Nuclear Theory·nucl-th
22 papers—12 primary·10 cross-listed
We use the Crooks fluctuation theorem together with Zubarev hydrodynamics to develop a bottom-up theory of hydrodynamic fluctuations. We also use thermodynamic uncertainity relations to estimate bottom-up limits to dissipative transport coefficients.
Armen Sedrakian🇩🇪 · Fridolin Weber🇺🇸 · Jia-Jie Li🇩🇪
We examine the possibility that the light companion in the highly asymmetric binary compact object coalescence event GW190814 is a hypernuclear star. We use density functional theory with functionals that have been tuned to the properties of hypernuclei as well as astrophysical constraints placed by the masses of the most massive millisecond pulsars, the mass-radius range inferred from the NICER experiment, and the binary neutron star merger event GW170817. We compute general-relativistic static and maximally rotating Keplerian configurations of purely nucleonic and hypernuclear stars. We find that while nucleonic stars are broadly consistent with a neutron star being involved in GW190814, this would imply no new degrees of freedom in the dense matter up to 6.5 times the nuclear saturation density. Allowing for hyperonization of dense matter, we find that the maximal masses of hypernuclear stars, even for maximal rapidly rotating configurations, are inconsistent with a stellar nature interpretation of the light companion in GW190814, implying that this event involved two black holes rather than a neutron star and a black hole.
We present results of a detailed analysis of experimental data on the nuclear modification factor and the flow coefficient for light hadrons from RHIC for TeV Au+Au collisions and from LHC for and TeV Pb+Pb, and TeV Xe+Xe collisions. We perform calculations within the light-cone path integral approach to induced gluon emission. We use running which is frozen at low momenta at some value . We find that the RHIC data support somewhat larger value of . For the optimized values of , the theoretical predictions are in reasonable agreement with data on and . Calculations made for different formation times and life-times of the QGP show that jet quenching at the RHIC and LHC energies is only weakly sensitive to the initial and final stages of the QCD matter evolution.
Navid Abbasi🇨🇳 · Sara Tahery🇨🇳
We develop a method to study coupled dynamics of gauge-invariant variables, constructed out of metric and gauge field fluctuations on the background of a AdS Reissner-Nordström black brane. Using this method, we compute the numerical spectrum of quasinormal modes associated with fluctuations of spin 0, 1 and 2, non-perturbatively in . We also analytically compute the spectrum of hydrodynamic excitations in the small chemical potential limit. Then, by studying the spectral curve at complex momenta in every spin channel, we numerically find points at which hydrodynamic and non-hydrodynamic poles collide. We discuss the relation between such collision points and the convergence radius of the hydrodynamic derivative expansion. Specifically in the spin 0 channel, we find that within the range , the radius of convergence of the hydrodynamic sound mode is set by the absolute value of the complex momentum corresponding to the point at which the sound pole collides with the hydrodynamic diffusion pole. It shows that in holographic systems at finite chemical potential, the convergence of the hydrodynamic derivative expansion in the mentioned range is fully controlled by hydrodynamic information. As the last result, we explicitly show that the relevant information about quantum chaos in our system can be extracted from the pole-skipping points of energy density response function. We find a threshold value for , lower than which the pole-skipping points can be computed perturbatively in a derivative expansion.
S. Biswas🇫🇷 · A. Lemasson🇫🇷 · M. Rejmund🇫🇷 · A. Navin🇫🇷 · Y.H. Kim🇫🇷 · C. Michelagnoli🇫🇷 · I. Stefan🇫🇷 · R. Banik🇮🇳 · P. Bednarczyk🇵🇱 · Soumik Bhattacharya🇮🇳 · S. Bhattacharyya🇮🇳 · E. Clément🇫🇷 and 14 other authors
The fusion and transfer induced fission reaction Be(U,~f) with 6.2 MeV/u beam energy, using a unique setup consisting of AGATA, VAMOS++ and EXOGAM detectors, was used to populate through the fission process and study the neutron-rich In isotopes. This setup enabled the prompt-delayed -ray spectroscopy of isotopes in the time range of . In the odd- In isotopes, indications of a short half-life isomeric state, in addition to the previously known isomeric state, were observed from the present data. Further, new prompt transitions above the isomer in In were identified along with reevaluation of its half-life. The experimental data were compared with the theoretical results obtained in the framework of large-scale shell-model calculations in a restricted model space. The two-body matrix elements of residual interaction were modified to explain the excitation energies and the transition probabilities in the neutron-rich In isotopes. The (i) decreasing trend of in odd-In (with dominant configuration and maximum aligned spin of ) and (ii) increasing trend of in odd-Sb (with dominant configuration and maximum aligned spin of ) with increasing neutron number could be understood as a consequence of hole-hole and particle-hole interactions, respectively.
