model, using a Monte-Carlo approach to semiclassical particle-field dynamics. The meson fields are described on the mean-field level and quarks and antiquarks as ensembles of test particles. Collisions between quarks and antiquarks as well as the $q q$ annihilation to $σ$ mesons and the decay of $σ$ mesons is treated, using the corresponding transition-matrix elements from the underlying quantum field theory, obeying strictly the rule of detailed balance and energy-momentum conservation. The approach allows to study fluctuations without making ad hoc assumptions concerning the statistical nature of the random process as necessary in Langevin-Fokker-Planck frameworks.
Comments:
7 pages, 7 figures, contribution to the proceedings of the 31st Winter Workshop on Nuclear Dynamics 2015
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1505.04738 [pdf]
J.Phys.Conf.Ser.(2015)·5 citations
10
[Submitted on 18 May 2015] (cross-list from hep-ph)
Thermodynamics of an exactly solvable confining quark model
M. S. Guimaraes🇧🇷 · B. W. Mintz🇧🇷 · L. F. Palhares🇧🇷
The grand partition function of a model of confined quarks is exactly calculated at arbitrary temperatures and quark chemical potentials. The model is inspired by a softly BRST-broken version of QCD and possesses a quark mass function compatible with nonperturbative analyses of lattice simulations and Dyson-Schwinger equations. Even though the model is defined at tree level, we show that it produces a nontrivial and stable thermodynamic behaviour at any temperature or chemical potential. Results for the pressure, the entropy and the trace anomaly as a function of the temperature are qualitatively compatible with the effect of nonperturbative interactions as observed in lattice simulations. The finite density thermodynamics is also shown to contain nontrivial features, being far away from an ideal gas picture.
Comments:
17 pages, 7 figures. v2: 19 pages, 10 figures, extended results section, matches PRD version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
1505.04760 [pdf]
PRD(2015)·16 citations

Affiliations

first authorsco-authorsvia INSPIRE

Flow harmonics vn​ at finite density

Implication of the observed ψ(3770)→ppˉ​π0 for studying the ppˉ​→ψ(3770)π0 process

Entropy production in quantum Yang-Mills mechanics in semi-classical approximation

Interpretations of Elastic Electron Scattering

Monte-Carlo approach to particle-field interactions and the kinetics of the chiral phase transition

Thermodynamics of an exactly solvable confining quark model

Affiliations

Flow harmonics $v_{n}$ at finite density

Implication of the observed $ψ (3770) \to p p ˉ π^{0}$ for studying the $p p ˉ \to ψ (3770) π^{0}$ process