Nuclear Theory·nucl-th

Wednesday·November 17, 2021

10 papers—6 primary·4 cross-listed

07
Resurrecting the Strong KSS Conjecture
Scott Lawrence🇺🇸
Many counterexamples to the proposed KSS bound $\frac{η}{s} \geq \frac{1}{4 π}$ depend on constructing systems with large numbers of species. As a result, the entropy density grows large and $\frac{η}{s}$ can be made arbitrarily small. However, these constructions do not affect the dimensionless shear viscosity $\frac{η T}{ϵ + P}$ , which agrees with the traditional $\frac{η}{s}$ only for vanishing chemical potential. This raises the possibility that a KSS-like bound holds for all systems, not just UV-complete quantum field theories, contrary to the previous understanding.
↳ hep-thnucl-th3 citations
08
Spectral functions of heavy quarkonia in a bulk-viscous quark gluon plasma
Lata Thakur🇰🇷 · Yuji Hirono🇰🇷
We study the properties of quarkonia inside a bulk-viscous quark gluon plasma. The non-equilibrium nature of the medium is encoded in the deformed distribution functions of thermal quarks and gluons, with which we compute the dielectric permittivity within the hard thermal loop approximation at one-loop. The modified dielectric permittivity is used to calculate the in-medium heavy quark potential, and using the potential we compute spectral functions, which reflect the physical properties of heavy quarkonia. We discuss how the bulk viscous effect influences quantities such as binding energies and thermal widths. Based on those properties, we discuss the implications of the bulk viscous effect on the physical observables such as $ψ^{'}$ to $J / ψ$ ratio and the nuclear modification factor, $R_{AA}$ . In particular, we argue that the nuclear modification factors of excited and ground states show different sensitivities to the bulk viscous nature of a plasma, which is potentially useful for the critical point search.
↳ hep-phhep-exnucl-thJHEP(2022)·14 citations
09
Neutrino flavor evolution in dense environments and the r-process
Maria Cristina Volpe🇫🇷
In dense environments, standard and non-standard neutrino interactions with the background particles trigger a variety of flavor mechanisms, which can impact r-process nucleosynthetic abundances. Future observations of a(n) (extra)galactic supernova will tell us about properties of neutrinos and of the astrophysical source that produce them. The upcoming measurement of the diffuse supernova neutrino background constitute a unique source of information. We highlight some recent developments.
↳ hep-phastro-ph.SRnucl-thPoS(2022)·0 citations
10
Quantum mechanics of radiofrequency-driven coherent beam oscillations in storage rings
J. Slim🇩🇪 · N.N. Nikolaev🇷🇺 · F. Rathmann🇩🇪 · A. Wirzba🇩🇪
Precision searches for the electric dipole moment of protons in storage ring experiments call for beam-position monitoring in the picometer range. We present the relevant fully quantum mechanical derivation of radiofrequency-driven collective oscillations of a beam in a storage ring.
↳ physics.acc-phhep-phnucl-exnucl-th+1Phys.Rev.Accel.Beams(2023)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

Resurrecting the Strong KSS Conjecture

Spectral functions of heavy quarkonia in a bulk-viscous quark gluon plasma

Neutrino flavor evolution in dense environments and the r-process

Quantum mechanics of radiofrequency-driven coherent beam oscillations in storage rings

Affiliations