Thomas Luu🇩🇪 · Ulf-G. Meißner🇩🇪
In an earlier paper~\cite{Luu:2019jmb} we discussed emergence from the context of effective field theories, particularly as related to the fields of particle and nuclear physics. We argued on the side of reductionism and weak emergence. George Ellis has critiqued our exposition in~\cite{Ellis:2020vij}, and here we provide our response to his critiques. Many of his critiques are based on incorrect assumptions related to the formalism of effective field theories and we attempt to correct these issues here. We also comment on other statements made in his paper. Important to note is that our response is to his critiques made in archive versions arXiv:2004.13591v1-5 [physics.hist-ph]. That is, versions 1-5 of this archive post. Version 6 has similar content as versions 1-5, but versions 7-9 are seemingly a different paper altogether (even with a different title).
L. Ma. Y. G. Ma · S. Zhang
In the framework of a multi-phase transport model, fluctuation and correlation of the azimuthal anisotropies in C+Au collisions at = 200 GeV are explored. Properties of the initial eccentricity and final harmonic flow fluctuation resulted from C+Au collisions with Woods-Saxon configuration and triangular -clustering configurations of C are investigated via scaled variance, skewness and kurtosis. Comparisons are made between results from -clustered configurations and Woods-Saxon configuration. The triangular flow fluctuation is found to have particular sensitivity in distinguishing triangular -clustering structure of C. Furthermore, correlations between initial eccentricities and final flow harmonics are studied with strong multiplicity dependence observed for the correlation functions.
Sukrit Jaiswal · Debarati Chatterjee
In this undergraduate project, f-mode oscillations in neutron stars are used to constrain the equation of state of dense matter. For the first time, a systematic investigation of the role of nuclear saturation parameters on the mode oscillations is performed. It is found that the uncertainty in the determination of effective nucleon mass plays the most significant role in controlling the f-mode frequencies. Correlations of the frequencies with astrophysical observables relevant for asteroseismology are also investigated. Future detection of f-mode frequencies could then provide a unique way of constraining nuclear empirical parameters and therefore the behaviour of dense matter.
Nora Brambilla🇩🇪 · Viljami Leino🇩🇪 · Peter Petreczky🇺🇸 · Antonio Vairo🇩🇪
We report progress towards computing the heavy quark momentum diffusion coefficient from the correlator of two chromo-electric fields attached to a Polyakov loop in pure SU(3) gauge theory. Using a multilevel algorithm and tree-level improvement, we study the behavior of the diffusion coefficient as a function of temperature in the wide range in order to compare it to perturbative expansions at high temperature. We find that within errors the lattice results are remarkably compatible with the next-to-leading order perturbative result.
Ajaharul Islam🇺🇸 · Michael Strickland🇺🇸
We compute the suppression and elliptic flow of bottomonium using real-time solutions to the Schrödinger equation with a realistic in-medium complex-valued potential. To model the initial production, we assume that, in the limit of heavy quark masses, the wave-function can be described by a lattice-smeared (Gaussian) Dirac delta wave-function. The resulting final-state quantum-mechanical overlaps provide the survival probability of all bottomonium eigenstates. Our results are in good agreement with available data for as a function of and collected at 5.02 TeV. In the case of for the various states, we find that the path-length dependence of suppression results in quite small for . Our prediction for the integrated elliptic flow for in the % centrality class is . We additionally find that, due to their increased suppression, excited bottomonium states have a larger elliptic flow and we make predictions for and as a function of centrality and transverse momentum. Similar to prior studies, we find that it is possible for bottomonium states to have negative at low transverse momentum.
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