Nuclear Theory·nucl-th

Monday·January 29, 2024

11 papers—2 primary·9 cross-listed

01
[Submitted on 26 Jan 2024]
Generalized coherent states satisfying the Pauli principle in a nuclear cluster model
Takayuki Myo · Kiyoshi Kato
We propose a new basis state, which satisfies the Pauli principle in the nuclear cluster model. The basis state is defined as the generalized coherent state of the harmonic oscillator wave function using a pair of the creation operators and is orthogonal to the Pauli-forbidden states having smaller quanta. In the coherent basis state, the range parameter is changeable and controls the radial dilation. This property is utilized for the precise description of the relative motion between nuclear clusters. We show the reliability of this framework for the $2 α$ system of $^{8}$ Be in the semi-microscopic orthogonality condition model. We obtain the resonances and non-resonant continuum states of $2 α$ with complex scaling. The resonance solutions and the phase shifts of the $α$ - $α$ scattering agree with those using the conventional projection operator method to remove the Pauli-forbidden states. We further discuss the extension of the present framework to the multi- $α$ cluster systems using the SU(3) wave functions.
Comments:
11 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2401.14572 [pdf]
PRC(2024)·2 citations
02
[Submitted on 26 Jan 2024]
Strongly interacting matter in a sphere at nonzero magnetic field
Bing-Jun Zuo🇨🇳 · Zheng Zhang🇨🇳 · Chao Shi🇨🇳 · Yong-Feng Huang🇨🇳
We investigate the chiral phase transition within a sphere under a uniform background magnetic field. The Nambu--Jona-Lasinio (NJL) model is employed and the MIT boundary condition is imposed for the spherical confinement. Using the wave expansion method, the diagonalizable Hamiltonian and energy spectrum are derived for the system. By solving the gap equation in the NJL model, the influence of magnetic field on quark matter in a sphere is studied. It is found that inverse magnetic catalysis occurs at small radii, while magnetic catalysis occurs at large radii. Additionally, both magnetic catalysis and inverse magnetic catalysis are observed at the intermediate radii ( $R \approx 4$ fm).
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Theory (hep-th)
arXiv:
2401.14646 [pdf]
PRD(2024)·0 citations
03
[Submitted on 23 Jan 2024] (cross-list from astro-ph.HE)
Constraining the mass of fermionic dark matter from its feeble interaction with hadronic matter via dark mediators in neutron stars
Atanu Guha🇰🇷 · Debashree Sen🇰🇷
Considering ten well-known relativistic mean field models, we invoke feeble interaction between hadronic matter and fermionic dark matter (DM) $χ$ via new physics scalar ( $ϕ$ ) and vector ( $ξ$ ) mediators in neutron star core, thereby forming DM admixed neutron stars (DMANSs). The chosen masses of the DM fermion ( $m_{χ}$ ) and the mediators ( $m_{ϕ}$ and $m_{ξ}$ ) are consistent with the self-interaction constraint from Bullet cluster while their respective couplings ( $y_{ϕ}$ and $y_{ξ}$ ) are also constrained by the present day relic abundance. Assuming that both $ϕ$ and $ξ$ contribute equally to the relic abundance, we compute the equation of state of the DMANSs and consequently their structural properties. We found that for a particular (constant) DM density, the presence of lighter DM results in more massive DMANSs with larger radius. In the light of the various recent constraints like those from the massive pulsar PSR J0740+6620, the gravitational wave (GW170817) data and the results of NICER experiments for PSR J0030+0451 and PSR J0740+6620, we provide a bound on $m_{χ}$ within the framework of the present work as $m_{χ} \approx$ (0.1 $-$ 30) GeV for a wide range of fixed DM Fermi momenta $k_{F}^{χ}$ =(0.01 $-$ 0.07) GeV. In the case of the hadronic models that yield larger radii corresponding to the low mass neutron stars in the no-DM scenario, interaction with comparatively heavier DM fermion is necessary in order to ensure that the DMANSs obtained with such models satisfy the radius constraints from both GW170817 and NICER data for PSR J0030+0451.
Comments:
$k_{F}^{χ}$ = 0.06 GeV has been corrected to $k_{F}^{χ}$ = 0.07 GeV in all of the occurrences. TABLE III and Figure 10 have also been corrected in version 2
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2401.14419 [pdf]
PRD(2024)·28 citations
04
[Submitted on 26 Jan 2024] (cross-list from hep-ph)
Role of Coulomb interaction in elastic pion-proton scattering from holography
Yu-Peng Zhang🇨🇳 · Xun Chen🇨🇳 · Xiao-Hua Li🇨🇳 · Akira Watanabe🇨🇳
