Frankfurt Institute for Advanced Studies

About: Frankfurt Institute for Advanced Studies is a facility organization based out in Frankfurt am Main, Germany. It is known for research contribution in the topics: Baryon & Quark–gluon plasma. The organization has 798 authors who have published 2733 publications receiving 82799 citations. The organization is also known as: FIAS.

Universal functions of nuclear proximity potential for Skyrme nucleus-nucleus interaction in a semiclassical approach

Abstract: The universal function of the nuclear proximity potential is obtained for the Skyrme nucleus–nucleus interaction in the semiclassical extended Thomas–Fermi (ETF) approach. This is obtained as a sum of the spin–orbit-density-independent and spin–orbit-density-dependent parts of the Hamiltonian density, since the two terms behave differently, the spin–orbit-density-independent part mainly attractive and the spin-orbit-density-dependent part mainly repulsive. The semiclassical expansions of kinetic energy density and spin–orbit density are allowed up to second order, and the two-parameter Fermi density, with its parameters fitted to experiments, is used for the nuclear density. The universal functions or the resulting nuclear proximity potential reproduce the 'exact' Skyrme nucleus–nucleus interaction potential in the semiclassical approach, within less than ~1 MeV of difference, both at the maximum attraction and in the surface region. An application of the resulting interaction potential to fusion excitation functions shows clearly that the parameterized universal functions of nuclear proximity potential substitute completely the 'exact' potential in the Skyrme energy density formalism based on the semiclassical ETF method, including also the modifications of interaction barriers at sub-barrier energies in terms of modifying the constants of the universal functions.

Many-body Forces in the Equation of State of Hyperonic Matter

Abstract: In this work we introduce an extended version of the formalism proposed originally by Taurines et al. that considers the effects of many-body forces simulated by nonlinear self-couplings and meson–meson interaction contributions. In this extended version of the model, we assume that matter is at zero temperature, charge neutral, and in beta-equilibrium, considering that the baryon octet interacts by the exchange of scalar–isoscalar (σ, ), vector–isoscalar (ω, ϕ), vector–isovector (), and scalar–isovector (δ) meson fields. Using nuclear matter properties, we constrain the parameters of the model that describe the intensity of the indirectly density dependent baryon–meson couplings to a small range of possible values. We then investigate asymmetric hyperonic matter properties. We report that the formalism developed in this work is in reasonable agreement with experimental data and also allows for the existence of massive hyperon stars (with more than ) with small radii, compatible with astrophysical observations.

Constraining compact star properties with nuclear saturation parameters

Abstract: A set of hadronic equations of state (EoSs) derived from relativistic density-functional theory and constrained by terrestrial experiments, astrophysical observations, in particular by the GW170817 event, and chiral effective field theory $(\ensuremath{\chi}\mathrm{EFT})$ of neutron matter is used to explore the sensitivity of the EoS parameterization on the few nuclear-matter characteristics defined at the saturation density. We find that the gross properties of compact stars are most sensitive to the isoscalar skewness coefficient ${Q}_{\text{sat}}$ and the isovector slope coefficient ${L}_{\text{sym}}$ around saturation density, since the higher-order coefficients, such as ${K}_{\text{sym}}$, are fixed by our model. More specifically, (i) among these ${Q}_{\text{sat}}$ is the dominant parameter controlling both the maximum mass and the radii of compact stars while ${L}_{\mathrm{sym}}$ is constrained somewhat by $\ensuremath{\chi}\mathrm{EFT}$ of neutron matter, (ii) massive-enough $(M\ensuremath{\sim}2.0\phantom{\rule{0.16em}{0ex}}{M}_{\ensuremath{\bigodot}})$ compact stars featuring both hyperons and $\mathrm{\ensuremath{\Delta}}$ resonances can be obtained if the value of ${Q}_{\text{sat}}$ is large enough, and (iii) the emergence of $\mathrm{\ensuremath{\Delta}}$'s reduces the radius of a canonical mass $(M\ensuremath{\sim}1.4\phantom{\rule{0.16em}{0ex}}{M}_{\ensuremath{\bigodot}})$ compact star thus easing the tension between the predictions of the relativistic density functionals and the inferences from the x-ray observation of nearby isolated neutron stars.

Universal Flow-Driven Conical Emission in Ultrarelativistic Heavy-Ion Collisions

Abstract: The double-peak structure observed in soft-hard hadron correlations is commonly interpreted as a signature for a Mach cone generated by a supersonic jet interacting with the hot and dense medium created in ultrarelativistic heavy-ion collisions. We show that it can also arise due to averaging over many jet events in a transversally expanding background. We find that the jet-induced away-side yield does not depend on the details of the energy-momentum deposition in the plasma, the jet velocity, or the system size. Our claim can be experimentally tested by comparing soft-hard correlations induced by heavy-flavor jets with those generated by light-flavor jets.