Nuclear Theory·nucl-th

Tuesday·July 20, 2021

18 papers—8 primary·10 cross-listed

09
[Submitted on 16 Jul 2021] (cross-list from astro-ph.HE)
On the moment of inertia of PSR J0737-3039 A from LIGO/Virgo and NICER
Zhiqiang Miao · Ang Li · Zi-Gao Dai
We perform a Bayesian analysis of neutrons star moment of inertia by utilizing the available gravitational-wave data from LIGO/Virgo (GW170817 and GW190425) and mass-radius measurements from the Neutron Star Interior Composition Explorer (PSR J0030+0415 and PSR J0740+6620), incorporating the possible phase transition in the pulsar inner core. We find that the moment of inertia of pulsar A in the double pulsar binary J0737-3039 is $\sim 1.30 \times 1 0^{45} g c m^{2}$ , which only slightly depends on the employed hadronic equation of states. We also demonstrate how a moment of inertia measurement would improve our knowledge of the equation of state and the mass-radius relation for neutron stars and discuss whether a quark deconfinement phase transition is supported by the available data and forthcoming data that could be consistent with this hypothesis. We find that if pulsar A is a quark star, that its moment of inertia is a large value of $\sim 1.55 \times 1 0^{45} g c m^{2}$ suggesting the possibility of distinguishing it from (hybrid-)neutron stars with measurements of PSR J0737-3039A moment of inertia. We finally demonstrate the moment-of-inertia-compactness universal relations and provide analytical fits for both (hybrid-)neutron star and quark star results based on our analysis.
Comments:
10 pages, 8 figures, 4 tables, MNRAS (2022) accepted
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
arXiv:
2107.07979 [pdf]
MNRAS(2022)·38 citations
10
[Submitted on 16 Jul 2021] (cross-list from cond-mat.quant-gas)
Ultracold spin-balanced fermionic quantum liquids with renormalized $P$ -wave interactions
J. M. Alarcón🇪🇸 · J. A. Oller🇪🇸
We consider a spin-balanced degenerate gas of spin-1/2 fermions whose dynamics is governed by low-energy $P$ -wave interactions, characterized by the scattering volume $a_{1}$ and effective momentum $r_{1}$ . The energy per particle $E ˉ$ in the many-body system is calculated by resumming the ladder diagrams comprising both particle-particle and hole-hole intermediate states, following the novel advances recently developed by us in Ann.Phys. 437,168741(2022). This allows to obtain a renormalized result for $E ˉ$ within generic cutoff regularization schemes, with $E ˉ$ directly expressed in terms of the scattering parameters $a_{1}$ and $r_{1}$ , once the cut off is sent to infinity. The whole set of possible values of $a_{1}$ and $r_{1}$ is explored for the first time in the literature looking for minima in the energy per particle with $E ˉ$ given as described. They are actually found, but a further inspection reveals that the associated scattering parameters give rise to resonance poles in the complex momentum-plane with positive imaginary part, which is at odds with the Hermiticity of the Hamiltonian. We also determine that these conflictive poles, with a pole-position momentum that is smaller in absolute value than the Fermi momentum of the system, clearly impact the calculation of $E ˉ$ . As a result, we conclude that unpolarized spin-1/2 fermionic normal matter interacting in $P$ -wave is not stable. We also study three universal parameters around the unitary limit. Finally, the whole set of values for the parameters $a_{1}$ , $r_{1}$ is characterized according to whether they give rise to unallowed poles and, if so, by attending to their pole positions relative to the Fermi momentum of the system explored.
Comments:
Version that matches the published one. 15 pages, 8 figures, 2 tables
Subjects:
Quantum Gases (cond-mat.quant-gas); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2107.08051 [pdf]
PRC(2022)·5 citations
11
[Submitted on 16 Jul 2021] (cross-list from astro-ph.HE)
X-ray bounds on cooling, composition, and magnetic field of the Cassiopeia A neutron star and young central compact objects
Wynn C. G. Ho (Haverford)🇺🇸 · Yue Zhao (Alberta)🇨🇦 · Craig O. Heinke (Alberta)🇨🇦 · D. L. Kaplan (Wisconsin-Milwaukee)🇺🇸 · Peter S. Shternin (Ioffe Institute)🇷🇺 · M. J. P. Wijngaarden (Southampton)🇬🇧
