Nuclear Theory·nucl-th

Monday·September 27, 2021

10 papers—4 primary·6 cross-listed

01
[Submitted on 24 Sept 2021]
Exploring the $Σ^{+} p$ interaction by measurements of the correlation function
J. Haidenbauer🇩🇪 · U.-G. Meißner🇩🇪
The spin-dependent components of the fundamental hyperon-nucleon interactions are largely unknown. We show that under reasonable assumptions, a measurement of the $Σ^{+} p$ correlation function in high-energy proton-proton or heavy-ion collisions combined with cross section data allows to separate the singlet and the triplet $S$ -wave contributions.
Comments:
6 pages, 3 figures, discussion extended, references updated
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2109.11794 [pdf]
PLB(2022)·20 citations
02
[Submitted on 24 Sept 2021]
Properties of neutron star crust with improved nuclear physics: Impact of chiral EFT interactions and experimental nuclear masses
Grams · G. · Margueron · J. · Somasundaram · R. · Reddy · S
A compressible liquid-drop approach adjusted to uniform matter many-body calculations based on chiral EFT interactions and to the experimental nuclear masses is used to investigate the neutron star crust properties. Eight chiral EFT hamiltonians and a representative phenomenological force (SLy4) are confronted. We show that some properties of the crust, e.g. clusters mass, charge, and asymmetry, are mostly determined by symmetric matter properties close to saturation density and are therefore mainly constrained by experimental nuclear masses, while other properties, e.g., energy per particle, pressure, sound speed, are mostly influenced by low-density predictions in neutron matter, where chiral EFT and phenomenological forces substantially differ.
Comments:
11 pages, 7 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
2109.11857 [pdf]
Few Body Syst.(2021)·14 citations
03
[Submitted on 24 Sept 2021]
Constraining nuclear matter parameters and neutron star observables using PREX-2 and NICER data
S. K. Biswal · H. C. Das · Ankit Kumar · S. K. Patra
We try to constraints some of the nuclear matter parameters such as symmetry energy ( $J$ ) and its slope ( $L$ ) from the recent inferred data of the PREX-2. Other nuclear matter parameters are adopted from {\bf [Phys. Rev. C 85 035201 (2012), Phys. Rev. C 90 055203 (2014)]} papers and the linear correlation among them are checked by using the Pearson's formula. We find the correlation between $J - L$ , $K_{τ} - J$ and $K_{τ} - L$ with coefficients 0.85, 0.81 and 0.76 respectively. The neutron star properties such as mass and radius are calculated with 50 unified equation of states. The results are consistent with recently observed pulsars and NICER data except few exceptions. From the radii constraints, we find that the new NICER data allows a narrow radius range contrary to a large range of PREX-2 and the old NICER data leaving us an inconclusive determination of the neutron star radius.
Comments:
5 pages, 4 figures, comments welcome
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
2109.11895 [pdf]
2 citations
04
[Submitted on 24 Sept 2021]
Pseudogauge dependence of the spin polarization and of the axial vortical effect
M. Buzzegoli🇺🇸
The mean spin polarization vector of spin 1/2 particles in a relativistic fluid at local thermal equilibrium (LTE) in different pseudogauges (PGs), i.e., with different choices for the decomposition of orbital and spin angular momentum, is obtained. The spin polarization obtained in the canonical PG differs from the one obtained in the Belinfante PG. It is found that this difference can not be written by replacing the thermal vorticity with the spin potential in the usual polarization formula. Other PG choices affect the contribution of thermal shear to the spin polarization. Therefore, the choice of a PG affects the predictions for the polarization measured in heavy-ion collisions. In general, it is shown that the Wigner function of a noninteracting Dirac field at LTE is affected by the PG transformations. Explicit expressions of the mean axial current are also calculated and it is found that even the axial vortical effect conductivity depends on the PG.
Comments:
14 pages, Final proofread version published in PRC
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2109.12084 [pdf]
PRC(2022)·51 citations
05
[Submitted on 23 Sept 2021] (cross-list from hep-ph)
Probing a dilute short lived Quark Gluon Plasma medium with jets
Varun Vaidya🇺🇸
I look at propagation of jets that act as a probe of the medium in the phenomenologically relevant case of a short lived dilute Quark Gluon Plasma(QGP) created during heavy ion collisions. Working in the regime where the lifetime of the medium is of the order or smaller than the formation time of the energetic jet, I derive a factorization formula with a manifest separation of scales for an illustrative jet substructure observable using the Open Quantum system Effective Field Theory(EFT) approach developed in \cite{Vaidya:2020lih}, in terms of a medium structure function and a medium induced jet function . The medium structure function or the "PDF of the medium" that describes the observable independent physics of the QGP remains identical to that in a dilute long lived medium considered in \cite{Vaidya:2021vxu}, while the medium induced jet function is modified and incorporates quantum interference between the hard interaction that creates the jet and subsequent medium interactions. The medium jet function continues to enjoy a BFKL rapidity evolution just as for a long lived medium, albeit with a modified renormalization scale that now depends on the medium lifetime.
