Nuclear Theory·nucl-th

Friday·April 21, 2023

15 papers—5 primary·10 cross-listed

06
Neutron Stars in Modified Teleparallel Gravity
S. G. Vilhena🇧🇷 · S. B. Duarte🇧🇷 · M. Dutra🇧🇷 · P. J. Pompeia🇧🇷
We investigate compact objects in modified teleparallel gravity with realistic equations of state. We propose a modification of Teleparallel Equivalent to General Relativity, then an appropriate tetrad is applied to the field equations. A specific set of relations showing an equivalency between our gravitational model and the New General Relativity is found. The conservation equation implies that our Tolman-Oppenheimer-Volkoff equations are presented with an effective gravitational coupling constant. Numerical analysis using realistic equations of state is made, and the behavior of mass, radius, and the relation mass-radius as functions of a free parameter of our model is also investigated.
↳ gr-qcastro-ph.HEnucl-thJCAP(2023)·13 citations
07
Dark matter effects in modified teleparallel gravity
S. G. Vilhena🇧🇷 · M. Dutra🇧🇷 · O. Lourenço🇧🇷 · P. J. Pompeia🇧🇷
This work investigates dark matter (DM) effects in compact objects in modified teleparallel gravity (MTG) in which a modification of Teleparallel Equivalent to General Relativity is used. We applied a tetrad to the modified field equations where a set of relations is found. The conservation equation allows us to rewrite our Tolman-Oppenheimer-Volkoff equations with an effective gravitational coupling constant. As input to these new equations, we use a relativistic mean-field (RMF) model with dark matter content included, obtained from a Lagrangian density with both, hadronic and dark particle degrees of freedom, as well as the Higgs boson, used as a mediator in both sectors of the theory. Through numerical calculations, we analyze the mass-radius diagrams obtained from different parametrizations of the RMF-DM model, generated by assuming different values of the dark particle Fermi momentum and running the free parameter coming from the MTG. Our results show that it is possible for the system simultaneously support more DM content, and be compatible with recent astrophysical data provided by LIGO and Virgo Collaboration, as well as by NASA's Neutron star Interior Composition Explorer (NICER).
↳ gr-qcastro-ph.HEnucl-thPRD(2023)·4 citations
08
Soft gluon self-energy at finite temperature and density: hard NLO corrections in general covariant gauge
Tyler Gorda🇩🇪 · Risto Paatelainen🇫🇮 · Saga Säppi🇩🇪 · Kaapo Seppänen🇫🇮
We compute the next-to-leading order (NLO) hard correction to the gluon self-energy tensor with arbitrary soft momenta in a hot and/or dense weakly coupled plasma in Quantum Chromodynamics. Our diagrammatic computations of the two-loop and power corrections are performed within the hard-thermal-loop (HTL) framework and in general covariant gauge, using the real-time formalism. We find that after renormalization our individual results are finite and gauge-dependent, and they reproduce previously computed results in Quantum Electrodynamics in the appropriate limit. Combining our results, we also recover a formerly known gauge-independent matching coefficient and associated screening mass in a specific kinematic limit. Our NLO results supersede leading-order HTL results from the 1980s and pave the way to an improved understanding of the bulk properties of deconfined matter, such as the equation of state.
↳ hep-phnucl-thJHEP(2023)·16 citations
09
Coulomb Corrections for Coherent Neutrino Nucleus Scattering
Ryan Plestid🇺🇸
In this work we consider sub-leading $O (Z^{2} α^{3})$ corrections to coherent elastic neutrino nucleus scattering (CEvNS). These corrections are not negligible by power counting since nuclei with large coherent cross sections have sizeable nuclear charges e.g.\ $Z α \sim 0.4$ . We find that the corrections are much smaller than naive power counting in $Z α$ would suggest and that Coulomb corrections do not substantially alter predictions for CEvNS in the Standard Model. We comment on similarities to older literature on mesonic and muonic atoms.
↳ hep-phhep-exnucl-exnucl-th+1JHEP(2025)·1 citation
10
Propagation of gauge fields in hot and dense plasmas at higher orders
Andreas Ekstedt🇩🇪
Thermal field theory is indispensable for describing hot and dense systems. Yet perturbative calculations are often stymied by a host of energy scales, and tend to converge slowly. This means that precise results require the apt use of effective field theories. In this paper we refine the effective description of slowly varying gauge field known as hard thermal loops. We match this effective theory to the full theory to two-loops. Our results apply for any renormalizable model and fermion chemical potential. We also discuss how to consistently define asymptotic masses at higher orders; and how to treat spectral functions close to the lightcone. In particular, we demonstrate that the gluon mass is well-defined to next-to-leading order.
↳ hep-phnucl-th11 citations
11
Khuri-Treiman analysis of $J / ψ \to π^{+} π^{-} π^{0}$
JPAC Collaboration: M. Albaladejo🇪🇸 · S. Gonzàlez-Solís🇺🇸 · Ł. Bibrzycki🇵🇱 · C. Fernández-Ramírez🇪🇸 · N. Hammoud🇵🇱 · V. Mathieu🇪🇸 · M. Mikhasenko🇩🇪 · G. Montaña🇺🇸 · R. J. Perry🇪🇸 · A. Pilloni🇮🇹 · A. Rodas🇺🇸 · W. A. Smith🇺🇸 · A. Szczepaniak🇺🇸 · D. Winney🇨🇳
We study the decay $J / ψ \to π^{+} π^{-} π^{0}$ within the framework of the Khuri-Treiman equations. We find that the BESIII experimental di-pion mass distribution in the $ρ (770)$ -region is well reproduced with a once-subtracted $P$ -wave amplitude. Furthermore, we show that $F$ -wave contributions to the amplitude improve the description of the data in the $π π$ mass region around 1.5 GeV. We also present predictions for the $J / ψ \to π^{0} γ^{*}$ transition form factor.
↳ hep-phhep-exnucl-thPRD(2023)·12 citations
12
Transvese momentum dependent parton distributions of pion at leading twist
Wei Kou🇨🇳 · Chao Shi🇨🇳 · Xurong Chen🇨🇳 · Wenbao Jia🇨🇳
We calculate the leading twist pion unpolarized transverse momentum distribution $f_{1} (x, k_{T}^{2})$ and the Boer-Mulders function $h_{1}^{⊥} (x, k_{T}^{2})$ , using leading Fock-state light front wave functions (LF-LFWFs) based on Dyson-Schwinger and Bethe-Salpeter equations. These DS-BSEs based LF-LFWFs provide dynamically generated s- and p-wave components, which are indispensable in producing chirally odd Boer-Mulders function that has one parton spin flipped. Employing a non-perturbative SU(3) gluon rescattering kernel to treat the gauge link of the Boer-Mulders function, we thus obtain both TMDs at hadronic scale and then evolve them to the scale of $μ^{2} = 4.0$ GeV $^{2}$ . We finally calculate the generalized Boer-Mulders shift and find it to be in agreement with the lattice prediction.
↳ hep-phnucl-thPRD(2023)·14 citations
13
Energy loss of heavy quarks in the presence of magnetic field
Mohammad Yousuf Jamal🇮🇳 · Jai Prakash🇮🇳 · Indrani Nilima🇮🇳 · Aritra Bandyopadhyay🇩🇪
We study the heavy quark energy loss in the presence of a background magnetic field. The analysis considers the high magnetic field generated by spectators from initial hard collisions that were incorporated using the medium-modified Debye mass, determined from quark condensates at finite temperature and magnetic field via recent lattice quantum chromodynamics (LQCD) calculations. We analyse the impact of medium polarization on the heavy quark propagation in a quark-gluon plasma formed in relativistic heavy-ion colliders like RHIC and LHC. For simplification, we considered the static medium with constant temperature and magnetic field values. Then, we explore the nuclear modification factor ( $R_{AA}$ ) at different magnitudes of magnetic field strengths at fixed temperatures. The energy loss of heavy quarks significantly increases, leading to $R_{AA}$ suppression at higher magnetic field values
↳ hep-phnucl-thJ.Phys.G(2024)·17 citations
14
$Δ$ baryon spectroscopy in lattice QCD
Liam Hockley🇦🇺 · Waseem Kamleh🇦🇺 · Derek Leinweber🇦🇺 · Anthony Thomas🇦🇺
A variational analysis is performed within the framework of lattice QCD to extract the masses of the spin-3/2 positive parity $Δ^{+}$ baryons, including radial excitations. $2 + 1$ flavour dynamical gauge-field configurations provided by the PACS-CS collaboration via the ILDG are considered. To improve our interpolator basis, we perform an iterative process of source and sink smearing and solve a generalised eigenvalue problem using the resulting fermion operators. We obtain a clear signal for the ground and first excited states at a light quark mass corresponding to $m_{π} = 413$ MeV. Furthermore, we show that one can use the eigenvectors obtained in this method to investigate the nature of these states, allowing us to classify our results as $1 s$ and $2 s$ states for the ground and first excited states respectively. Finally, we briefly highlight the method of Hamiltonian Effective Field Theory which can be used to make comparison with quark model expectations.
↳ hep-latnucl-thFew Body Syst.(2023)·3 citations
15
Exploring the axion potential and axion walls in dense quark matter
Bonan Zhang🇨🇳 · David E. A. Castillo🇵🇱 · Ana G. Grunfeld🇦🇷 · Marco Ruggieri🇮🇹
We study the potential of the Quantum Chromodynamics axion in hot and/or dense quark matter, within a Nambu-Jona-Lasinio-like model that includes the coupling of the axion to quarks. Differently from previous studies, we implement local electrical neutrality and $β -$ equilibrium, which are relevant for the description of the quark matter in the core of compact stellar objects. Firstly we compute the effects of the chiral crossover on the axion mass and self-coupling. We find that the low energy properties of axion are very sensitive to the phase transition of Quantum Chromodynamics, in particular, when the bulk quark matter is close to criticality. Then, for the first time in the literature we compute the axion potential at finite quark chemical potential and study the axion domain walls in bulk quark matter. We find that the energy barrier between two adjacent vacuum states decrease in the chirally restored phase: this results in a lower surface tension of the walls. Finally, we comment on the possibility of production of walls in dense quark matter.
↳ hep-phnucl-thPRD(2023)·14 citations

Affiliations

first authorsco-authorsvia INSPIRE