Nuclear Theory·nucl-th

Tuesday·February 18, 2020

14 papers—8 primary·6 cross-listed

01
GW170817 constraints analyzed with Gogny forces and momentum-dependent interactions
O. Lourenço · M. Bhuyan · C. H. Lenzi · M. Dutra · C. Gonzalez-Boquera · M. Centelles · X. Viñas
A set of equations of state obtained from finite-range Gogny forces and momentum-dependent interactions is used to investigate the recent observation of gravitational waves from the binary neutron star merger GW170817 event. For this set of interactions, we have calculated the neutron star tidal deformabilities (related to the second Love number), the mass-radius diagram, and the moment of inertia~( $I$ ). The $I$ -Love relation has been verified. We also have found strong correlations among the tidal deformability of the canonical neutron star, its radius, and the derivatives of the nuclear symmetry energy at the saturation density. Most of the obtained results are located within the constraints of the tidal deformabilities extracted from the GW170817 detection.
nucl-thPLB(2020)·21 citations
02
On the light-front wave functions of quarkonia
Pieter Maris🇺🇸 · Shaoyang Jia🇺🇸 · Meijian Li🇺🇸 · Yang Li🇺🇸 · Shuo Tang🇺🇸 · James P. Vary🇺🇸
The light-front wave functions of hadrons allow us to calculate a wide range of physical observables; however, the wave functions themselves cannot be measured. We discuss recent results for quarkonia obtained in basis light-front quantization using an effective Hamiltonian with a confining model in both the transverse and longitudinal directions and with explicit one-gluon exchange. In particular, we focus on the numerical convergence of the basis expansion, as well as the asymptotic behavior of the light-front wave functions. We also illustrate that, for mesons with unequal quark masses, the maxima of the light-front wave functions depend in a non-trivial way on the valence quark-mass difference.
nucl-thhep-phPoS(2020)·4 citations
03
$_{ΛΛ}^{5}$ H and $_{ΛΛ}^{5}$ He Hypernuclei reexamined in Halo/Cluster Effective Theory
Ghanashyam Meher🇮🇳 · Udit Raha🇮🇳
The J=1/2 iso-doublet double- $Λ$ -hypernuclei, namely, $_{ΛΛ}^{5}$ H and $_{ΛΛ}^{5}$ He, are examined as the three-body cluster states, $ΛΛ t$ ( $t \equiv^{3}$ H or triton) and $ΛΛ h$ ( $h \equiv^{3}$ He or helion), respectively, in a model independent framework utilizing pionless halo effective theory. Both singlet and triplet states of the constituent $Λ T$ ( $T \equiv t, h$ ) sub-system are used in the elastic channel for the study of $_{Λ}^{4}$ H $- Λ$ and $_{Λ}^{4}$ He $- Λ$ scattering processes. A prototypical leading order investigation using a sharp momentum cut-off regulator, irrespective of the type of the elastic channel chosen, yields almost identical cut-off dependence of the three-body binding energy or the double- $Λ$ -separation energy ( $B_{ΛΛ}$ ) is obtained for the mirror partners, evidently suggesting good isospin symmetry in these three-body systems. Subsequently, upon normalization of our solutions to the integral equation with respect to a single pair of input data from an {\it ab initio} potential model analysis for each mirror hypernuclei, yields $B_{ΛΛ}$ which agrees fairly well with various erstwhile regulator independent potential models for our choice of the cut-off regulator, $\sim 200$ MeV. This is either consistent with pionless effective theory or with its slightly augmented version with a hard scale around $2 m_{π}$ , where low-energy $Λ$ - $Λ$ interactions dominated by $π π$ or $σ$ -meson exchange. Finally, to demonstrate the predictability of our effective theory, we present preliminary estimates of the S-wave $ΛΛ T$ three-body scattering lengths and the $Λ$ -separation energies.
nucl-thPRC(2021)·4 citations
04
Neutron star matter equation of state including $d^{*}$ -hexaquark degrees of freedom
A. Mantziris🇬🇧 · A. Pastore🇬🇧 · I. Vidaña🇮🇹 · D. P. Watts🇬🇧 · M. Bashkanov🇬🇧 · A. M. Romero🇬🇧
We present an extension of a previous work where, assuming a simple free bosonic gas supplemented with a relativistic meand field model to describe the pure nucleonic part of the EoS, we studied the consequences that the first non-trivial hexaquark $d^{*}$ (2380) could have on the properties of neutron stars. Compared to that exploratory work we employ a standard non-linear Walecka model including additional terms that describe the interaction of the $d^{*} (2380)$ di-baryon with the other particles of the system through the exchange of $σ$ - and $ω$ -meson fields. Our results have show that the presence of the $d^{*} (2380)$ leads to maximum masses compatible with the recent observations of $\sim 2$ M $_{⊙}$ millisecond pulsars if the interaction of the $d^{*} (2380)$ is slightly repulsive or the $d^{*} (2380)$ does not interacts at all. An attractive interaction makes the equation of state too soft to be able to support a $2$ M $_{⊙}$ neutron star whereas an extremely repulsive one induces the collapse of the neutron star into a black hole as soon as the $d^{*} (2380)$ appears.
