Nuclear Theory·nucl-th

Monday·June 1, 2020

17 papers—7 primary·10 cross-listed

08
[Submitted on 28 May 2020] (cross-list from hep-th)
Transport in strongly coupled quark matter
Carlos Hoyos🇪🇸 · Niko Jokela🇫🇮 · Matti Jarvinen🇮🇱 · Javier G. Subils🇪🇸 · Javier Tarrio🇫🇮 · Aleksi Vuorinen🇫🇮
Motivated by the possible presence of deconfined quark matter in neutron stars and their mergers and the important role of transport phenomena in these systems, we perform the first-ever systematic study of different viscosities and conductivities of dense quark matter using the gauge/gravity duality. Utilizing the V-QCD model, we arrive at results that are in qualitative disagreement with the predictions of perturbation theory, which highlights the differing transport properties of the system at weak and strong coupling and calls for caution in the use of the perturbative results in neutron-star applications.
Comments:
10 pages, 4 figures; v2: revised version, accepted in PRL
Subjects:
High Energy Physics — Theory (hep-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2005.14205 [pdf]
PRL(2020)·42 citations
09
[Submitted on 28 May 2020] (cross-list from astro-ph.HE)
The landscape of disk outflows from black hole - neutron star mergers
Rodrigo Fernández · Francois Foucart · Jonas Lippuner
We investigate mass ejection from accretion disks formed in mergers of black holes (BHs) and neutron stars (NSs). The third observing run of the LIGO/Virgo interferometers provided BH-NS candidate events that yielded no electromagnetic (EM) counterparts. The broad range of disk configurations expected from BH-NS mergers motivates a thorough exploration of parameter space to improve EM signal predictions. Here we conduct 27 high-resolution, axisymmetric, long-term hydrodynamic simulations of the viscous evolution of BH accretion disks that include neutrino emission/absorption effects and post-processing with a nuclear reaction network. In the absence of magnetic fields, these simulations provide a lower-limit to the fraction of the initial disk mass ejected. We find a nearly linear inverse dependence of this fraction on disk compactness (BH mass over initial disk radius). The dependence is related to the fraction of the disk mass accreted before the outflow is launched, which depends on the disk position relative to the innermost stable circular orbit. We also characterize a trend of decreasing ejected fraction and decreasing lanthanide/actinide content with increasing disk mass at fixed BH mass. This trend results from a longer time to reach weak freezout and an increasingly dominant role of neutrino absorption at higher disk masses. We estimate the radioactive luminosity from the disk outflow alone available to power kilonovae over the range of configurations studied, finding a spread of two orders of magnitude. For most of the BH-NS parameter space, the disk outflow contribution is well below the kilonova mass upper limits for GW190814.
Comments:
Accepted by MNRAS with minor revisions
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
2005.14208 [pdf]
MNRAS(2020)·74 citations
10
[Submitted on 28 May 2020] (cross-list from hep-ph)
The Drell-Yan process with pions and polarized nucleons
S. Bastami🇺🇸 · L. Gamberg🇺🇸 · B. Parsamyan🇮🇹 · B. Pasquini🇮🇹 · A. Prokudin🇺🇸 · P. Schweitzer🇺🇸
The Drell-Yan process provides important information on the internal structure of hadrons including transverse momentum dependent parton distribution functions (TMDs). In this work we present calculations for all leading twist structure functions describing the pion induced Drell-Yan process. The non-perturbative input for the TMDs is taken from the light-front constituent quark model, the spectator model, and available parametrizations of TMDs extracted from the experimental data. TMD evolution is implemented at Next-to-Leading Logarithmic precision for the first time for all asymmetries. Our results are compatible with the first experimental information, help to interpret the data from ongoing experiments, and will allow one to quantitatively assess the models in future when more precise data will become available.
Comments:
The paper is restructured with new discussions and results, TMD evolution is implemented at Next-to-Leading Logarithmic accuracy for all asymmetries. 27 pages and 10 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2005.14322 [pdf]
JHEP(2021)·25 citations
11
[Submitted on 29 May 2020] (cross-list from hep-ph)
Unitarization Technics in Hadron Physics with Historical Remarks
J. A. Oller🇪🇸
We review a series of unitarization techniques that have been used during the last decades, many of them in connection with the advent and development of current algebra and later of Chiral Perturbation Theory. Several methods are discussed like the generalized effective-range expansion, K-matrix approach, Inverse Amplitude Method, Padé approximants and the N/D method. More details are given for the latter though. We also consider how to implement them in order to correct by final-state interactions. In connection with this some other methods are also introduced like the expansion of the inverse of the form factor, the Omnés solution, generalization to coupled channels and the Khuri-Treiman formalism, among others.
