Nuclear Theory·nucl-th

Tuesday·August 7, 2018

10 papers—2 primary·8 cross-listed

03
[Submitted on 3 Aug 2018] (cross-list from hep-ph)
Time-evolution of fluctuations as signal of the phase transition dynamics in a QCD-assisted transport approach
M. Bluhm🇵🇱 · Y. Jiang🇨🇳 · M. Nahrgang🇫🇷 · J.M. Pawlowski🇩🇪 · F. Rennecke🇺🇸 · N. Wink🇩🇪
For the understanding of fluctuation measurements in heavy-ion collisions it is crucial to develop quantitatively reliable dynamical descriptions which take the non-perturbative nature of QCD near the phase transition into account. We discuss a novel QCD-assisted transport approach based on non-equilibrium chiral fluid dynamics and the effective action of low energy QCD. In this framework, we study the time-evolution of fluctuation measures of the critical mode, notably the kurtosis, for a non-expanding system. From this, we can estimate the equilibration times of critical mode fluctuations in the QCD phase diagram. These allow us to identify both the phase boundary and the critical region near the QCD critical point.
Comments:
Quark Matter 2018 Proceedings
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
1808.01377 [pdf]
NPA(2019)·30 citations
04
[Submitted on 4 Aug 2018] (cross-list from hep-ex)
Heavy-ion collisions - hot QCD in a lab
Mateusz Ploskon🇺🇸
High-energy heavy-ion collisions provide a unique opportunity to study the properties of the hot and dense strongly-interacting system composed of deconfined quarks and gluons -- the quark-gluon plasma (QGP) -- in laboratory conditions. The formation of a QGP is predicted by lattice QCD calculations as a crossover transition from hadronic matter (at zero baryochemical potential) and is expected to take place once the system temperature reaches values above 155 MeV and/or the energy density above $0.5 GeV / fm^{3}$ . The nature of such a strongly coupled QGP has been linked to the early Universe at some microseconds after the Big Bang. To characterize the physical properties of the short-lived matter (lifetime of about $10 fm / c$ ) experimental studies at Relativistic Heavy-Ion Collider and the Large Hadron collider use auto-generated probes, such as high-energy partons created early in the hadronic collisions, thermally emitted photons, and a set of particle correlations that are sensitive to the collective expansion and the dynamics of the system. The lectures briefly introduced some of the experimental techniques and provided a glimpse at some of the results.
Comments:
Proceedings of the XIV International Workshop on Hadron Physics, Florianopolis, Brazil, March 2018
Subjects:
High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1808.01411 [pdf]
10 citations
05
[Submitted on 4 Aug 2018] (cross-list from nucl-ex)
Study of relativistic charged particles production in ^{84}Kr$_{36}+Em interaction at around 1 A GeV with wounded nucleon model
N. Marimuthu · V. Singh · S. S. R. Inbanathan
This article is focused on the multiplicity and probability distribution of the emitted charged pions <N_{\pi}> for interaction of ^{84}Kr_{36} projectile with nuclear emulsion targets at kinetic energy 1 GeV per nucleon. In the wounded nucleon model frame work, we have calculated the total number of wounded nucleons (W) and total number of interactions ({\nu}). The obtained results revealed that the average multiplicity of the charged pions <N_{\pi}> is dependent on the projectile and target mass. The calculated values of the wounded nucleons (W) and total number of interactions ({\nu}) shows strong dependence on the mass of the colliding nuclei. The emission rate of mean multiplicity of the <N_{s}> and <N_{\pi}> increases with increasing the total number of wounded nucleons (W) and total number of interactions ({\nu}). The mean multiplicity value of <N_{s}> and <N_{\pi}> linearly increases with increasing the projectile mass number (A_{P}) and independent of the incident energy.
Comments:
17 pages, 10 figures and 3 tables
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1808.01485 [pdf]
IJMPE(2019)·14 citations
06
[Submitted on 6 Aug 2018] (cross-list from nucl-ex)
Measurement of the analyzing powers in pd elastic and pn quasi-elastic scattering at small angles
S.Barsov🇷🇺 · Z.Bagdasarian🇬🇪 · S.Dymov🇷🇺 · R.Gebel🇩🇪 · M.Hartmann🇩🇪 · A.Kacharava🇩🇪 · I.Keshelashvili🇩🇪 · A.Khoukaz🇩🇪 · V.Komarov🇷🇺 · P.Kulessa🇵🇱 · A.Kulikov🇷🇺 · A.Lehrach🇩🇪 and 21 other authors
The analyzing powers in proton-deuteron elastic and proton-neutron quasi-elastic scattering have been measured at small angles using a polarized proton beam at the COSY storage ring incident on an unpolarized deuterium target. The data were taken at 796MeV and five higher energies from 1600MeV to 2400MeV. The analyzing power in pd elastic scattering was studied by detecting the low energy recoil deuteron in telescopes placed symmetrically in the COSY plane to the left and right of the beam whereas for pn quasi-elastic scattering a low energy proton was registered in one of the telescopes in coincidence with a fast scattered proton measured in the ANKE magnetic spectrometer. Though the experiment explores new domains, the results are consistent with the limited published information.
