Nuclear Theory·nucl-th

Friday·December 22, 2023

17 papers—9 primary·8 cross-listed

10
On the spin period distribution of millisecond pulsars
Xiao-Jin Liu · Zhi-Qiang You · Zu-Cheng Chen · Shen-Shi Du · Ang Li · Xing-Jiang Zhu
Spin period distribution provides important clues to understand the formation of millisecond pulsars (MSPs). To uncover the intrinsic period distribution, we analyze three samples of radio MSPs in the Galactic field and in globular clusters. The selection bias due to pulse broadening has been corrected but turns out to be negligible. We find that all the samples can be well described by a Weibull distribution of spin frequencies. Considering MSPs in the Galactic field or in globular clusters, and in isolation or in binary systems, we find no significant difference in the spin distribution among these subpopulations. Based on the current known population of MSPs, we find that sub-millisecond pulsars are unlikely to be discovered by the Square Kilometer Array, although up to $\sim 10$ discoveries of pulsars that spin faster than the current record holder of $P = 1.4$ ~ms are expected.
↳ astro-ph.HEnucl-thApJ(2024)·11 citations
11
JLab spectral functions of argon in NuWro and their implications for MicroBooNE
Rwik Dharmapal Banerjee🇵🇱 · Artur M. Ankowski🇵🇱 · Krzysztof M. Graczyk🇵🇱 · Beata E. Kowal🇵🇱 · Hemant Prasad🇵🇱 · Jan T. Sobczyk🇵🇱
The Short-Baseline Neutrino program in Fermilab aims to resolve the nature of the low-energy excess events observed in LSND and MiniBooNE, and analyze with unprecedented precision neutrino interactions with argon. These studies require reliable estimate of neutrino cross sections, in particular for charged current quasielastic scattering (CCQE). Here, we report updates of the NuWro Monte Carlo generator that, most notably, bring the state-of-the-art spectral functions to model the ground state properties of the argon nucleus, and improve the accuracy of the cross sections at low energies by accounting for the effects of the nuclear Coulomb potential. We discuss these developments in the context of electron and neutrino interactions, by comparing updated NuWro predictions to experimental data from Jefferson Laboratory Hall A and MicroBooNE. The MicroBooNE CCQE data are described with the $χ^{2}$ per degree of freedom of 0.7, compared with 1.0 in the local Fermi gas model. The largest improvement is observed for the angular distributions of the produced protons, where the $χ^{2}$ reduces nearly by half. Being obtained using the axial form factor parametrization from MINERvA, our results indicate a~consistency between the CCQE measurements in MINERvA and MicroBooNE.
↳ hep-phnucl-thPRD(2024)·16 citations
12
Testing Eigenstate Thermalization Hypothesis for Non-Abelian Gauge Theories
Xiaojun Yao🇺🇸 · Lukas Ebner🇩🇪 · Berndt Müller🇺🇸 · Andreas Schäfer🇩🇪 · Clemens Seidl🇩🇪
We report on progress in full quantum understanding of thermalization in non-Abelian gauge theories. Specifically, we test the eigenstate thermalization hypothesis for (2+1)-dimensional SU(2) lattice gauge theory.
↳ hep-latcond-mat.stat-mechhep-phnucl-th+1EPJ Web Conf.(2024)·4 citations
13
Impact of the MARATHON data on \texorpdfstring{ $F_{2 n} / F_{2 p}$ }{F2n/F2p} and off-shell effects in light nuclei
T. J. Hague (1) · J. Arrington (1) · S. Li (1) · S. N. Santiesteban (2) ((1) Lawrence Berkeley National Laboratory · (2) University of New Hampshire)
The neutron structure function, $F_{2 n}$ , has historically been extracted from measurements of the deuteron structure function, but our understanding of the nuclear effects on the bound proton and neutron limits the extraction of $F_{2 n}$ . The MARATHON collaboration recently extracted $F_{2 n}$ from the comparison of $^{3}$ H and $^{3}$ He targets, where the nuclear effects are larger but nearly identical, yielding a precise extraction of $F_{2 n} / F_{2 p}$ . This precise extraction can then be compared to deuteron extractions, providing important constraints on the nuclear effects in the deuteron. To ensure that this comparison is not biased by the specific model of nuclear effects used by MARATHON, we examine a range of models of the nuclear effects to obtain a more conservative, but more model-independent, extraction of $F_{2 n} / F_{2 p}$ for comparison with deuteron extractions. Even with the more conservative approach, the comparison suggests the need for significant off-shell corrections or other nuclear effects, beyond those include in most calculations, even for the weakly-bound deuteron.