Comments:
45 pages, 2 figures. Invited contribution to a special issue on "Effective Field Theories - Chiral Perturbation Theory and Non-relativistic QFT". Updated to match the published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2005.14417 [pdf]
Symmetry(2020)·51 citations
12
[Submitted on 29 May 2020] (cross-list from hep-ph)
Impact of off-shell dynamics on the transport properties and the dynamical evolution of Charm Quarks at RHIC and LHC temperatures
Maria Lucia Sambataro (1 and 2)🇮🇹 · Salvatore Plumari (1 and 2)🇮🇹 · Vincenzo Greco (1 and 2) ((1) Department of Physics and Astronomy 'E. Majorana', University of Catania, (2) Laboratori Nazionali del Sud, INFN-LNS)🇮🇹
We evaluate drag and diffusion transport coefficients comparing a quasi-particle approximation with on-shell constituents of the QGP medium and a dynamical quasi-particles model with off-shell bulk medium at finite temperature T. We study the effects of the width $γ$ of the particles of the bulk medium on the charm quark transport properties exploring the range where $γ < M_{q, g}$ . We find that off-shell effects are in general quite moderate and can induce a reduction of the drag coefficient at low momenta that disappear already at moderate momenta, $p ≳ 2 - 3 GeV$ . We also observe a moderate reduction of the breaking of the Fluctuation-Dissipation theorem (FDT) at finite momenta. Moreover, we have performed a first study of the dynamical evolution of HQ elastic energy loss in a bulk medium at fixed temperature extending the Boltzmann (BM) collision integral to include off-shell dynamics. A comparison among the Langevin dynamics, the BM collisional integral with on-shell and the BM extension to off-shell dynamics shows that the evolution of charm energy when off-shell effects are included remain quite similar to the case of the on-shell BM collision integral.
Comments:
13 pages, 14 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2005.14470 [pdf]
EPJC(2020)·22 citations
13
[Submitted on 29 May 2020] (cross-list from nucl-ex)
Re-evaluation of the $^{22}$ Ne( $α, γ$ ) $^{26}$ Mg and $^{22}$ Ne( $α, n$ ) $^{25}$ Mg reaction rates
Philip Adsley🇫🇷 · Umberto Battino🇬🇧 · Andreas Best🇮🇹 · Antonio Caciolli🇮🇹 · Alessandra Guglielmetti🇮🇹 · Gianluca Imbriani🇮🇹 · Heshani Jayatissa🇺🇸 · Marco La Cognata🇮🇹 · Livio Lamia🇮🇹 · Eliana Masha🇮🇹 · Cristian Massimi🇮🇹 · Sara Palmerini🇮🇹 · Ashley Tattersall🇬🇧 · Raphael Hirschi🇬🇧
The competing $^{22}$ Ne( $α, γ$ ) $^{26}$ Mg and $^{22}$ Ne( $α, n$ ) $^{25}$ Mg reactions control the production of neutrons for the weak $s$ -process in massive and AGB stars. In both systems, the ratio between the corresponding reaction rates strongly impacts the total neutron budget and strongly influences the final nucleosynthesis. The $^{22}$ Ne( $α, γ$ ) $^{26}$ Mg and $^{22}$ Ne( $α, n$ ) $^{25}$ Mg reaction rates was re-evaluated by using newly available information on $^{26}$ Mg given by various recent experimental studies. Evaluations of The evaluated $^{22}$ Ne( $α, γ$ ) $^{26}$ Mg reaction rate remains substantially similar to that of Longland {\it et al.} but, including recent results from Texas A\&M, the $^{22}$ Ne( $α, n$ ) $^{25}$ Mg reaction rate is lower at a range of astrophysically important temperatures. Stellar models computed with NEWTON and MESA predict decreased production of the weak branch $s$ -process due to the decreased efficiency of $^{22}$ Ne as a neutron source. Using the new reaction rates in the MESA model results in $^{96}$ Zr/ $^{94}$ Zr and $^{135}$ Ba/ $^{136}$ Ba ratios in much better agreement with the measured ratios from presolar SiC grains.
Comments:
23 pages, 15 figures, updated
Subjects:
Nuclear Experiment (nucl-ex); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
arXiv:
2005.14482 [pdf]
PRC(2021)·48 citations
14
[Submitted on 29 May 2020] (cross-list from nucl-ex)
Energy dependence of the optical potential of the weakly bound 9Be projectile on the 197Au target
F. Gollana🇦🇷 · D. Abriola🇦🇷 · A. Arazia🇦🇷 · M. A. Cardonaa🇦🇷 · E. de Barbara🇦🇷 · D. Hojmana🇦🇷 · R.M. Id Betan🇦🇷 · G.V. Marti🇦🇷 · A.J. Pacheco🇦🇷 · D. Rodriguesa🇦🇷 · M. Togneri🇦🇷
In this work we measured elastic and inelastic angular distributions of the weakly bound 9Be projectile on the 197Au target at several bombarding energies from 84% up to 140% of the Coulomb barrier. The elastic angular distributions were analyzed using a phenomenological Woods-Saxon potential and a double folding Sao Paulo potential and the energy dependence was extracted. Angular distributions from two inelastic peaks were compared with coupled channel calculations using reduced transition probabilities available in the literature. The energy dependence of the two interaction potential models show a similar trend in the region of the Coulomb barrier. Dispersion relation calculation demonstrates the presence of the breakup threshold anomaly proposed for weakly bound systems.
