Nuclear Theory·nucl-th

Thursday·March 29, 2018

7 papers—4 primary·3 cross-listed

01
Theoretical uncertainties of the elastic nucleon-deuteron scattering observables
R.Skibinski · Yu.Volkotrub · J.Golak · K.Topolnicki · H.Witala
Theoretical uncertainties of various types are discussed for the nucleon-deuteron elastic scattering observables at the incoming nucleon laboratory energies up to 200 MeV. We are especially interested in the statistical errors arising from uncertainties of parameters of a nucleon-nucleon interaction. The obtained uncertainties of the differential cross section and numerous scattering observables are in general small, grow with the reaction energy and amount up to a few percent at 200 MeV. We compare these uncertainties with the other types of theoretical errors like truncation errors, numerical uncertainties and uncertainties arising from using the various models of nuclear interaction. We find the latter ones to be dominant source of uncertainties of modern predictions for the three-nucleon scattering observables. To perform above mentioned studies we use the One-Pion-Exchange Gaussian potential derived by the Granada group, for which the covariance matrix of its parameters is known, and solve the Faddeev equation for the nucleon-deuteron elastic scattering. Thus beside studying theoretical uncertainties we also show a description of the nucleon-deuteron elastic scattering data by the One-Pion-Exchange Gaussian model and compare it with results obtained with other nucleon-nucleon potentials, including chiral N $^{4}$ LO forces from the Bochum-Bonn and Moscow(Idaho)-Salamanca groups. In this way we confirm the usefulness and high quality of the One-Pion-Exchange Gaussian force.
nucl-thPRC(2018)·16 citations
02
Influence of anisotropic $Λ/Σ$ creation on the $Ξ^{-}$ mutiplicity in subthreshold proton-nucleus collisions
Miklós Zétényi🇭🇺 · György Wolf🇭🇺
We present an analysis of $Ξ^{-}$ baryon production in subthreshold proton--nucleus ( $p + A$ ) collisions in the framework of a BUU type transport model. We propose a new mechanism for $Ξ$ production in the collision of a secondary $Λ$ or $Σ$ hyperon and a nucleon from the target nucleus. We find that the $Ξ^{-}$ multiplicity in $p + A$ collisions is sensitive to the angular distribution of hyperon production in the primary $N + N$ collision. Using reasonable assumptions on the unknown elementary cross sections we are able to reproduce the $Ξ^{-}$ multiplicity and the $Ξ^{-} / (Λ + Σ^{0})$ ratio obtained in the HADES experiment in $p$ +Nb collisions at $s_{N N} =$ 3.2 GeV energy.
nucl-thnucl-exPLB(2018)·11 citations
03
Addendum to Strangeness Production and Color Deconfinement
P. Castorina🇮🇹 · S. Plumari🇮🇹 · H. Satz🇩🇪
Recent extensive data from the beam energy scan of the STAR collaboration at BNL-RHIC provide the basis for a detailed update for the universal behavior of the strangeness suppression factor gamma_s as function of the initial entropy density, as proposed in our recent paper [1]. [1] P. Castorina, S. Plumari and H. Satz, Int. J. Mod. Phys. E26 (2017) 1750081 (arXiv:1709.02706)
nucl-thhep-phIJMPE(2017)·15 citations
04
Quantum Monte Carlo formalism for dynamical pions and nucleons
Lucas Madeira🇺🇸 · Alessandro Lovato🇮🇹 · Francesco Pederiva🇮🇹 · Kevin E. Schmidt🇺🇸
In most simulations of nonrelativistic nuclear systems, the wave functions found solving the many-body Schrödinger equations describe the quantum-mechanical amplitudes of the nucleonic degrees of freedom. In those simulations the pionic contributions are encoded in nuclear potentials and electroweak currents, and they determine the low-momentum behavior. In this work we present an alternative quantum Monte Carlo formalism in which both relativistic pions and nonrelativistic nucleons are explicitly included in the quantum-mechanical states of the system. We report the renormalization of the nucleon mass as a function of the momentum cutoff, an Euclidean time density correlation function that deals with the short-time nucleon diffusion, and the pion cloud density and momentum distributions. In the two-nucleon sector we show that the interaction of two static nucleons at large distances reduces to the one-pion exchange potential, and we fit the low-energy constants of the contact interactions to reproduce the binding energy of the deuteron and two neutrons in finite volumes. We show that the method can be readily applied to light-nuclei.
