Nuclear Theory·nucl-th

Wednesday·December 21, 2022

8 papers—3 primary·5 cross-listed

01
g-mode Oscillations in Neutron Stars with Hyperons
Vinh Tran🇺🇸 · Suprovo Ghosh🇮🇳 · Nicholas Lozano🇺🇸 · Debarati Chatterjee🇮🇳 · Prashanth Jaikumar🇺🇸
A common alternative to the standard assumption of nucleonic composition of matter in the interior of a neutron star is to include strange baryons, particularly hyperons. Any change in composition of the neutron star core has an effect on g-mode oscillations of neutron stars, through the compositional dependence of the equilibrium and adiabatic sound speeds. We study the core g-modes of a neutron star contaning hyperons, using a variety of relativistic mean field models of dense matter that satisfy observational constraints on global properties of neutron stars. Our selected models predict a sharp rise in the g-mode frequencies upon the onset of strange baryons. Should g-modes be observed in the near future, their frequency could be used to test the presence of hyperonic matter in the core of neutron stars.
nucl-thastro-ph.HEPRC(2023)·35 citations
02
Conformality and percolation threshold in neutron stars
Michał Marczenko🇵🇱 · Larry McLerran🇺🇸 · Krzysztof Redlich🇵🇱 · Chihiro Sasaki🇵🇱
Speed of sound is given attention in multi-messenger astronomy as it encodes information of the dense matter equation of state. Recently the trace anomaly was proposed as a more informative quantity. In this work, we statistically determine the speed of sound and trace anomaly and show that they are driven to their conformal values at the centers of maximally massive neutron stars. We show that the local peak in the speed of sound can be associated with deconfinement along with percolation conditions in QCD matter.
nucl-thastro-ph.HEEPJ Web Conf.(2022)·5 citations
03
New insights into the pole parameters of the $Λ (1380)$ , the $Λ (1405)$ and the $Σ (1385)$
Daniel Sadasivan🇨🇱 · Maxim Mai🇩🇪 · Michael Döring🇺🇸 · Ulf-G. Meißner🇩🇪 · Felipe Amorim🇨🇱 · John Paul Klucik🇨🇱 · Jun-Xu Lu🇨🇳 · Li-Sheng Geng🇨🇳
A coupled-channel S- and P-wave next-to-leading order chiral-unitary approach for strangeness $S = - 1$ meson-baryon scattering is extended to include the new data from the KLOE and AMADEUS experiments as well as the $Λ π$ mass distribution of the $Σ (1385)$ . The positions of the poles on the second Riemann sheet corresponding to the $Σ (1385)$ pole and the $Λ (1380)$ and $Λ (1405)$ poles as well as the couplings of these states to various channels are calculated. We find that the resonance positions and branching ratios are on average determined with about 20\% higher precision when including the KLOE and AMADEUS data. Additionally, for the first time, the correlations between the parameters of the poles are investigated and shown to be relevant. We also find that the $Σ (1385)$ has negligible influence on the properties of the $Λ$ states given the available data. Still, we identify isospin-1 cusp structures in the present solution in light of new measurements of $π^{\pm} Λ$ line-shapes by the Belle collaboration.
nucl-thhep-phnucl-exFront.Phys.(2023)·17 citations
04
A systematic formulation of chiral anomalous magnetohydrodynamics
Michael J. Landry🇺🇸 · Hong Liu🇺🇸
We present a new way of deriving effective theories of dynamical electromagnetic fields in general media. It can be used to give a systematic formulation of magnetohydrodynamics (MHD) with strong magnetic fields, including systems with chiral matter and Adler-Bell-Jackiw (ABJ) anomaly. We work in the regime in which velocity and temperature fluctuations can be neglected. The resulting chiral anomalous MHD incorporates and generalizes the chiral magnetic effect, the chiral separation effect, the chiral electric separation effect, as well as recently derived strong-field MHD, all in a single coherent framework. At linearized level, the theory predicts that the chiral magnetic wave does not survive dynamical electromagnetic fields. A different chiral wave, to which we refer as the chiral magnetic electric separation wave, emerges as a result of dynamical versions of the chiral electric separation effect and the chiral magnetic effect. We predict its wave velocity. We also introduce a simple, but solvable nonlinear model to explore the fate of the chiral instability.
↳ hep-phastro-ph.HEcond-mat.mes-hallhep-th+1JHEP(2026)·18 citations
05
Towards an effective action for chiral magnetohydrodynamics
Arpit Das🇬🇧 · Nabil Iqbal🇬🇧 · Napat Poovuttikul🇬🇧
