Nuclear Theory·nucl-th

Tuesday·June 29, 2021

10 papers—3 primary·7 cross-listed

04
Toward precision jet event shape for future Electron-Ion Collider
Daekyoung Kang🇨🇳 · Tanmay Maji🇨🇳
We present angularity differential cross-section for the deep inelastic scattering process (DIS) in the framework of soft-collinear effective theory (SCET). Using SCET, the cross-section is factorized in terms of hard, jet, beam and soft functions. Our result includes resummation of the large logarithms up to next-to-next leading logarithmic (NNLL) accuracy. The numerical results presented here for DIS angularity cross-section can be explored by the future EIC.
↳ hep-phnucl-thPoS(2019)·5 citations
05
Monte Carlo simulations of the S-shaped neutron guides with asymmetric concave and convex surface coatings
Alexandre P.S. Souza🇧🇷 · Luiz P. de Oliveira🇧🇷 · Frederico A. Genezini🇧🇷
During the last decades, neutron beam transportation has been a well-known and established subject for designing proper neutron guides. However, sometimes unusual adaptation or adjustments are required out of original projects and after operation beginning of facilities. Inter-center transferring of instrument locations also requires a new approach that is not necessarily described in the literature. Inside these situations, the use of S-shaped guides has not been fully discussed in the literature. From a geometrical analysis, we develop a formalism of construction of a minimal S-shaped guide by only considering the exclusion of the Line-of-Sight. We study this guide model through the wavelength cutoff and the neutron transport efficiency analysis. Here, Monte Carlo simulations using MCSTAS software are applied. By intending to optimize these guide systems, simulations of this study also consider scenarios that have different supermirrors. A formalism to determine wavelength cutoff for unique and variable index guide systems is also developed. Simulation results show a good agreement between theoretical and simulated wavelength cutoff values. In addition, we have found specific configurations that combine efficient neutron transport and lower index values on the convex surfaces of curved guides that form the S-shaped guide.
↳ physics.ins-detnucl-exnucl-thquant-phNucl.Instrum.Meth.A(2022)·2 citations
06
"Smashing more than two": Deuteron production in relativistic heavy ion collisions via stochastic multi-particle reactions
Jan Staudenmaier🇩🇪 · Dmytro Oliinychenko🇺🇸 · Juan M. Torres-Rincon🇩🇪 · Hannah Elfner🇩🇪
We study the deuteron production via the deuteron pion and nucleon catalysis reactions, $π p n \leftrightarrow π d$ and $N p n \leftrightarrow N d$ , by employing stochastic multi-particle reactions in the hadronic transport approach SMASH for the first time. This is an improvement compared to previous studies, which introduced an artificial fake resonance $d^{'}$ to simulate these $3 \leftrightarrow 2$ reactions as a chain of $2 \leftrightarrow 2$ reactions. The derivation of the stochastic criterion for multi-particle reactions is presented in a comprehensive fashion and its implementation is tested against an analytic expression for the scattering rate and the equilibrating particle yields in box calculations. We then study Au + Au collisions at $s_{NN} = 7.7$ GeV, where we find that multi-particle collisions substantially reduce the time required for deuterons to reach partial chemical equilibrium with nucleons. Subsequently, the final yield of $d$ is practically independent from the number of $d$ at particlization, confirming the results of previous studies. The mean transverse momentum and the integrated elliptic flow as a function of centrality are rather insensitive to the exact realization of the $2 \leftrightarrow 3$ reactions.
↳ hep-phnucl-thPRC(2021)·67 citations
07
Hadron gas in the presence of a magnetic field using non-extensive statistics: A transition from diamagnetic to paramagnetic system
Girija Sankar Pradhan🇮🇳 · Dushmanta Sahu🇮🇳 · Suman Deb🇮🇳 · Raghunath Sahoo🇮🇳
Non-central heavy-ion collisions at ultra-relativistic energies are unique in producing magnetic fields of the largest strength in the laboratory. Such fields being produced at the early stages of the collision could affect the properties of Quantum Chromodynamics (QCD) matter formed in the relativistic heavy-ion collisions. The transient magnetic field leaves its reminiscence, which in principle, can affect the thermodynamic and transport properties of the final state dynamics of the system. In this work, we study the thermodynamic properties of a hadron gas in the presence of an external static magnetic field using a thermodynamically consistent non-extensive Tsallis distribution function. Various thermodynamical observables such as energy density ( $ϵ$ ), entropy density ( $s$ ), pressure ( $P$ ) and speed of sound ( $c_{s}$ ) are studied. Investigation of magnetization ( $M$ ) is also performed and this analysis reveals an interplay of diamagnetic and paramagnetic nature of the system in the presence of a magnetic field of varying strength. Further, to understand the system dynamics under equilibrium and non-equilibrium conditions, the effect of the non-extensive parameter ( $q$ ) on the above observables is also studied.
