Nuclear Theory·nucl-th

Wednesday·February 17, 2021

8 papers—4 primary·4 cross-listed

01
On the QED corrections to elastic electron scattering at high momentum transfer
D.H.Jakubassa-Amundsen
Estimates of QED and dispersion effects on the cross section for elastic electron scattering from a 12C nucleus are provided for collision energies in the range of 120-450 MeV. While in general such corrections are smoothly varying with energy or scattering angle, they show structures in the vicinity of diffraction minima which are very sensitive to details of the theoretical models. This casts doubt on the assertion that the discrepancy between QED background-corrected experimental data and theory in these minima originates solely from dispersion.
nucl-th3 citations
02
Accessing the shape of atomic nuclei with relativistic collisions of isobars
Giuliano Giacalone🇩🇪 · Jiangyong Jia🇺🇸 · Vittorio Somà🇫🇷
Nuclides sharing the same mass number (isobars) are observed ubiquitously along the stability line. While having nearly identical radii, stable isobars can differ in shape, and present in particular different quadrupole deformations. We show that even small differences in these deformations can be probed by relativistic nuclear collisions experiments, where they manifest as deviations from unity in the ratios of elliptic flow coefficients taken between isobaric systems. Collider experiments with isobars represent, thus, a unique means to obtain quantitative information about the geometric shape of atomic nuclei.
nucl-thhep-exhep-phnucl-exPRC(2021)·52 citations
03
Semiclassical propagator approach for emission processes. I. Two body non-relativistic case
S.A. Ghinescu · D.S. Delion
We compare the coupled channels procedure to the semiclassical approach to describe two-body emission processes, in particular $α$ -decay, from deformed nuclei within the propagator method. We express the scattering amplitudes in terms of a propagator matrix, describing the effect of the deformed field, multiplied by the ratio between internal wave function components and irregular Coulomb waves. In the spherical case the propagator becomes diagonal and scattering amplitudes acquire the well-known form. We describe a more rigorous formulation of the 3D semiclassical approach, corresponding to deformed potentials, which leads to the exact results and we also compare them with the much simpler expressions given by the Angular Wentzel-Krames-Brillouin (AWKB) and Linearized WKB (LWKB) with its approximation, known as Fröman WKB (FWKB) method. We will show that LWKB approach is closer than AWKB to the exact coupled-channels formalism. An analysis of alpha-emission from ground states of even-even nuclei evidences the important role played by deformation upon the channel decay widths.
nucl-th0 citations
04
Variational theory combining number-projected BCS and coupled-cluster doubles
V. V. Baran · J. Dukelsky
The ground state pairing correlations in finite fermionic systems are described with a high degree of accuracy within a variational approach based on a combined coupled-cluster and particle-number-projected BCS ansatz. The flexibility of this symmetry-preserving wavefunction enables a unified picture valid from weak to strong coupling, both in small and large systems. The present variational approach consistently yields an energy upper bound while operating at the same level of precision of the non-variational particle-number projected Bogoliubov-coupled-cluster theory [Phys. Rev. C 99, 044301 (2019)].
nucl-thcond-mat.supr-conPRC(2021)·5 citations
05
Proton mass decomposition: naturalness and interpretations
Xiangdong Ji🇺🇸
I discuss the scope and naturalness of the proton mass decomposition (or sum rule) published in PRL74, 1071 (1995) and answer a few criticisms that appeared recently in the literature, focusing particularly on its interpretation and the quantum anomalous energy contribution. I comment on the so-called frame-independent or invariant-mass decomposition from the trace of the energy-momentum tensor. I stress the importance of measuring the quantum anomalous energy through experiments. Finally, I point out a large discrepancy in the scalar radius of the nucleon extracted from vector-meson productions and lattice QCD calculations.
↳ hep-phhep-latnucl-exnucl-thFront.Phys.(Beijing)(2021)·104 citations
06
Rapidity dependence of heavy-flavour production in heavy-ion collisions within a full 3+1 transport approach: quenching, elliptic and directed flow
Andrea Beraudo🇮🇹 · Arturo De Pace🇮🇹 · Marco Monteno🇮🇹 · Marzia Nardi🇮🇹 · Francesco Prino🇮🇹
We extend our POWLANG transport setup for the modelling of heavy-flavour production in heavy-ion collisions to the case of full 3+1 simulations, dropping the approximation of longitudinal boost-invariance of the background medium. This enables us to provide predictions for observables for which the rapidity dependence is essential in order to obtain a non-vanishing signal, like the directed flow $v_{1}$ , and to get reliable results also for kinematic distributions of heavy-flavour particles at forward rapidity. We compare our predictions with experimental data obtained in Au-Au and Pb-Pb collisions at RHIC and at the LHC.
↳ hep-phnucl-exnucl-thJHEP(2021)·32 citations
07
Diffusion coefficient matrix of the strongly interacting quark-gluon plasma
Jan A. Fotakis🇩🇪 · Olga Soloveva🇩🇪 · Carsten Greiner🇩🇪 · Olaf Kaczmarek🇩🇪 · Elena Bratkovskaya🇩🇪
We study the diffusion properties of the strongly interacting quark-gluon plasma (sQGP) and evaluate the diffusion coefficient matrix for the baryon ( $B$ ), strange ( $S$ ) and electric ( $Q$ ) charges - $κ_{q q^{'}}$ ( $q, q^{'} = B, S, Q$ ) and show their dependence on temperature $T$ and baryon chemical potential $μ_{B}$ . The non-perturbative nature of the sQGP is evaluated within the Dynamical Quasi-Particle Model (DQPM) which is matched to reproduce the equation of state of the partonic matter above the deconfinement temperature $T_{c}$ from lattice QCD. The calculation of diffusion coefficients is based on two methods: i) the Chapman-Enskog method for the linearized Boltzmann equation, which allows to explore non-equilibrium corrections for the phase-space distribution function in leading order of the Knudsen numbers as well as ii) the relaxation time approximation (RTA). In this work we explore the differences between the two methods. We find a good agreement with the available lattice QCD data in case of the electric charge diffusion coefficient (or electric conductivity) at vanishing baryon chemical potential as well as a qualitative agreement with the recent predictions from the holographic approach for all diagonal components of the diffusion coefficient matrix. The knowledge of the diffusion coefficient matrix is also of special interest for more accurate hydrodynamic simulations.
↳ hep-phnucl-thPRD(2021)·37 citations
08
EIC Physics from An All-Silicon Tracking Detector
John Arrington🇺🇸 · Reynier Cruz-Torres🇺🇸 · Winston DeGraw🇺🇸 · Xin Dong🇺🇸 · Leo Greiner🇺🇸 · Samuel Heppelmann🇺🇸 · Barbara Jacak🇺🇸 · Yuanjing Ji🇺🇸 · Matthew Kelsey🇺🇸 · Spencer R. Klein🇺🇸 · Yue Shi Lai🇺🇸 · Grazyna Odyniec🇺🇸 and 8 other authors
The proposed electron-ion collider has a rich physics program to study the internal structure of protons and heavy nuclei. This program will impose strict requirements on detector design. This paper explores how these requirements can be satisfied using an all-silicon tracking detector, by consideration of three representative probes: heavy flavor hadrons, jets, and exclusive vector mesons.
↳ nucl-exnucl-th22 citations

Affiliations

first authorsco-authorsvia INSPIRE