nucl-thnucl-exAstron.Astrophys.(2020)·10 citations
05
Multi-stage evolution of heavy quarks in the quark-gluon plasma
G. Vujanovic🇺🇸 · A. Angerami · S. A. Bass · S. Cao · Y. Chen · J. Coleman · L. Cunqueiro · T. Dai · L. Du · R. Ehlers · H. Elfner · D. Everett and 38 other authors
The interaction of heavy flavor with the quark-gluon plasma (QGP) in relativistic heavy-ion collisions is studied using JETSCAPE, a publicly available software package containing a framework for Monte Carlo event generators. Multi-stage (and multi-model) evolution of heavy quarks within JETSCAPE provides a cohesive description of heavy flavor quenching inside the QGP. As the parton shower develops, a model becomes active as soon as its kinematic region of validity is reached. Two combinations of heavy-flavor energy-loss models are explored within a realistic QGP medium, using parameters which were tuned to describe {\it light-flavor} partonic energy-loss.
nucl-thhep-phNPA(2021)·8 citations
06
Description of the reactions 36S + 238U and 64Ni + 238U within the two-stage fusion-fission model
V.L. Litnevsky · F.A. Ivanyuk · G.I. Kosenko · S. Chiba
We describe the capture, fusion, fission and evaporation residue formation cross sections of superheavy nuclei within the proposed earlier two stages dynamical model. The approaching of the projectile nucleus to the target nucleus is described in the first stage of the model. On the second stage, the evolution of the system formed after the touching of the projectile and target nuclei is considered. The evolution of the system on both stages is described by Langevin equations. The transport coefficients of these equations are calculated within the microscopic linear response theory. The mutual orientation of the colliding ions, the tunneling through the Coulomb barrier in the entrance channel and the shell effects in the potential energy on both stages of the calculations are taking into account. The obtained results are compared with the available experimental data and other theoretical predictions.
nucl-thPRC(2020)·13 citations
07
Effects of initial state fluctuations on the mean transverse momentum
Fernando G. Gardim🇧🇷 · Giuliano Giacalone🇫🇷 · Matthew Luzum🇧🇷 · Jean-Yves Ollitrault🇫🇷
We show that in ideal hydrodynamic simulations of heavy-ion collisions, initial state fluctuations result in an increase of the mean transverse momentum of outgoing hadrons, $⟨ p_{t} ⟩$ . Specifically, $⟨ p_{t} ⟩$ is larger by a few percent if realistic fluctuations are implemented than with smooth initial conditions, the multiplicity and impact parameter being kept fixed. We show that result can be traced back to the fact that for a given total entropy, the initial energy contained in the fluid is larger if the density profile is bumpy. We discuss the implication of these results for the extraction of the equation of state of QCD from experimental data.
nucl-thhep-phnucl-exNPA(2021)·26 citations
08
Jet quenching in a multi-stage Monte Carlo approach
A. Kumar🇺🇸 · A. Angerami · S. A. Bass · S. Cao · Y. Chen · J. Coleman · L. Cunqueiro · T. Dai · L. Du · R. Ehlers · H. Elfner · D. Everett and 38 other authors
We present a jet quenching model within a unified multi-stage framework and demonstrate for the first time a simultaneous description of leading hadrons, inclusive jets, and elliptic flow observables which spans multiple centralities and collision energies. This highlights one of the major successes of the JETSCAPE framework in providing a tool for setting up an effective parton evolution that includes a high-virtuality radiation dominated energy loss phase (MATTER), followed by a low-virtuality scattering dominated (LBT) energy loss phase. Measurements of jet and charged-hadron $R_{AA}$ set strong constraints on the jet quenching model. Jet-medium response is also included through a weakly-coupled transport description.
nucl-thhep-phnucl-exNPA(2021)·11 citations

Affiliations

first authorsco-authorsvia INSPIRE