↳ hep-phnucl-thJ.Phys.G(2023)·14 citations
08
Rise and fall of $Λ$ and $Λ ˉ$ global polarization in semi-central heavy-ion collisions at HADES, NICA and RHIC energies from the core-corona model
Alejandro Ayala🇲🇽 · Isabel Domínguez🇲🇽 · Ivonne Maldonado🇲🇽 · María Elena Tejeda-Yeomans🇲🇽
We compute the $Λ$ and $Λ$ global polarizations in semi-central heavy-ion collisions using the core-corona model where the source of $Λ$ 's and $Λ$ 's is taken as consisting of a high-density core and a less dense corona. We show that the overall properties of the polarization excitation functions can be linked to the relative abundance of $Λ$ s coming from the core versus those coming from the corona. For low collision energies, the former are more abundant whereas for higher energies the latter become more abundant. The main consequence of this reversing of the relative abundance is that both polarizations peak at collision energies $s_{N N} ≲ 10$ GeV. The exact positions and heights of these peaks depend not only on this reversal of relative abundances, but also on the centrality class, which is directly related to the QGP volume and lifetime, as well as on the relative abundances of $Λ$ s and $Λ$ s in the core and corona regions.The intrinsic polarizations are computed from a field theoretical approach that links the alignment of the strange quark spin with the thermal vorticity and modeling the QGP volume and lifetime using a Bjorken expansion scenario. We predict that the $Λ$ and $Λ$ global polarizations should peak at the energy range accessible to NICA and HADES.
↳ hep-phnucl-exnucl-thPRC(2022)·29 citations
09
Twin stars: probe of phase transition from hadronic to quark matter
T. Deloudis🇬🇷 · P.S. Koliogiannis🇬🇷 · Ch.C. Moustakidis🇬🇷
In agreement with the gravitational-wave events which are constantly increasing, new aspects of the internal structure of compact stars have come to light. A scenario in which a first order transition takes place inside these stars is of particular interest as it can lead, under conditions, to a third gravitationally stable branch (besides white dwarfs and neutron stars). This is known as the twin star scenario. The new branch yields stars with the same mass as normal compact stars but quite different radii. In the current work, we focus on hybrid stars undergone a hadron to quark phase transition near their core and how this new stable configuration arises. Emphasis is to be given especially in the aspects of the phase transition and its parameterization in two different ways, namely with Maxwell construction and with Gibbs construction. Qualitative findings of mass-radius relations of these stars will also be presented.
↳ astro-ph.HEnucl-thEPJ Web Conf.(2021)·9 citations
10
String breaking in a cold wind as seen by string models
Oleg Andreev🇷🇺
Using the gauge/string duality, we model a heavy quark-antiquark pair in a color singlet state moving through a cold medium and explore the consequences of temperature and velocity on string breaking. We show that the string breaking distance slowly varies with temperature and velocity away from the critical line but could fall near it.
↳ hep-phhep-lathep-thnucl-thNPB(2022)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

Toward precision jet event shape for future Electron-Ion Collider

Monte Carlo simulations of the S-shaped neutron guides with asymmetric concave and convex surface coatings

"Smashing more than two": Deuteron production in relativistic heavy ion collisions via stochastic multi-particle reactions

Hadron gas in the presence of a magnetic field using non-extensive statistics: A transition from diamagnetic to paramagnetic system

Rise and fall of Λ and Λˉ global polarization in semi-central heavy-ion collisions at HADES, NICA and RHIC energies from the core-corona model

Twin stars: probe of phase transition from hadronic to quark matter

String breaking in a cold wind as seen by string models

Affiliations

Rise and fall of $Λ$ and $Λ ˉ$ global polarization in semi-central heavy-ion collisions at HADES, NICA and RHIC energies from the core-corona model