Nuclear Theory·nucl-th

Tuesday·June 9, 2020

17 papers—7 primary·10 cross-listed

08
[Submitted on 5 Jun 2020] (cross-list from astro-ph.HE)
Studying the parameters of the extended $σ$ - $ω$ model for neutron star matter
David Alvarez-Castillo🇵🇱 · Alexander Ayriyan🇷🇺 · Gergely Gábor Barnaföldi🇭🇺 · Hovik Grigorian🇷🇺 · Péter Pósfay🇭🇺
In this work we study the parameters of the extended $σ$ - $ω$ model for neutron star matter by a Bayesian analysis on state-of-the-art multi-messenger astronomy observations, namely mass, radius and tidal deformabilities. We have considered three parameters of the model, the Landau mass $m_{L}$ , the nuclear compressibility $K_{0}$ , and the value of the symmetry energy $S_{0}$ , all at saturation density $n_{0}$ . As a result, we are able to estimate the values of the Landau mass of f $m_{L} = 739 \pm 17$ MeV, whereas the values of $K_{0}$ and $S_{0}$ fall within already known empirical values. Furthermore, for neutron stars we find the most probable value of 13 km $< R_{1.4} <$ 13.5 km and the upper mass limit of $M_{ma x} \approx 2.2$ M $_{⊙}$ .
Comments:
14 pages, 15 figures, 2 tables. Typos corrected
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2006.03676 [pdf]
Eur.Phys.J.ST(2020)·13 citations
09
[Submitted on 5 Jun 2020] (cross-list from astro-ph.HE)
Estimating Compressibility from Maximal-mass Compact Star Observations
Gergely Gábor Barnaföldi · Péter Pósfay · Balázs E. Szigeti · Antal Jakovác
We investigated recent observation data of pulsar masses of PSR J0740 $+$ 6620, PSR J0348 $+$ 0432, and PSR J1614 $-$ 2230 based on the extended $σ$ - $ω$ model. We assumed that these pulsars are maximal mass compact star, which suggest that the core approximation can be applied. Using the linear relations between the microscopic and macroscopic parameters of neutron stars suggested by this model, we estimated the values of the nucleon Landau mass and nuclear compressibility $m_{L} = 776. 0_{- 84.9}^{+ 38.5}$ ~MeV and $K = 242. 7_{- 28.0}^{+ 57.2}$ , respectively.
Comments:
10 pages and 2 figures
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2006.03710 [pdf]
Eur.Phys.J.ST(2020)·4 citations
10
[Submitted on 6 Jun 2020] (cross-list from hep-ph)
Lambda(1405) as a K-bar N Feshbach resonance in the Skyrme model
Takashi Ezoe🇯🇵 · Atsushi Hosaka🇯🇵
We describe the Lambda(1405) hyperon as a Feshbach resonance of a bar-KN quasi-bound state coupled by a decaying channel of pi Sigma in the Skyrme model. A weakly bound bar-KN state is generated in the laboratory frame, while the Sigma hyperon as a strongly bound state of bar-KN in the intrinsic frame. We obtain a coupling of bar-KN and pi Sigma channels by computing a baryon matrix element of the axial current. This coupling enables the decay of the bar-KN bound state to pi-Sigma . It is shown that the Skyrme model supports the Lambda(1405) as a narrow Feshbach resonance.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2006.03788 [pdf]
PRD(2020)·9 citations
11
[Submitted on 6 Jun 2020] (cross-list from astro-ph.HE)
Constraining the onset density of the hadron-quark phase transition with gravitational-wave observations
Sebastian Blacker🇩🇪 · Niels-Uwe F. Bastian🇵🇱 · Andreas Bauswein🇩🇪 · David B. Blaschke🇵🇱 · Tobias Fischer🇵🇱 · Micaela Oertel🇫🇷 · Theodoros Soultanis🇩🇪 · Stefan Typel🇩🇪
We study the possible occurrence of the hadron-quark phase transition (PT) during the merging of neutron star binaries by hydrodynamical simulations employing a set of temperature dependent hybrid equations of state (EoSs). Following previous work we describe an unambiguous and measurable signature of deconfined quark matter in the gravitational-wave (GW) signal of neutron star binary mergers including equal-mass and unequal-mass systems of different total binary mass. The softening of the EoS by the PT at higher densities, i.e. after merging, leads to a characteristic increase of the dominant postmerger GW frequency f_peak relative to the tidal deformability Lambda inferred during the premerger inspiral phase. Hence, measuring such an increase of the postmerger frequency provides evidence for the presence of a strong PT. If the postmerger frequency and the tidal deformability are compatible with results from purely baryonic EoS models yielding very tight relations between f_peak and Lambda, a strong PT can be excluded up to a certain density. We find tight correlations of f_peak and Lambda with the maximum density during the early postmerger remnant evolution. These GW observables thus inform about the density regime which is probed by the remnant and its GW emission. Exploiting such relations we devise a directly applicable, concrete procedure to constrain the onset density of the QCD PT from future GW measurements. We point out two interesting scenarios: if no indications for a PT are inferred from a GW detection, our procedure yields a lower limit on the onset density of the hadron quark PT. On the contrary, if a merger event reveals evidence for the occurrence of deconfined quark matter, the inferred GW parameters set an upper limit on the PT onset density. (abridged)
Comments:
35 pages, 24 figures; accepted for publication in Phys. Rev. D
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2006.03789 [pdf]
PRD(2020)·119 citations
12
[Submitted on 6 Jun 2020] (cross-list from physics.atom-ph)
Search for CP-violating nuclear magnetic quadrupole moment using the LuOH $^{+}$ cation
D.E. Maison🇷🇺 · L.V. Skripnikov🇷🇺 · V.V. Flambaum🇦🇺 · M. Grau🇨🇭
The CP-violating interaction of the nuclear magnetic quadrupole moment (MQM) of the $^{175}$ Lu nucleus with electrons in the molecular cation LuOH $^{+}$ is studied. The resulting effect is expressed in terms of CP-odd parameters, such as quantum chromodynamics angle $θ ˉ$ , quark electric dipole moment (EDM) and chromo-EDM. For this we have performed a calculation of the nuclear MQM as well as the molecular constant that characterises the interaction of this MQM of $^{175}$ Lu with electrons. Additionally, we predict the hyperfine structure constants for the ground electronic state of LuOH $^{+}$ . We conclude that LuOH $^{+}$ is a promising system to measure the nuclear MQM.
Subjects:
Atomic Physics (physics.atom-ph); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2006.03848 [pdf]
J.Chem.Phys.(2020)·23 citations
13
[Submitted on 6 Jun 2020] (cross-list from hep-ph)
Study of the ground state energies of some nuclei using hybrid model
R. Hussien🇪🇬 · Sh. M. Sewailem🇪🇬 · L. I. Abou-Salem🇪🇬
The quark-quark QQ interaction as a perturbed term to the nucleon-nucleon interaction NN without any coupling between them is studied in a hybrid model. This model is used to calculate the ground-state energies of 2H1 and 4He2 nuclei. In a semi-relativistic framework, this model is encouraged for light nuclei and the instanton induced interaction by using the QQ potential and the NN interaction for a small scale around the hadron boundaries. This hybrid model depends on two theories, the one-boson exchange potential OBEP and the Cornell-dressed potential CDP for QQ. A small effect of quark-quark interaction is obtained on the values of the ground state energies, around 6.7 for 2H1 and 1.2 for 4He2 by using the considered hybrid model.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2006.03956 [pdf]
Adv.High Energy Phys.(2021)·0 citations
14
[Submitted on 7 Jun 2020] (cross-list from nucl-ex)
Quantification of the Chiral Magnetic Effect in Au+Au collisions at $s_{NN} = 200$ GeV
Roy A. Lacey (1) · Niseem Magdy (2) ((1) Depts. of Chemistry and Physics, Stony Brook University, Stony Brook USA, (2) Department of Physics, University of Illinois at Chicago, Chicago, Illinois, USA)
The Multi-Phase Transport model, AMPT, and the Anomalous Viscous Fluid Dynamics model, AVFD, are used to assess a possible chiral-magnetically-driven charge separation ( $Δ S$ ) recently measured with the $R_{Ψ_{2}} (Δ S)$ correlator in Au+Au collisions at $s_{NN} = 200$ GeV. The Comparison of the experimental and simulated $R_{Ψ_{2}} (Δ S)$ distributions indicates that background-driven charge separation is insufficient to account for the measurements. The AVFD model calculations, which explicitly account for CME-driven anomalous transport in the presence of background, indicate a CME signal quantified by the $P$ -odd Fourier dipole coefficient $a_{1}^{'} \approx 0.5%$ in mid-central collisions. A similar evaluation for the $Δ γ$ correlator suggests that only a small fraction of this signal ( $f_{CME} = Δ γ_{CME} /Δ γ \approx 25%$ ) is measurable with this correlator in the same collisions. The related prediction for signal detection in isobaric collisions of Ru+Ru and Zr+Zr are also presented.
Comments:
5 pages, 3 figures, submitted for publication. arXiv admin note: text overlap with arXiv:2002.07934
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2006.04132 [pdf]
2 citations
15
[Submitted on 7 Jun 2020] (cross-list from hep-ph)
Thermodynamic and Transport Properties of Matter Formed in $pp$ , $p$ -Pb, Xe-Xe and Pb-Pb Collisions at the Large Hadron Collider using Color String Percolation Model
Dushmanta Sahu🇮🇳 · Raghunath Sahoo🇮🇳
To have a better understanding of the matter formed in ultra-relativistic collisions, using the Color String Percolation Model (CSPM), we have estimated initial energy density, mean free path, squared speed of sound, shear viscosity to entropy density ratio ( $η / s$ ), bulk viscosity to entropy density ratio and bulk modulus for $pp$ , $p$ -Pb, Xe-Xe and Pb-Pb collisions at the Large Hadron Collider (LHC). These observables are studied as a function of final state charged particle multiplicity density and initial state percolation temperature. The results from this work are compared with the results from well known QCD models and with the transport properties of matter found in day-to-day life. These observables allow us to conclude an array of important findings about the matter formed in high energy collisions at the LHC. This work gives a threshold of charged particle multiplicity $⟨ d N_{c h} / d η ⟩ ≃$ 20, after which there are indications of change in the dynamics of the systems. The critical initial energy density and temperature as estimated by lattice QCD, are observed to be achieved for events with final state multiplicity $⟨ d N_{c h} / d η ⟩ \geq$ 20. In addition, for these high-multiplicity events, the estimated $η / s$ are comparable with that is observed for heavy-ion collisions, which is an indication of a strongly coupled Quark Gluon Plasma. This makes LHC high-multiplicity $pp$ collision events as probable candidates for the search of QGP droplets.
Comments:
Same as the published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2006.04185 [pdf]
J.Phys.G(2021)·23 citations
16
[Submitted on 7 Jun 2020] (cross-list from nucl-ex)
Charge separation measurements in $p$ ( $d$ )+Au and Au+Au collisions; implications for the chiral magnetic effect
STAR Collaboration
Charge separation ( $Δ S$ ) measurements, obtained relative to the $2^{nd}$ -order ( $Ψ_{2}$ ) and $3^{rd}$ -order ( $Ψ_{3}$ ) event planes with a new charge-sensitive correlator $R_{Ψ_{m}} (Δ S)$ , are presented for $p$ ( $d$ )+Au and Au+Au collisions at $s_{N N} = 200$ ~GeV. The correlator, which is sensitive to the hypothesized Chiral Magnetic Effect (CME), show the expected patterns of background-driven charge separation for the measurements relative to $Ψ_{3}$ and those relative to $Ψ_{2}$ for the $p$ ( $d$ )+Au systems. By contrast, the Au+Au measurements relative to $Ψ_{2}$ , show event-shape-independent $R_{Ψ_{2}} (Δ S)$ distributions consistent with a CME-driven charge separation, quantified by widths having an inverse relationship to the Fourier dipole coefficient $a ~_{1}$ , which evaluates the CME. The extracted values of these widths and their dependencies on centrality and event-shape give new constraints for possible CME-driven charge separation in relativistic heavy-ion collisions.
Comments:
It is identified that results of the R_Psi3(Delta-S) correlator are invalid because of a programming error; no such error has been identified in the R_Psi2(Delta-S). AMPT results in Fig. 1(a) are improperly constructed and thus cannot be used to compare with the data. The manuscript is withdrawn from journal consideration; accordingly, the authors withdraw all conclusions of the manuscript
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2006.04251 [pdf]
14 citations
17
[Submitted on 7 Jun 2020] (cross-list from astro-ph.HE)
The remnant of GW170817: a trapped neutron star with a hypermassive incompressible superfluid core
A.A. Hujeirat · R. Samtaney
Our bimetric spacetime model of glitching pulsars is applied to the remnant of GW170817. Accordingly, pulsars are born with embryonic incompressible superconducting gluon-quark superfluid cores (SuSu-matter) that are embedded in Minkowski spacetime, whereas the ambient compressible and dissipative media (CDM) are imbedded in curved spacetime. As pulsars cool down, the equilibrium between both spacetime is altered, thereby triggering the well-observed glitch phenomena. Based thereon and assuming all neutron stars (NSs) to be born with the same initial mass of $M_{N S} (t = 0) \approx 1.25 M_{⊙},$ we argue that the remnant of GW170817 should be a relatively faint NS with a hypermassive central core made of SuSu-matter. The effective mass and radius of the remnant are predicted to be $[2.8 M_{⊙} < M_{r e m} \leq 3.351 M_{⊙}]$ and $R_{r e m} = 10.764$ km, whereas the mass of the enclosed SuSu-core is $M_{cor e} = 1.7 M_{⊙} .$ Here, about $1/2 M_{cor e}$ is an energy enhancement triggered by the phase transition of the gluon-quark-plasma from the microscopic into macroscopic scale. The current compactness of the remnant is $α_{c} = 0.918,$ but predicted to increase as the CDM and cools down, rendering the remnant an invisible dark energy object, and therefore to an excellent black hole candidate.
Comments:
13 pages, 8 figures
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
2006.04257 [pdf]
2 citations

Affiliations

first authorsco-authorsvia INSPIRE