↳ nucl-exnucl-thPRC(2024)·2 citations
14
A Possible Solution to the Difficulty in the Interpretation of Deuteron Compositeness
Zanpeng Yin🇯🇵 · Daisuke Jido🇯🇵
We study the theoretical structure of compositeness with explicit energy dependence, and find a possible explanation for the difficulty in the interpretation of compositeness of deuteron. Compositeness of deuteron is calculated as larger than one in many methods like weak-binding limit. Even though it is widely assumed that the energy dependence in interaction always comes from other states, which we call surjective interpretation, we find that the outcome of deuteron may suggest a violation of surjective interpretation. We directly perform numerical and perturbative calculations of deuteron compositeness. It is concluded that if the energy dependent part of interaction contributes to attraction, compositeness is likely to be enhanced from unity. We discuss the indications of this outcome and the model dependence of compositeness. We propose a straightforward extension and a thorough revise on the formalism of compositeness with field theory considerations.
↳ hep-phnucl-thPRC(2024)·5 citations
15
Quarkonium spectral functions in a bulk-viscous quark-gluon plasma
Lata Thakur🇰🇷 · Yuji Hirono🇰🇷
We study the interplay of non-equilibrium properties of a quark-gluon plasma (QGP) and heavy quarkonia. For this purpose, we compute the quarkonium spectral functions in a bulk-viscous QGP. We take into account the bulk viscous nature of the medium by modifying the distribution functions of thermal quarks and gluons. This modification affects the dielectric permittivity, which is used to calculate the in-medium heavy quark potential. With this modified complex potential, we calculate the quarkonium spectral functions and extract their physical properties. We discuss the impact of bulk viscosity on quarkonia properties such as decay widths and binding energies. We also estimate the relative production yield of $ψ^{'}$ to $J / ψ$ and discuss the bulk viscous effects on it.
↳ hep-phnucl-thNuovo Cim.C(2024)·0 citations
16
Spectrum of the molecular pentaquarks
Bo Wang🇨🇳 · Kan Chen🇨🇳 · Lu Meng🇩🇪 · Shi-Lin Zhu🇨🇳
We investigate the mass spectrum of the molecular pentaquarks composed of a baryon and a meson. We establish the underlying relations among the near-threshold interactions of the molecular tetraquark and pentaquark systems. We find the existence of the molecule candidates in the $Σ_{c} D ˉ^{(*)}$ , $D D^{*}$ , and $D D ˉ^{*}$ systems indicates a substantial presence of the hadronic molecules in the {\it heavy} baryon plus {\it heavy} meson systems ({\it heavy} refers to the hadrons with the $c$ and/or $s$ quarks). We make an exhaustive prediction of the possible bound/virtual molecular states in the systems: $Σ_{c}^{(*)} D ˉ^{(*)}$ , $Σ_{c}^{(*)} D^{(*)}$ , $Ξ_{c}^{(', *)} D ˉ^{(*)}$ , $Ξ_{c}^{(', *)} D^{(*)}$ , $Σ_{c}^{(*)} K^{*}$ , $Σ_{c}^{(*)} K ˉ^{*}$ , $Ξ_{c}^{(', *)} K^{*}$ , $Ξ_{c}^{(', *)} K ˉ^{*}$ , $Ξ_{cc}^{(*)} D ˉ^{(*)}$ , $Ξ_{cc}^{(*)} D^{(*)}$ , $Ξ_{cc}^{(*)} K^{*}$ , $Ξ_{cc}^{(*)} K ˉ^{*}$ , $Σ^{(*)} D ˉ^{(*)}$ , $Σ^{(*)} D^{(*)}$ , $Ξ^{(*)} D ˉ^{(*)}$ , $Ξ^{(*)} D^{(*)}$ , $Σ^{(*)} K^{*}$ , $Σ^{(*)} K ˉ^{*}$ , $Ξ^{(*)} K^{*}$ , $Ξ^{(*)} K ˉ^{*}$ . Hunting for the predicted states in experiments will significantly deepen our understanding of the formation mechanism of the hadronic molecules, and shed light on the manifestation of flavor symmetry in the low-energy residual strong interactions.
↳ hep-phhep-exnucl-thPRD(2024)·31 citations
17
Nucleon to $Δ$ axial and pseudoscalar transition form factors
Chen Chen🇨🇳 · Christian S. Fischer🇩🇪 · Craig D. Roberts🇨🇳
A symmetry-preserving continuum approach to the calculation of baryon properties in relativistic quantum field theory is used to predict all form factors associated with nucleon-to- $Δ$ axial and pseudoscalar transition currents, thereby unifying them with many additional properties of these and other baryons. The new parameter-free predictions can serve as credible benchmarks for use in analysing existing and anticipated data from worldwide efforts focused on elucidation of $ν$ properties.
↳ hep-phhep-exhep-latnucl-ex+1PRL(2024)·20 citations

Affiliations

first authorsco-authorsvia INSPIRE