nucl-thPRC(2018)·12 citations
05
Study of Isolated-photon and Jet Momentum Imbalance in $pp$ and $P b P b$ collisions
Lin Chen🇨🇳 · Guang-You Qin🇨🇳 · Lei Wang🇨🇳 · Shu-Yi Wei🇫🇷 · Bo-Wen Xiao🇨🇳 · Han-Zhong Zhang🇨🇳 · Ya-Qi Zhang🇨🇳
In this paper, we study the production of isolated-photon plus a jet in $pp$ and $P b P b$ collisions, which can be used as an important probe to the jet transport property in quark gluon plasma created in heavy ion collisions. Normally, there are two types of observables associated with the production of isolated-photon plus a jet, namely, the azimuthal angular correlation and the transverse momentum imbalance. To understand both observables in the full kinematical region, we need to employ the perturbative QCD calculation, which takes into account the hard splitting of partons, together with the Sudakov resummation formalism, which resums soft gluon splittings. Furthermore, by introducing energy-loss into the system, we calculate the enhancement of the momentum imbalance distribution for $AA$ as compared to $pp$ collisions and make predictions for future unfolded experimental data. In addition, in order to extract the jet transport coefficient more precisely in our numerical calculation, we also distinguish quark jets from gluon jets, since they interact with quark gluon plasma with different strengths. This work provides a reliable theoretical tool for the calculation of the gamma-jet correlation, which can lead us to a more precise extraction of the jet transport coefficient in relativistic heavy-ion collisions.
↳ hep-phnucl-exnucl-thNPB(2018)·34 citations
06
Covariant interacting Hadron-Resonance Gas model
Thorsten Steinert🇩🇪 · Wolfgang Cassing🇩🇪
The Hadron-Resonance Gas (HRG) approach - used to model hadronic matter at small baryon potentials $μ_{B}$ and finite temperature $T$ - is extended to finite and large chemical potentials by introducing interactions between baryons in line with relativistic mean-field theory defining an interacting HRG (IHRG). Using lattice data for $μ_{B} = 0$ as well as information on the nuclear equation of state at $T = 0$ we constrain the attractive and repulsive interactions of the IHRG such that it reproduces the lattice equation of state at $μ_{B} = 0$ and the nuclear equation of state at $T = 0$ and finite $μ_{B}$ . The formulated covariant approach is thermodynamically consistent and allows us to provide further information on the phase boundary between hadronic and partonic phases of strongly interacting matter by assuming constant thermodynamic potentials.
↳ hep-phnucl-thPRC(2018)·11 citations
07
Photonuclear Reactions in Astrophysics
T. Rauscher
A brief overview of the importance of photodisintegration reactions in astrophysical environments is given and the relevance of photonuclear experiments for nucleosynthesis studies is discussed.
↳ astro-ph.HEnucl-exnucl-thNucl.Phys.News(2018)·11 citations

Affiliations

first authorsco-authorsvia INSPIRE

Theoretical uncertainties of the elastic nucleon-deuteron scattering observables

Influence of anisotropic Λ/Σ creation on the Ξ− mutiplicity in subthreshold proton-nucleus collisions

Addendum to Strangeness Production and Color Deconfinement

Quantum Monte Carlo formalism for dynamical pions and nucleons

Study of Isolated-photon and Jet Momentum Imbalance in pp and PbPb collisions

Covariant interacting Hadron-Resonance Gas model

Photonuclear Reactions in Astrophysics

Affiliations

Influence of anisotropic $Λ/Σ$ creation on the $Ξ^{-}$ mutiplicity in subthreshold proton-nucleus collisions

Study of Isolated-photon and Jet Momentum Imbalance in $pp$ and $P b P b$ collisions