Nuclear Theory·nucl-th

Wednesday·April 24, 2024

8 papers—4 primary·4 cross-listed

05
[Submitted on 22 Apr 2024] (cross-list from hep-th)
Effective Field Theory for Spontaneously Broken Symmetry
Tomas Brauner🇳🇴
This is a preprint of an open-access book published by Springer Cham. The book gives an up-to-date overview of the physics of spontaneously broken continuous symmetry from the point of view of effective field theory. Upon building up the necessary foundations, the text reviews the classification of Nambu-Goldstone bosons and then focuses on the construction of the effective-field-theoretic description of their dynamics. Both internal and spacetime broken symmetries are covered, including numerous illustrative examples and a few selected applications, worked out in greater detail.
Comments:
400 pages; preprint of an open-access book published by Springer Cham. Comments are welcome, no citation requests please
Subjects:
High Energy Physics — Theory (hep-th); Quantum Gases (cond-mat.quant-gas); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2404.14518 [pdf]
Lect.Notes Phys.(2024)·21 citations
06
[Submitted on 23 Apr 2024] (cross-list from hep-ph)
Investigating $Ξ$ resonances from pentaquark perspective
Ye Yan🇨🇳 · Qi Huang🇨🇳 · Xinmei Zhu🇨🇳 · Hongxia Huang🇨🇳 · Jialun Ping🇨🇳
We have investigated the $q ss q ˉ q$ ( $q = u$ or $d$ ) system to find possible pentaquark explanations for the $Ξ$ resonances. The bound state calculation is carried out within the framework of the quark delocalization color screening model. The scattering processes are also studied to examine the possible resonance states. The current results indicate that the $Ξ (1950)$ can be interpreted as $Λ K ˉ^{*}$ state with $J^{P} = 1/ 2^{-}$ . Three states are identified that match the $Ξ (2250)$ , which are $Σ^{*} K ˉ^{*}$ state with $J^{P} = 3/ 2^{-}$ , $Σ^{*} K ˉ^{*}$ state with $J^{P} = 5/ 2^{-}$ , and $Ξ^{*} ρ$ state with $J^{P} = 5/ 2^{-}$ . This may explain the conflicting experimental values for the width of the $Ξ (2250)$ . A new $Ξ$ resonance is predicted, whose mass and width are 2066--2079 MeV and 186--189 MeV, respectively. These results contribute to understanding the nature of the $Ξ$ resonances and to the future search for new $Ξ$ resonances. Moreover, it is meaningful to further investigate the $Ξ$ resonances from an unquenched picture on the basis of pentaquark investigation.
Comments:
15 pages, 7 figures. arXiv admin note: text overlap with arXiv:2312.04977, arXiv:2309.15380
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2404.14753 [pdf]
PRD(2024)·8 citations
07
[Submitted on 23 Apr 2024] (cross-list from cond-mat.quant-gas)
Two-body problem of impurity atoms in dipolar Fermi gas
Eiji Nakano · Takahiko Miyakawa · Hiroyuki Yabu
The polarized dipolar Fermi gas shows exotic properties at low temperatures, characterized by an axially-deformed Fermi surface and anisotropic single-particle energy, due to the long-range and anisotropic nature of dipole-dipole interaction. In cold-atom experiments such a system has been realized, e.g., in degenerate gas of Er and Dy atoms. In the case that non-dipolar impurity atoms are introduced in such system, they undergoes an induced interaction mediated by the density fluctuations of the background dipolar Fermi gas. We derive the induced interaction potential to the single-loop order of fluctuations and show that it becomes indeed an anisotropic Ruderman-Kittel-Kasuya-Yosida-type potential which preserves the axial symmetry around the polarization axis. We then solve the two-body problem of impurity atoms interacting via the anisotropic potential and figure out the dependence of bound state and scattering properties on the parameters of dipolar Fermi gas.
Comments:
15 pages, 7 figures
Subjects:
Quantum Gases (cond-mat.quant-gas); Nuclear Theory (nucl-th)
arXiv:
2404.14866 [pdf]
2 citations
08
[Submitted on 23 Apr 2024] (cross-list from hep-ph)
Estimating Longitudinal Polarization of $Λ$ and $Λ ˉ$ Hyperons at Relativistic Energies using Hydrodynamic and Transport models
Bhagyarathi Sahoo🇮🇳 · Captain R. Singh🇮🇳 · Raghunath Sahoo🇮🇳
The global and local spin polarization measurements of $Λ$ ( $Λ ˉ$ ) hyperons by STAR and ALICE Collaborations open up an immense interest in investigating the spin polarization dynamics in heavy-ion collisions. Recent studies suggest the transverse component of the vorticity field is responsible for the global spin polarization. In contrast, the longitudinal component of the vorticity field accounts for the local spin polarization. The local (longitudinal) spin polarization of $Λ$ -hyperons arises due to the anisotropic flows in the transverse plane, indicating a quadrupole pattern of the longitudinal vorticity along the beam direction. In this study, we derive a simple solution relating the longitudinal mean spin vector with the second-order anisotropic flow coefficient due to the thermal shear tensor for an ideal uncharged fluid in a longitudinal boost invariant scenario. The present study focuses on the local spin polarization of $Λ$ and $Λ ˉ$ in Au $+$ Au and Pb $+$ Pb collisions at $s_{N N}$ = 200 GeV and 5.02 TeV, respectively. Further, we explore the azimuthal angle, centrality, and transverse momentum ( $p_{T}$ ) dependence study of longitudinal spin polarization using hydrodynamic and transport models. All these models predict a maximum longitudinal spin polarization in mid-central collisions around 30-50 \% centrality at $p_{T} \approx$ 2.0 - 3.0 GeV/c. These findings on longitudinal spin polarization advocate the existence of a thermal medium in non-central heavy-ion collisions.
Comments:
15 journal pages with 4 captioned figures. Same as the published version in Physica Scripta
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2404.15138 [pdf]
Phys.Scripta(2025)·11 citations

Affiliations

first authorsco-authorsvia INSPIRE

Effective Field Theory for Spontaneously Broken Symmetry

Investigating Ξ resonances from pentaquark perspective

Two-body problem of impurity atoms in dipolar Fermi gas

Estimating Longitudinal Polarization of Λ and Λˉ Hyperons at Relativistic Energies using Hydrodynamic and Transport models

Affiliations

Investigating $Ξ$ resonances from pentaquark perspective

Estimating Longitudinal Polarization of $Λ$ and $Λ ˉ$ Hyperons at Relativistic Energies using Hydrodynamic and Transport models