We consider chiral magnetohydrodynamics, i.e. a finite-temperature system where an axial $U (1)$ current is not conserved due to an Adler-Bell-Jackiw anomaly saturated by the dynamical operator $F_{μν} F ~^{μν}$ . We express this anomaly in terms of the 1-form symmetry associated with magnetic flux conservation and study its realization at finite temperature. We present Euclidean generating functional and dissipative action approaches to the dynamics and reproduce some aspects of chiral MHD phenomenology from an effective theory viewpoint, including the chiral separation and magnetic effects. We also discuss the construction of non-invertible axial symmetry defect operators in our formalism.
↳ hep-thastro-ph.HEhep-phnucl-th+122 citations
06
Topological Dimensions from Disorder and Quantum Mechanics?
Ivan Horváth · Peter Markoš
We have recently shown that critical Anderson electron in $D = 3$ dimensions effectively occupies a spatial region of infrared (IR) scaling dimension $d_{IR} \approx 8/3$ . Here we inquire about the dimensional substructure involved. We partition space into regions of equal quantum occurrence probability, such that points comprising a region are of similar relevance, and calculate the IR scaling dimension $d$ of each. This allows us to infer the probability density $p (d)$ for dimension $d$ to be accessed by electron. We find that $p (d)$ has a strong peak at $d$ very close to 2. In fact, our data suggests that $p (d)$ is non-zero on the interval $[d_{min}, d_{max}] \approx [4/3, 8/3]$ and may develop a discrete part ( $δ$ -function) at $d = 2$ in infinite-volume limit. The latter invokes the possibility that combination of quantum mechanics and pure disorder can lead to emergence of topological dimensions. Although $d_{IR}$ is based on effective counting of which $p (d)$ has no a priori knowledge, $d_{IR} \geq d_{max}$ is an exact feature of the ensuing formalism. Possible connection of our results to recent findings of $d_{IR} \approx 2$ in Dirac near-zero modes of thermal quantum chromodynamics is emphasized.
↳ cond-mat.dis-nnhep-lathep-thnucl-th+1Entropy(2023)·2 citations
07
The isentropic equation of state of (2+1)-flavor QCD: An update based on high precision Taylor expansion and Padé-resummed expansion at finite chemical potentials
Jishnu Goswami🇯🇵
The HotQCD Collaboration performed Taylor expansion calculations in 2017 for the pressure, energy density, and entropy density at non-zero chemical potentials up to the $6^{t h}$ order. Since then, they have significantly improved the statistics for lattices with temporal extents of $N_{τ} = 8$ and $12$ , and have also included results for $N_{τ} = 16$ that were not previously available. They have also calculated the $8^{t h}$ -order expansion coefficients for $N_{τ} = 8$ . These calculations showed that the Taylor series expansion for the pressure is accurate up to $μ_{B} / T \leq 2.5$ . In this study, we use the high-statistics results on Taylor expansion coefficients, calculated with HISQ fermions and extrapolated to the continuum limit, to determine the QCD equation of state under conditions relevant for hot and dense matter produced in heavy ion collisions. We also calculate the energy density and pressure along lines of constant entropy per net baryon number.
↳ hep-lathep-phnucl-thPoS(2023)·6 citations
08
Finite temperature QCD phase transition with 3 flavors of Möbius domain wall fermions
Yu Zhang🇯🇵 · Yasumichi Aoki🇯🇵 · Shoji Hashimoto🇯🇵 · Issaku Kanamori🇯🇵 · Takashi Kaneko🇯🇵 · Yoshifumi Nakamura🇯🇵
We investigate the finite temperature QCD phase transition with three degenerate quark flavors using Möbius domain wall fermions. To explore the order of phase transition on the lower left corner of Columbia plot and if possible, to locate the critical endpoint we performed simulations at temperatures around 181 and 121 MeV with lattice spacing $a = 0.1361 (20)$ fm corresponding to temporal lattice extent $N_{τ} = 8, 12$ with varying quark mass for two different volumes with aspect ratios $N_{σ} / N_{τ}$ ranging from 2 to 3. By analyzing the volume and mass dependence of the chiral condensate, disconnected chiral susceptibility and Binder cumulant we find that there is a crossover at $m_{q}^{MS} (2 GeV) \sim 44 MeV$ for $T_{pc} \sim$ 181 MeV, At temperature 121 MeV, the binder cumulant suggests a crossover at $m_{q}^{MS} (2 GeV) \sim 3.7 MeV$ , although a study of volume dependence would be important to confirm this.
↳ hep-lathep-phhep-thnucl-thPoS(2023)·13 citations

Affiliations

first authorsco-authorsvia INSPIRE