Comments:
12 pages, 6 figures, 55 references
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2005.14587 [pdf]
NPA(2020)·17 citations
15
[Submitted on 29 May 2020] (cross-list from hep-ph)
Helicity-dependent extension of the McLerran-Venugopalan model
Florian Cougoulic🇺🇸 · Yuri V. Kovchegov🇺🇸
We construct a generalization of the McLerran-Venugopalan (MV) model including helicity effects for a longitudinally polarized target (a proton or a large nucleus). The extended MV model can serve as the initial condition for the helicity generalization of the JIMWLK evolution equation constructed in our previous paper, as well as for calculation of helicity-dependent observables in the quasi-classical approximation to QCD.
Comments:
24 pages, 3 figures. v2 Typos and comments
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2005.14688 [pdf]
NPA(2020)·55 citations
16
[Submitted on 29 May 2020] (cross-list from astro-ph.HE)
Sensitivity of $^{44}$ Ti and $^{56}$ Ni production in CCSN shock-driven nucleosynthesis to reaction rates
Shiv K. Subedi · Zach Meisel · Grant Merz
Recent observational advances have enabled high resolution mapping of $^{44}$ Ti in core-collapse supernova (CCSN) remnants. Comparisons between observations and models provide stringent constraints on the CCSN mechanism. However, past work has identified several uncertain nuclear reaction rates that influence $^{44}$ Ti and $^{56}$ Ni production in post-processing model calculations. We evolved one dimensional models of $15 M_{⊙}$ , $18 M_{⊙}$ , $22 M_{⊙}$ and $25 M_{⊙}$ stars from zero-age main sequence through CCSN using {\tt MESA} (Modules for Experiments in Stellar Astrophysics) and investigated the previously identified reaction rate sensitivities of $^{44}$ Ti and $^{56}$ Ni production. We tested the robustness of our results by making various assumptions about the CCSN explosion energy and mass-cut. We found a number of reactions that have a significant impact on the nucleosynthesis of $^{44}$ Ti and $^{56}$ Ni, particularly for lower progenitor masses. Notably, the reaction rates $^{13} N (α, p)^{16} O$ , $^{17} F (α, p)^{20} Ne$ , $^{52} Fe (α, p)^{55} Co$ , $^{56} Ni (α, p)^{59} Cu$ , $^{57} Ni (n, p)^{57} Co$ , $^{56} Co (p, n)^{56} Ni$ , $^{39} K (p, γ)^{40} Ca$ , $^{47} V (p, γ)^{48} Cr$ , $^{52} Mn (p, γ)^{53} Fe$ , $^{57} Co (p, γ)^{58} Ni$ , and $^{39} K (p, α)^{36} Ar$ are influential for a large number of model conditions. Furthermore, we found the list of influential reactions identified by previous post-processing studies of CCSN shock-driven nucleosynthesis is likely incomplete, motivating future larger-scale sensitivity studies.
Comments:
15 pages, 7 figures, 3 tables; Accepted to the Astrophysical Journal
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2005.14702 [pdf]
ApJ(2020)·14 citations
17
[Submitted on 29 May 2020] (cross-list from nucl-ex)
Probing short-range correlations in the deuteron via incoherent diffractive $J / ψ$ production with spectator tagging at the EIC
Zhoudunming Tu🇺🇸 · Alexander Jentsch🇺🇸 · Mark Baker · Liang Zheng🇨🇳 · Jeong-Hun Lee🇺🇸 · Raju Venugopalan🇺🇸 · Or Hen🇺🇸 · Douglas Higinbotham🇺🇸 · Elke-Caroline Aschenauer🇺🇸 · Thomas Ullrich🇺🇸
Understanding the role of Quantum Chromodynamics in generating nuclear forces is important for uncovering the mechanism of short-ranged nuclear interactions and their manifestation in short range correlations (SRC). The future Electron-Ion-Collider (EIC) at Brookhaven National Laboratory in the US will provide an unprecedented opportunity to systematically investigate the underlying physics of SRC for energies and kinematic regions that are otherwise impossible to reach. We study SRCs in electron-deuteron scattering events using the Monte Carlo event generator BeAGLE. Specifically, we investigate the sensitivity of observables to high internal nucleon momentum in incoherent diffractive $J / ψ$ vector meson production. In a plane wave impulse approximation, the initial state deuteron wavefunction can be accessed directly from the four-momentum of the spectator nucleon. We use realistic physics simulations and far-forward detector simulations of the EIC to fully reveal the physics potential of this exclusive process. In particular, we provide the luminosity and detector requirements necessary to study SRCs in the deuteron at an EIC.
Comments:
There are a total of 7 figures and 2 tables in the main text, together with an Appendix with supplemental material
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2005.14706 [pdf]
PLB(2020)·40 citations

Affiliations

first authorsco-authorsvia INSPIRE