We present analysis of multiple Chandra and XMM-Newton spectra, separated by 9-19 years, of four of the youngest central compact objects (CCOs) with ages < 2500 yr: CXOU J232327.9+584842 (Cassiopeia A), CXOU J160103.1-513353 (G330.2+1.0), 1WGA J1713.4-3949 (G347.3-0.5), and XMMU J172054.5-372652 (G350.1-0.3). By fitting these spectra with thermal models, we attempt to constrain each CCO's long-term cooling rate, composition, and magnetic field. For the CCO in Cassiopeia A, 14 measurements over 19 years indicate a decreasing temperature at a ten-year rate of 2.2+/-0.2 or 2.8+/-0.3 percent (1sigma error) for a constant or changing X-ray absorption, respectively. We obtain cooling rate upper limits of 17 percent for CXOU J160103.1-513353 and 6 percent for XMMU J172054.5-372652. For the oldest CCO, 1WGA J1713.4-3949, its temperature seems to have increased by 4+/-2 percent over a ten year period. Assuming each CCO's preferred distance and an emission area that is a large fraction of the total stellar surface, a non-magnetic carbon atmosphere spectrum is a good fit to spectra of all four CCOs. If distances are larger and emission areas are somewhat smaller, then equally good spectral fits are obtained using a hydrogen atmosphere with B <= 7x10^10 G or B >= 10^12 G for CXOU J160103.1-513353, B <= 10^10 G or B >= 10^12 G for XMMU J172054.5-372652, and non-magnetic hydrogen atmosphere for 1WGA J1713.4-3949. In a unified picture of CCO evolution, our results suggest most CCOs, and hence a sizable fraction of young neutron stars, have a surface magnetic field that is low early in their life but builds up over several thousand years.
Comments:
15 pages, 9 figures; accepted for publication in MNRAS
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2107.08060 [pdf]
MNRAS(2021)·30 citations
12
[Submitted on 17 Jul 2021] (cross-list from hep-ph)
Collective modes in anisotropic plasmas
Margaret E. Carrington🇨🇦 · Bailey M. Forster🇨🇦 · Sofiya Makar🇨🇦
We study collective modes in anisotropic plasmas of quarks and gluons using a quasi-particle picture and a hard loop approximation. We use a general class of anisotropic distribution functions, and we consider chirally asymmetric systems. We introduce a complete tensor basis to decompose the gluon polarization tensor into a set of nine scalar functions. We derive and solve the corresponding dispersion equations. Imaginary modes are particularly important because of their potential influence on plasma dynamics. We explore in detail their dependence on the chiral chemical potential and the parameters that characterise the anisotropy of the system. We show that our generalized distributions produce dispersion relations that are much richer in structure than those obtained with a simple one parameter deformation of an isotropic distribution. In addition, the size and domain of the imaginary solutions are enhanced, relative to those obtained with a one parameter deformation. Finally, we show that the influence of even a very small chiral chemical potential is significantly magnified when anisotropy is present.
Comments:
31 pages, 13 figures, published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2107.08229 [pdf]
PRC(2021)·14 citations
13
[Submitted on 17 Jul 2021] (cross-list from physics.acc-ph)
ERLC (Twin LC) and LHC/FCC Based eA Colliders
A. N. Akay🇹🇷 · B. Dagli🇹🇷 · B. Ketenoglu🇹🇷 · S. Sultansoy🇹🇷
Construction of the ERLC (twin LC) collider tangential to LHC or FCC will give opportunity to realize eA collisions at multi-TeV center-of-mass energies. Luminosity estimations show that values comparable with that of ERL60 based eA colliders are achievable while center of mass energies are essentially higher. Certainly, proposed eA colliders have great potential for clarifying QCD basics and nuclear structure.
Comments:
arXiv admin note: substantial text overlap with arXiv:2107.04850
Subjects:
Accelerator Physics (physics.acc-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2107.08312 [pdf]
1 citation
14
[Submitted on 19 Jul 2021] (cross-list from hep-ph)
Hidden charm pentaquark states in a diquark model
Pan-Pan Shi🇨🇳 · Fei Huang🇨🇳 · Wen-Ling Wang🇨🇳
The mass spectrum of hidden charm pentaquark states composed of two diquarks and an antiquark are calculated by use of an effective Hamiltonian which includes explicitly the spin, color, and flavor dependent interactions. The results show that the $P_{c} (4312)^{+}$ and $P_{c} (4440)^{+}$ states could be explained as hidden charm pentaquark states with isospin and spin-parity $I J^{P} = 1/2 (3/ 2^{-})$ , the $P_{c} (4457)^{+}$ state could be explained as a hidden charm pentaquark state with $I J^{P} = 1/2 (5/ 2^{-})$ , and the $P_{cs} (4459)^{+}$ state could be explained as a hidden charm pentaquark state with $I J^{P} = 0 (1/ 2^{-})$ or $0 (3/ 2^{-})$ . Predications for the masses of other possible pentaquark states are also given, and the possible decay channels of these hidden charm pentaquark states are discussed.
Comments:
9 pages
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2107.08680 [pdf]
EPJA(2021)·37 citations
15
[Submitted on 19 Jul 2021] (cross-list from hep-ph)
Hydrodynamical attractor and thermal particle production in heavy-ion collision
Lakshmi J. Naik🇮🇳 · Sunil Jaiswal🇮🇳 · K. Sreelakshmi🇮🇳 · Amaresh Jaiswal🇮🇳 · V. Sreekanth🇮🇳