Comments:
10 pages with 8 figures
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1808.01792 [pdf]
EPJA(2018)·3 citations
07
[Submitted on 6 Aug 2018] (cross-list from astro-ph.HE)
Cooling of neutron stars in "nuclear medium cooling scenario" with stiff equation of state including hyperons
Hovik Grigorian🇷🇺 · Dmitry N. Voskresensky🇷🇺 · Konstantin A. Maslov🇷🇺
We demonstrate that the existing neutron-star cooling data can be appropriately described within "the nuclear medium cooling scenario" including hyperons under the assumption that different sources have different masses. We use a stiff equation of state of the relativistic mean-field model MKVORH $ϕ$ with hadron effective couplings and masses dependent on the scalar field. It fulfills a large number of experimental constraints on the equation of state of the nuclear matter including the $2 M_{⊙}$ lower bound for the maximum predicted neutron-star mass and the constraint for the pressure from the heavy-ion particle flow. We select appropriate $^{1} S_{0}$ proton and $Λ$ hyperon pairing gap profiles from those exploited in the literature and allow for a variation of the effective pion gap controlling the efficiency of the medium modified Urca process. The $^{3} P_{2}$ neutron pairing gap is assumed to be negligibly small in our scenario. The possibility of the pion, kaon and charged $ρ$ -meson condensations is for simplicity suppressed. The resulting cooling curves prove to be sensitive to the value and the density dependence of the pp pairing gap and rather insensitive to the values of the $^{1} S_{0}$ neutron pairing gaps.
Comments:
35 pages, 15 figures
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1808.01819 [pdf]
NPA(2018)·23 citations
08
[Submitted on 6 Aug 2018] (cross-list from hep-ph)
Phase diagram of two-color QCD matter at finite baryon and axial isospin densities
Jingyi Chao🇨🇳
We study the two-color QCD matter within two fundamental quark flavors via both chiral perturbation theory and Nambu--Jona-Lasinio model methods. The effective Lagrangian described by low lying meson and baryon, i.e., diquark, is derived, where the excitations locate in the extended $SU (4)$ flavor symmetry space. We determine the leading order terms on the dependence of the baryon and axial isospin densities. Then, the two-color NJL model is employed to run the numerical simulation and the phase diagram in the plane of $μ - ν_{5}$ is plotted.
Comments:
10 pages, 5 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
1808.01928 [pdf]
CPC(2020)·13 citations
09
[Submitted on 6 Aug 2018] (cross-list from hep-ph)
Quark matter under rotation in the NJL model with vector interaction
Xinyang Wang🇨🇳 · Minghua Wei🇨🇳 · Zhibin Li🇨🇳 · Mei Huang🇨🇳
We study the chiral phase transition of quark matter under rotation in two-flavor Nambu--Jona-Lasinio (NJL) model. It is found that, in the rotating frame, the angular velocity plays the similar role as the baryon chemical potential and suppresses the chiral condensate, thus the chiral phase transition shows a critical end point not only in the temperature-chemical potential $T - μ$ plane, but also in the temperature-angular momentum $T - ω$ plane. One interesting observation is that in the $T - μ$ plane, the presence of the angular momentum only shifts down the critical temperature $T^{E}$ of the CEP and does not shift the critical chemical potential $μ^{E}$ , and in the $T - ω$ plane, the increase of the chemical potential only shift down the critical temperature $T^{E}$ and does not change the critical angular momentum $ω^{E}$ . The phase structure in the $T - μ$ plane is sensitive to the coupling strength in the vector channel, while the phase structure in $T - ω$ plane is not. It is also observed that the rotating angular velocity suppresses the kurtosis of the baryon number fluctuations, while it enhances the pressure density, energy density, the specific heat and the sound velocity.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1808.01931 [pdf]
PRD(2019)·109 citations
10
[Submitted on 6 Aug 2018] (cross-list from hep-ph)
Deep Inelastic Scattering on a Nucleus using Holography
Kiminad A. Mamo🇺🇸 · Ismail Zahed🇺🇸
We consider deep inelastic scattering (DIS) on a nucleus described using a density expansion. In leading order, the scattering is dominated by the incoherent scattering on individual nucleons distributed using the Thomas-Fermi approximation. We use the holographic structure functions for DIS scattering on single nucleons to make a non-perturbative estimate of the nuclear structure function in leading order in the density. Our results are compared to the data in the large-x regime.
Comments:
6 pages, 2 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
1808.01952 [pdf]
PRD(2019)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE