Nuclear Theory·nucl-th

Monday·April 26, 2021

7 papers—3 primary·4 cross-listed

01
[Submitted on 23 Apr 2021]
Correspondence between momentum dependent relaxation time and field redefinition of relativistic hydrodynamic theory
Sukanya Mitra🇮🇳
In this article a correspondence has been established between the out of equilibrium system dissipation and the thermodynamic field redefinition of the macroscopic variables through the momentum dependent relaxation time approximation (MDRTA) solution of relativistic transport equation. Here, it has been shown that the out of equilibrium thermodynamic fields are not uniquely defined and are subjected to include dissipative effects from the medium. A second order relativistic hydrodynamic theory has been developed including such dissipative effects. The necessary conditions for developing a hydrodynamic theory has been fulfilled, (i) the thermodynamic identities incorporating such redefined fields have been shown to conserve the energy-momentum tensor perfectly under MDRTA, (ii) the non-negativity of entropy production remains unaffected by the inclusion of such dissipative contributions in hydro fields as long as the independent transport coefficients remain positive.
Comments:
Accepted in Physical Review C
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2104.11380 [pdf]
PRC(2022)·6 citations
02
[Submitted on 23 Apr 2021]
Low-energy dipole excitations in $^{20}$ O with antisymmetrized molecular dynamics
Yuki Shikata🇯🇵 · Yoshiko Kanada-En'yo🇯🇵
Low-energy dipole (LED) excitations in $^{20}$ O were investigated by variation after $K$ -projection of deformation( $β$ )-constraint antisymmetrized molecular dynamics combined with the generator coordinate method. We obtained two LED states, namely, the $1_{1}^{-}$ state with one-proton excitation on the relatively weak deformation and the $1_{2}^{-}$ state with a parity asymmetric structure of the normal deformation. The former is characterized by a toroidal dipole (TD) mode with vortical nuclear current, whereas the latter is associated with a low-energy $E 1$ mode caused by surface neutron oscillation along the prolate deformation. The TD (vortical) and $E 1$ modes separately appear as the $K^{π} = 1^{-}$ and $K^{π} = 0^{-}$ components of the deformed states, respectively, but couple with each other in the $1_{1}^{-}$ and $1_{2}^{-}$ states of $^{20}$ O because of $K$ -mixing, and shape fluctuation. As a result of the mixing, TD and $E 1$ transition strengths are fragmented into the $1_{1}^{-}$ and $1_{2}^{-}$ states. We also obtained the $K^{π} = 0^{+}$ , $K^{π} = 0^{-}$ , and $K^{π} = 1^{-}$ bands with cluster structures in the energy region higher than the LED states.
Comments:
12 pages, 15 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2104.11400 [pdf]
PRC(2021)·1 citation
03
[Submitted on 23 Apr 2021]
Intermittency analysis of proton numbers in heavy-ion collisions at energies available at the BNL Relativistic Heavy Ion Collider
Jin Wu🇨🇳 · Yufu Lin🇨🇳 · Zhiming Li🇨🇳 · Xiaofeng Luo🇨🇳 · Yuanfang Wu🇨🇳
Local density fluctuations near the QCD critical point has been suggested to exhibit a power-law behavior which can be probed by an intermittency analysis on scaled factorial moment (SFM) in relativistic heavy-ion collisions. The collision energy and centrality dependence of the second-order SFMs are systematically investigated in Au $+$ Au collisions at $s_{N N}$ = 7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV within the UrQMD model. We estimate the noncritical background in the measurement of intermittency and propose a cumulative variable method to effectively remove the background contributions. We further study the effect of particle detection efficiency by implementing the RHIC (STAR) experimental tracking efficiencies in the UrQMD events. A cell-by-cell method is proposed for experimental application of efficiency corrections on SFM. This work can provide a guidance of background subtraction and efficiency correction for the experimental measurement of intermittency in the search of the QCD critical point in heavy-ion collisions.
Comments:
Replaced with the published version
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2104.11524 [pdf]
PRC(2021)·20 citations
04
[Submitted on 23 Apr 2021] (cross-list from hep-ph)
Dilepton production from magnetized quark matter with an anomalous magnetic moment of the quarks using a three-flavor PNJL model
Nilanjan Chaudhuri🇮🇳 · Snigdha Ghosh🇮🇳 · Sourav Sarkar🇮🇳 · Pradip Roy🇮🇳
Dilepton production from hot, dense and magnetized quark matter is studied using the three-flavor Polyakov loop extended Nambu--Jona-Lasinio (PNJL) model in which the anomalous magnetic moment (AMM) of the quarks is also taken into consideration. This is done by first evaluating the thermo-magnetic spectral function of the vector current correlator employing the real time formalism of finite temperature field theory and the Schwinger proper time formalism. The constituent quark mass which goes as an input in the expression of the dilepton production rate (DPR), has been calculated using the three-flavor PNJL model employing Pauli-Villiars (PV) regularization. The obtained constituent quark mass being strongly dependent on the temperature, density, magnetic field and AMM of the quarks, captures the effect of `strong' interactions specifically around the (pseudo) chiral and confinement-deconfinement phase transition regions. The analytic structure of the spectral function in the complex energy plane has been analyzed in detail and a non-trivial Landau cut is found in the physical kinematic domains resulting from the scattering of the Landau quantized quark/antiquark with the photon which is purely a finite magnetic field effect. Due to the emergence of the Landau cut along with the usual unitary cut, the DPR is found to be largely enhanced in the low invariant mass region. Owing to the magnetic field and AMM dependence of the thresholds of these cuts, we find that the kinematically forbidden gap between the Unitary and Landau cuts vanishes at sufficiently high temperature, density and magnetic field leading to the generation of a continuous spectrum of dilepton emission over the whole invariant mass region. In order to see the effects of strangeness and confinement-deconfinement, the rates are compared with the three-flavor NJL and the two-flavor NJL and PNJL models.
Comments:
Version published in Physical Review D
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2104.11425 [pdf]
PRD(2021)·35 citations
05
[Submitted on 23 Apr 2021] (cross-list from hep-ph)
Skyrmions in a magnetic field and $π^{0}$ domain wall formation in dense nuclear matter
Shi Chen🇯🇵 · Kenji Fukushima🇯🇵 · Zebin Qiu🇯🇵
We elucidate magnetic effects in the skyrmion system to probe into the dense nuclear matter. We find a deformed $π^{0}$ dipole structure of a baryon induced by a magnetic field. We then extend our scope to stacked Skyrme crystal layers to scrutinize phases of magnetized nuclear matter. We observe a quantized magnetic flux and identify a phase transition from a crystalline state to a $π^{0}$ domain wall corresponding to a topological transmutation from $π_{3} (S^{3})$ to $π_{1} (S^{1})$ . We establish the phase diagram, which could be explored also in analogous systems with two-component Bose-Einstein condensates.
Comments:
6 pages, 5 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2104.11482 [pdf]
PRD(2022)·32 citations
06
[Submitted on 23 Apr 2021] (cross-list from hep-ph)
Novel observables for exploring QCD collective evolution and quantum entanglement within individual jets
Austin Baty🇺🇸 · Parker Gardner🇺🇸 · Wei Li🇺🇸
We postulate that non-perturbative QCD effects occurring during parton fragmentation can result in collective effects of a multi-parton system, reminiscent of those observed in high-energy hadronic or nuclear interactions with large final-state particle multiplicity. Proton-proton collisions at the Large Hadron Collider showed surprising signatures of a strongly interacting, thermalized quark-gluon plasma, which was thought only to form in collisions of large nuclear systems. Another puzzle observed earlier in $e^{+} e^{-}$ collisions is that production yields of various hadron species appear to follow a thermal-like distribution with a common temperature. We propose searches for thermal and collective properties resulting from parton fragmentation processes using high multiplicity jets in high-energy elementary collisions. Several novel observables are studied using the PYTHIA 8 Monte Carlo event generator. Experimental observation of such collectivity will offer a new view of non-perturbative QCD dynamics of multi-parton systems at the smallest scales. Absence of any collective effects may offer new insights into the role of quantum entanglement in the observed thermal behavior of particle production in high energy collisions.
Comments:
14 pages, 12 figures. Updated to mirror version accepted by journal
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2104.11735 [pdf]
PRC(2023)·37 citations
07
[Submitted on 23 Apr 2021] (cross-list from astro-ph.SR)
"In-System" Fission-Events: An Insight into Puzzles of Exoplanets and Stars?
Elizabeth P. Tito🇺🇸 · Vadim I. Pavlov🇫🇷
In expansion of our recent proposal (Physics, 2020, 2, 213-276) that the solar system's evolution occurred in two stages -- during the first stage, the gaseous giants formed (via disk instability), and, during the second stage (caused by an encounter with a particular stellar-object leading to "in-system" fission-driven nucleogenesis), the terrestrial planets formed (via accretion) -- we emphasize here that the mechanism of formation of such stellar-objects is generally universal and therefore encounters of such objects with stellar-systems may have occurred elsewhere across galaxies. If so, their aftereffects may perhaps be observed as puzzling features in the spectra of individual stars (such as idiosyncratic chemical enrichments) and/or in the structures of exoplanetary systems (such as unusually high planet densities or short orbital periods). This paper reviews and reinterprets astronomical data within the "fission-events framework." Classification of stellar systems as "pristine" or "impacted" is offered.
Comments:
Review, 26 pages, 13 figures
Subjects:
Solar and Stellar Astrophysics (astro-ph.SR); astro-ph.EP (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2104.11744 [pdf]
Universe(2021)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Correspondence between momentum dependent relaxation time and field redefinition of relativistic hydrodynamic theory

Low-energy dipole excitations in 20O with antisymmetrized molecular dynamics

Intermittency analysis of proton numbers in heavy-ion collisions at energies available at the BNL Relativistic Heavy Ion Collider

Dilepton production from magnetized quark matter with an anomalous magnetic moment of the quarks using a three-flavor PNJL model

Skyrmions in a magnetic field and π0 domain wall formation in dense nuclear matter

Novel observables for exploring QCD collective evolution and quantum entanglement within individual jets

"In-System" Fission-Events: An Insight into Puzzles of Exoplanets and Stars?

Affiliations

Low-energy dipole excitations in $^{20}$ O with antisymmetrized molecular dynamics

Skyrmions in a magnetic field and $π^{0}$ domain wall formation in dense nuclear matter