Comments:
30 pages +Appendix
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2109.11568 [pdf]
9 citations
06
[Submitted on 23 Sept 2021] (cross-list from hep-ph)
Revealing pion and kaon structure via generalised parton distributions
Khepani Raya🇨🇳 · Zhu-Fang Cui🇨🇳 · Lei Chang🇨🇳 · Jose-Manuel Morgado🇪🇸 · Craig D. Roberts🇨🇳 · Jose Rodriguez-Quintero🇪🇸
Clear windows onto emergent hadron mass (EHM) and modulations thereof by Higgs boson interactions are provided by observable measures of pion and kaon structure, many of which are accessible via generalised parton distributions (GPDs). Beginning with algebraic GPD Ansaetze, constrained entirely by hadron-scale $π$ and $K$ valence-parton distribution functions (DFs), in whose forms both EHM and Higgs boson influences are manifest, numerous illustrations are provided. They include the properties of electromagnetic form factors, impact parameter space GPDs, gravitational form factors and associated pressure profiles, and the character and consequences of all-orders evolution. The analyses predict that mass-squared gravitational form factors are stiffer than electromagnetic form factors; reveal that $K$ pressure profiles are tighter than $π$ profiles, with both mesons sustaining near-core pressures at magnitudes similar to that expected at the core of neutron stars; deliver parameter-free predictions for $π$ and $K$ valence, glue, and sea GPDs at the resolving scale $ζ = 2$ GeV; and predict that at this scale the fraction of meson mass-squared carried by glue and sea combined matches that lodged with the valence degrees-of-freedom, with a similar statement holding for mass-squared radii.
Comments:
22 pages, 19 figures, 2 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2109.11686 [pdf]
CPC(2022)·83 citations
07
[Submitted on 24 Sept 2021] (cross-list from hep-ph)
Energy-momentum tensor in QCD: nucleon mass decomposition and mechanical equilibrium
Cédric Lorcé🇫🇷 · Andreas Metz🇺🇸 · Barbara Pasquini🇮🇹 · Simone Rodini🇮🇹
We review and examine in detail recent developments regarding the question of the nucleon mass decomposition. We discuss in particular the virial theorem in quantum field theory and its implications for the nucleon mass decomposition and mechanical equilibrium. We reconsider the renormalization of the QCD energy-momentum tensor in minimal-subtraction-type schemes and the physical interpretation of its components, as well as the role played by the trace anomaly and Poincaré symmetry. We also study the concept of "quantum anomalous energy" proposed in some works as a new contribution to the nucleon mass. Examining the various arguments, we conclude that the quantum anomalous energy is not a genuine contribution to the mass sum rule, as a consequence of translation symmetry.
Comments:
31 pages
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2109.11785 [pdf]
JHEP(2021)·89 citations
08
[Submitted on 24 Sept 2021] (cross-list from hep-ph)
A theory vade mecum for PSI experiments
Gilberto Colangelo🇨🇭 · Franziska Hagelstein🇨🇭 · Adrian Signer🇨🇭 · Peter Stoffer🇦🇹
This article gives a compact introduction and overview of the theory underlying the experiments described in the rest of this review.
Comments:
This is Chapter 5 of the Review of Particle Physics at PSI, published in SciPost Proceedings 5
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2109.11948 [pdf]
SciPost Phys.Proc.(2021)·4 citations
09
[Submitted on 24 Sept 2021] (cross-list from hep-ph)
An alternative scheme for effective range corrections in pionless EFT
M. Ebert🇩🇪 · H.-W. Hammer🇩🇪 · A. Rusetsky🇩🇪
We discuss an alternative scheme for including effective range corrections in pionless effective field theory. The standard approach treats range terms as perturbative insertions in the T -matrix. In a finite volume this scheme can lead to singular behavior close to the unperturbed energies. We consider an alternative scheme that resums the effective range but expands the spurious pole of the T -matrix created by this resummation. We test this alternative expansion for several model potentials and observe good convergence.
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2109.11982 [pdf]
EPJA(2021)·16 citations
10
[Submitted on 24 Sept 2021] (cross-list from hep-ph)
Anomalous diffusion in QCD matter
Paul Caucal🇺🇸 · Yacine Mehtar-Tani🇺🇸
We study the effects of quantum corrections on transverse momentum broadening of a fast parton passing through dense QCD matter. We show that, at leading logarithmic accuracy the broadening distribution tends at late times or equivalently for large system sizes $L$ to a universal distribution that only depends on a single scaling variable $k_{⊥}^{2} / Q_{s}^{2}$ where the typical transverse momentum scale increases with time as $ln Q_{s}^{2} ≃ (1 + 2 β) ln L - \frac{3}{2} (1 + β) ln ln L$ up to non-universal terms, with an anomalous dimension $β \sim α_{s}$ . This property is analogous to geometric scaling of gluon distributions in the saturation regime and traveling waves solutions to reaction-diffusion processes. We note that since $β > 0$ the process is super-diffusive, which is also reflected at large transverse momentum where the scaling distribution exhibits a heavy tail $k_{⊥}^{4 - 2 β}$ akin to Lévy random walks.
Comments:
10 pages, 3 figures, 3 supplemental materials
Subjects:
High Energy Physics — Phenomenology (hep-ph); Statistical Mechanics (cond-mat.stat-mech); Nuclear Theory (nucl-th)
arXiv:
2109.12041 [pdf]
PRD(2022)·29 citations

Affiliations

first authorsco-authorsvia INSPIRE