Study of thermal particle production is crucial to understand the space-time evolution of the fireball produced in high energy heavy-ion collisions. We consider thermal particle production within the framework of relativistic viscous hydrodynamics and employ recently obtained analytical solutions of higher-order viscous hydrodynamics with longitudinal Bjorken expansion to calculate the spectra of dileptons and photons. Using these analytical solutions, we constrain the allowed initial states by demanding positivity and reality of energy density throughout the evolution. Further, we compute thermal particle spectra and study the particle yield in context of hydrodynamic attractors. We find that, of all allowed solutions, the evolution corresponding to attractor solution leads to maximum production of thermal particles.
Comments:
13 pages, 10 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2107.08791 [pdf]
11 citations
16
[Submitted on 19 Jul 2021] (cross-list from hep-ph)
The role of proton-antiproton regeneration in the late stages of heavy-ion collisions
Oscar Garcia-Montero🇩🇪 · Jan Staudenmaier🇩🇪 · Anna Schäfer🇩🇪 · Juan M. Torres-Rincon🇩🇪 · Hannah Elfner🇩🇪
We investigate the long-standing question of the effect of proton-antiproton annihilation on the (anti-)proton yield, while respecting detailed balance for the 5-body back-reaction for the first time in a full microscopic description of the late stages of heavy-ion collisions. This is achieved by employing a stochastic collision criterion in a hadronic transport approach (SMASH), which allows to treat arbitrary multi-particle reactions. It is used to account for the regeneration of (anti-)protons via $5 π \to p p ˉ$ . Our results show that a back-reaction happens for a fraction of 15-20\% of all annihilations. Within a viscous hybrid approach Au+Au/Pb+Pb collisions from $s_{N N} = 17.3$ GeV $- 5.02$ TeV are investigated and the quoted fraction is independent of the beam energy or centrality of the collision. Taking the back-reaction into account results in regeneration of half of the (anti-)proton yield that is lost due to annihilations at midrapidity. We also find that, concerning the multiplicities, treating the back-reaction as a chain of 2-body reactions is equivalent to a single 5-to-2 reaction.
Comments:
6 pages, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2107.08812 [pdf]
PRC(2022)·28 citations
17
[Submitted on 19 Jul 2021] (cross-list from hep-lat)
Unpolarized gluon distribution in the nucleon from lattice quantum chromodynamics
Tanjib Khan🇺🇸 · Raza Sabbir Sufian🇺🇸 · Joseph Karpie🇺🇸 · Christopher J. Monahan🇺🇸 · Colin Egerer🇺🇸 · Bálint Joó🇺🇸 · Wayne Morris🇺🇸 · Kostas Orginos🇺🇸 · Anatoly Radyushkin🇺🇸 · David G. Richards🇺🇸 · Eloy Romero🇺🇸 · Savvas Zafeiropoulos🇫🇷
In this study, we present a determination of the unpolarized gluon Ioffe-time distribution in the nucleon from a first principles lattice quantum chromodynamics calculation. We carry out the lattice calculation on a $3 2^{3} \times 64$ ensemble with a pion mass of $358$ MeV and lattice spacing of $0.094$ fm. We construct the nucleon interpolating fields using the distillation technique, flow the gauge fields using the gradient flow, and solve the summed generalized eigenvalue problem to determine the glounic matrix elements. Combining these techniques allows us to provide a statistically well-controlled Ioffe-time distribution and unpolarized gluon PDF. We obtain the flow time independent reduced Ioffe-time pseudo-distribution, and calculate the light-cone Ioffe-time distribution and unpolarized gluon distribution function in the $MS$ scheme at $μ = 2$ GeV, neglecting the mixing of the gluon operator with the quark singlet sector. Finally, we compare our results to phenomenological determinations.
Comments:
23 pages, 12 figures, Phys Rev D accepted version
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2107.08960 [pdf]
PRD(2021)·80 citations
18
[Submitted on 19 Jul 2021] (cross-list from nucl-ex)
Heavy Flavor and Jet Studies for the Future Electron-Ion Collider to Explore the Hadronization Process
Xuan Li🇺🇸
Heavy flavor production at the future Electron-Ion Collider (EIC) will allow us to precisely determine the quark/gluon fragmentation processes in vacuum and the nuclear medium especially within the poorly constrained kinematic region. Heavy flavor hadron and jet reconstruction with the recent EIC detector design have been studies in simulation. Results of corresponding physics projections such as the flavor dependent hadron nuclear modification factor $R_{e A}$ in electron+nucleus collisions will be shown. The statistical precision obtained by these proposed heavy flavor measurements for the future EIC provides a strong discriminating power in separating different theoretical predictions.
Comments:
6 pages, 5 figures. Submission to SciPost. DIS2021 proceeding. This work is supported by the LANL LDRD 20200022DR project
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2107.09035 [pdf]
SciPost Phys.Proc.(2022)·6 citations

Affiliations

first authorsco-authorsvia INSPIRE