Nuclear Theory·nucl-th

Wednesday·December 22, 2021

10 papers—4 primary·6 cross-listed

05
Convergence of hydrodynamics in rapidly spinning strongly coupled plasma
Casey Cartwright🇺🇸 · Markus Garbiso Amano🇺🇸 · Matthias Kaminski🇺🇸 · Jorge Noronha🇺🇸 · Enrico Speranza🇺🇸
We compute the radius of convergence of the linearized relativistic hydrodynamic expansion around a non-trivially rotating strongly coupled N=4 Super-Yang-Mills plasma. Our results show that the validity of hydrodynamics is sustained and can even get enhanced in a highly vortical quark-gluon plasma, such as the one produced in heavy-ion collisions. The hydrodynamic dispersion relations are computed using a rotating background that is an analytic solution of the ideal hydrodynamic equations of motion with non-vanishing angular momentum and large vorticity gradients, giving rise to a particular boost symmetry. Analytic equations for the transport coeffcients of the rotating plasma as a function of their values in a plasma at rest are given.
↳ hep-thhep-phnucl-thPRD(2023)·36 citations
06
Constraining neutron star properties with a new equation of state insensitive approach
Bhaskar Biswas · Sayak Datta
Instead of parameterizing the pressure-density relation of a neutron star (NS), one can parameterize its macroscopic properties such as mass ( $M$ ), radius ( $R$ ), and dimensionless tidal deformability ( $Λ$ ) to infer the equation of state (EoS) combining electromagnetic and gravitational wave (GW) observations. We present a new method to parameterize $R (M)$ and $Λ (M)$ relations, which approximate the candidate EoSs with accuracy better than 5\% for all masses and span a broad region of $M - R - Λ$ plane. Using this method we combine the $M - Λ$ measurement from GW170817 and GW190425, and simultaneous $M - R$ measurement of PSR J0030+0451 and PSR J0740+6620 to place joint constraints on NS properties. At 90 \% confidence, we infer $R_{1.4} = 12.0 5_{- 0.87}^{+ 0.98}$ km and $Λ_{1.4} = 37 2_{- 150}^{+ 220}$ for a $1.4 M_{⊙}$ NS, and $R_{2.08} = 12.6 5_{- 1.46}^{+ 1.36}$ km for a $2.08 M_{⊙}$ NS. Furthermore, we use the inferred values of the maximum mass of a nonrotating NS $M_{max} = 2.5 2_{- 0.29}^{+ 0.33} M_{⊙}$ to investigate the nature of the secondary objects in three potential neutron star-black hole merger (NSBH) system.
↳ astro-ph.HEgr-qcnucl-thPRD(2022)·25 citations
07
Towards a discovery of BSM physics from the Cabibbo angle anomaly
Chien-Yeah Seng🇩🇪
New developments in both the theories and experiments related to the extraction of the top-row Cabibbo-Kobayashi-Maskawa matrix elements $V_{u d}$ and $V_{u s}$ led to a series of new anomalies, for instance the apparent violation of the top-row unitarity relation. It is important to further reduce all the associated Standard Model theory uncertainties in order to better understand whether such observations point towards the possibility of physics beyond the Standard Model, or rather some unexpectedly large Standard Model effects. This requires improved studies of tree-level and higher-order Standard Model corrections that enter the beta decays of pions, neutron, nuclei and kaons. We will briefly review the recent progress along this direction and discuss possible improvements in the future.
↳ hep-phhep-exhep-latnucl-ex+1Mod.Phys.Lett.A(2022)·7 citations
08
Searching for the BCS phase at nonzero isospin asymmetry
Bastian B. Brandt🇩🇪 · Francesca Cuteri🇩🇪 · Gergely Endrődi🇩🇪
According to perturbation theory predictions, QCD matter in the zero-temperature, high-density limits of QCD at nonzero isospin chemical potential is expected to be in a superfluid Bardeen-Cooper-Schrieffer (BCS) phase of $u$ and $d ˉ$ Cooper pairs. It is also expected, on symmetry grounds, that such phase connects via an analytical crossover to the phase with Bose-Einstein condensation (BEC) of charged pions at $μ_{I} \geq m_{π} /2$ . With lattice results, showing some indications that the deconfinement crossover also smoothly penetrates the BEC phase, the conjecture was made that the former connects continuously to the BEC-BCS crossover. We compute the spectrum of the Dirac operator, and use generalized Banks-Casher relations, to test this conjecture and identify signatures of the superfluid BCS phase.
↳ hep-lathep-phnucl-thPoS(2022)·13 citations
09
Equation of state and neutrino transfer in supernovae and neutron stars
Kohsuke Sumiyoshi
We overview the progress of the tables of the equation of state for astrophysical simulations and the numerical methods of neutrino transfer. Hot and dense matter play essential roles in core-collapse supernovae and neutron stars. Equation of state determines the structure of compact objects and their dynamics through its behavior of thermodynamic quantities. In addition, neutrinos are trapped in supernova cores and neutron star mergers and frequently interact with matter to crucially affect dynamics in determining the explosion mechanism and the final form of compact objects. Therefore, it is essential to implement detailed processes of nuclear and neutrino physics in numerical simulations by having reliable data set of the equation of state and reaction rates. We show examples of developments of the equation of state and the neutrino transfer and discuss research directions toward understanding the explosive phenomena by the first principle calculation.
↳ astro-ph.HEnucl-thEPJA(2021)·4 citations
10
Inhomogeneous phases in the chirally imbalanced $2 + 1$ -dimensional Gross-Neveu model and their absence in the continuum limit
Laurin Pannullo🇩🇪 · Marc Wagner🇩🇪 · Marc Winstel🇩🇪
We study the $μ$ - $μ_{45}$ - $T$ phase diagram of the $2 + 1$ -dimensional Gross-Neveu model, where $μ$ denotes the ordinary chemical potential, $μ_{45}$ the chiral chemical potential and $T$ the temperature. We use the mean-field approximation and two different lattice regularizations with naive chiral fermions. An inhomogeneous phase at finite lattice spacing is found for one of the two regularizations. Our results suggest that there is no inhomogeneous phase in the continuum limit. We show that a chiral chemical potential is equivalent to an isospin chemical potential. Thus, all results presented in this work can also be interpreted in the context of isospin imbalance.
↳ hep-lathep-phnucl-thSymmetry(2022)·24 citations

Affiliations

first authorsco-authorsvia INSPIRE

Convergence of hydrodynamics in rapidly spinning strongly coupled plasma

Constraining neutron star properties with a new equation of state insensitive approach

Towards a discovery of BSM physics from the Cabibbo angle anomaly

Searching for the BCS phase at nonzero isospin asymmetry

Equation of state and neutrino transfer in supernovae and neutron stars

Inhomogeneous phases in the chirally imbalanced 2+1-dimensional Gross-Neveu model and their absence in the continuum limit

Affiliations

Inhomogeneous phases in the chirally imbalanced $2 + 1$ -dimensional Gross-Neveu model and their absence in the continuum limit