Nuclear Theory·nucl-th

Thursday·January 26, 2017

5 papers—2 primary·3 cross-listed

01
One fluid to rule them all: viscous hydrodynamic description of event-by-event central p+p, p+Pb and Pb+Pb collisions at $s = 5.02$ TeV
Ryan D. Weller🇺🇸 · Paul Romatschke🇺🇸
The matter created in central p+p, p+Pb and Pb+Pb collisions at sqrt{s}=5.02 TeV is simulated event-by-event using the superSONIC model, which combines pre-equilibrium flow, viscous hydrodynamic evolution and late-stage hadronic rescatterings. Employing a generalization of the Monte Carlo Glauber model where each nucleon possesses three constituent quarks, superSONIC describes the experimentally measured elliptic and triangular flow at central rapidity in all systems using a single choice for the fluid parameters, such as shear and bulk viscosities. This suggests a common hydrodynamic origin of the experimentally observed flow patterns in all high energy nuclear collisions, including p+p.
nucl-thhep-phnucl-exPLB(2017)·306 citations
02
Spin polarization observables of the deuteron photodisintegration at low energies in pionless effective field theory
Young-Ho Song · Shung-Ichi Ando · Chang Ho Hyun
Spin polarization observables of the deuteron photodisintegration at low energies are studied in a pionless effective field theory up to next-to-next-to-leading order (NNLO). The total and differential cross sections, induced neutron polarization $P_{y^{'}}$ , and tensor analyzing powers $T_{20}$ and $T_{22}$ of the process are calculated at photon energies from the breakup threshold to 20~MeV. We find that the NNLO corrections in the cross sections and $P_{y^{'}}$ converge well whereas they turn out to be important contributions in $T_{20}$ and $T_{22}$ . We discuss the discrepancy between theory and experiment in $P_{y^{'}}$ still persisting as well as an implication of our result to the first measurement of $T_{20}$ at low energies in the HIGS facility.
nucl-thnucl-exPRC(2017)·7 citations
03
Novel scenario for production of heavy flavored mesons in heavy ion collisions
B.Z. Kopeliovich🇨🇱 · J. Nemchik🇸🇰 · I.K. Potashnikova🇨🇱 · Ivan Schmidt🇨🇱
The observed strong suppression of heavy flavored hadrons produced with high $p_{T}$ , is caused by final state interactions with the created dense medium. Vacuum radiation of high-pT heavy quarks ceases at a short time scale, as is confirmed by pQCD calculations and by LEP measurements of the fragmentation functions of heavy quarks. Production of a heavy flavored hadrons in a dense medium is considerably delayed due to prompt breakup of the hadrons by the medium. This causes a strong suppression of the heavy quark yield because of the specific shape of the fragmentation function. The parameter-free description is in a good accord with available data.
↳ hep-phnucl-thEPJ Web Conf.(2017)·6 citations
04
Flavor analysis of nucleon, $Δ$ , and hyperon electromagnetic form factors
Martin Rohrmoser🇫🇷 · Ki-Seok Choi🇰🇷 · Willibald Plessas🇦🇹
By the analysis of the world data base of elastic electron scattering on the proton and the neutron (for the latter, in fact, on $^{2} H$ and $^{3} H e$ ) important experimental insights have recently been gained into the flavor compositions of nucleon electromagnetic form factors. We report on testing the Graz Goldstone-boson-exchange relativistic constituent-quark model in comparison to the flavor contents in low-energy nucleons, as revealed from electron-scattering phenomenology. It is found that a satisfactory agreement is achieved between theory and experiment for momentum transfers up to $Q^{2} \sim$ 4 GeV $^{2}$ , relying on three-quark configurations only. Analogous studies have been extended to the $Δ$ and the hyperon electromagnetic form factors. For them we here show only some sample results in comparison to data from lattice quantum chromodynamics.
↳ hep-phnucl-thFew Body Syst.(2017)·1 citation
05
Quark Deconfinement in Rotating Neutron Stars
R. D. Mellinger🇺🇸 · F. Weber🇺🇸 · W. Spinella🇺🇸 · G. A. Contrera🇺🇸 · M. G. Orsaria🇦🇷
In this paper, we use a three flavor non-local Nambu--Jona-Lasinio (NJL) model, an~improved effective model of Quantum Chromodynamics (QCD) at low energies, to investigate the existence of deconfined quarks in the cores of neutron stars. Particular emphasis is put on the possible existence of quark matter in the cores of rotating neutron stars (pulsars). In contrast to non-rotating neutron stars, whose particle compositions do not change with time (are frozen in), the type and structure of the matter in the cores of rotating neutron stars depends on the spin frequencies of these stars, which opens up a possible new window on the nature of matter deep in the cores of neutron stars. Our study shows that, depending on mass and rotational frequency, up to around 8% of the mass of a massive neutron star may be in the mixed quark-hadron phase, if the phase transition is treated as a Gibbs transition. We also find that the gravitational mass at which quark deconfinement occurs in rotating neutron stars varies quadratically with spin frequency, which can be fitted by a simple formula.
↳ astro-ph.HEhep-phnucl-thUniverse(2017)·21 citations

Affiliations

first authorsco-authorsvia INSPIRE

One fluid to rule them all: viscous hydrodynamic description of event-by-event central p+p, p+Pb and Pb+Pb collisions at s​=5.02 TeV

Spin polarization observables of the deuteron photodisintegration at low energies in pionless effective field theory

Novel scenario for production of heavy flavored mesons in heavy ion collisions

Flavor analysis of nucleon, Δ, and hyperon electromagnetic form factors

Quark Deconfinement in Rotating Neutron Stars

Affiliations

One fluid to rule them all: viscous hydrodynamic description of event-by-event central p+p, p+Pb and Pb+Pb collisions at $s = 5.02$ TeV

Flavor analysis of nucleon, $Δ$ , and hyperon electromagnetic form factors