Differential cross sections of the elastic pion-proton scattering are investigated at very small momentum transfer in a holographic QCD model, considering both the strong and Coulomb interaction in the Regge regime. The strong interaction is described by the Pomeron and Reggeon exchange, and the Coulomb interaction is characterized by the one photon exchange. The two interactions are linked through an interference term and we only need to determine a single adjustable parameter involved in this term. As to the parameters for the strong interaction, we can utilize the values determined in the previous studies. The differential cross sections can be predicted without any additional parameters, and it is shown that our predictions are consistent with the experimental data. We explicitly show the momentum transfer dependence for the interference effect. The energy dependence of the contribution ratios for each component is also discussed.
Comments:
24 pages, 5 figures, version accepted for publication in Phys. Rev. D
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2401.14649 [pdf]
PRD(2024)·4 citations
05
[Submitted on 26 Jan 2024] (cross-list from hep-ph)
Positron supercritical resonances and spontaneous positron creation in slow collisions of heavy nuclei
D.A. Telnov🇷🇺 · N.K. Dulaev🇷🇺 · Y.S. Kozhedub🇷🇺 · I.A. Maltsev🇷🇺 · R.V. Popov🇷🇺 · I.I. Tupitsyn🇷🇺 · V.M. Shabaev🇷🇺
We present a theoretical and computational study of positron supercritical resonances in systems consisting of two highly-charged bare nuclei. The resonance positions and widths depending on the internuclear separation are calculated with the help of the complex-scaling generalized pseudospectral method in modified prolate spheroidal coordinates. The results are applied to estimate the probability of spontaneous positron creation in slow U $^{92 +}$ --U $^{92 +}$ and Cm $^{96 +}$ --Cm $^{96 +}$ collisions.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2401.14735 [pdf]
Phys.Atom.Nucl.(2024)·2 citations
06
[Submitted on 26 Jan 2024] (cross-list from hep-ph)
Asymmetric collisions in MadGraph5_aMC@NLO
Laboni Manna🇵🇱 · Anton Safronov🇵🇱 · Carlo Flore🇮🇹 · Daniel Kikola🇵🇱 · Jean-Philippe Lansberg🇫🇷 · Olivier Mattelaer🇧🇪
We will gain unprecedented, high-accuracy insights into the internal structure of the atomic nucleus thanks to lepton-hadron collision studies in the coming years at the Electron-Ion-Collider (EIC) in the United States. A good control of radiative corrections is necessary for the EIC to be fully exploited and to extract valuable information from various measurements. We present our extension of photoproduction at fixed order in MadGraph5_aMC@NLO, a widely used framework for (next-to-)leading order calculations at the Large Hadron Collider (LHC). It applies to electron-hadron collisions, in which the quasi-real photon comes from an electron as well as to proton-nucleus and nucleus-nucleus collisions.
Comments:
2 references added and a couple of sentences modified
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2401.14741 [pdf]
PoS(2024)·1 citation
07
[Submitted on 26 Jan 2024] (cross-list from hep-ph)
Study of spin polarization dependence on rapidity, transverse momentum, and azimuthal angle
Wojciech Florkowski🇵🇱 · Radoslaw Ryblewski🇵🇱 · Rajeev Singh🇺🇸
We investigate the spacetime evolution of spin polarization within a hydrodynamic framework based on the de Groot--van Leeuwen--van Weert expressions for energy-momentum and spin tensors. The system's deviation from boost invariance results in the interplay of different spin polarization components, impacting spin observables. We specifically examine the transverse momentum, azimuthal angle, and rapidity dependence of the mean spin polarization vector of $Λ$ hyperons. Our results qualitatively align with other models and experimental data on global spin polarization rapidity dependence. While the quadrupole structure is absent in the longitudinal component at midrapidity, our analysis reveals non-trivial signal at forward rapidities that differs from predictions based on the Bjorken expansion.
Comments:
Contribution to SPIN 2023
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2401.14789 [pdf]
PoS(2024)·0 citations
08
[Submitted on 26 Jan 2024] (cross-list from hep-ph)
Benchmark calculations of fully heavy compact and molecular tetraquark states
Wei-Lin Wu🇨🇳 · Yan-Ke Chen🇨🇳 · Lu Meng🇩🇪 · Shi-Lin Zhu🇨🇳
We calculate the mass spectrum of the S-wave fully heavy tetraquark systems $QQ Q ˉ Q ˉ (Q = c, b)$ with both normal $(J^{P C} = 0^{++}, 1^{+-}, 2^{++})$ and exotic $(J^{P C} = 0^{+-}, 1^{++}, 2^{+-})$ C-parities using three different quark potential models (AL1, AP1, BGS). The exotic C-parity systems refer to the ones that cannot be composed of two S-wave ground heavy quarkonia. We incorporate the molecular dimeson and compact diquark-antidiquark spatial correlations simultaneously, thereby discerning the actual configurations of the states. We employ the Gaussian expansion method to solve the four-body Schrödinger equation, and the complex scaling method to identify the resonant states. The mass spectra in three different models qualitatively agree with each other. We obtain several resonant states with $J^{P C} = 0^{++}, 1^{+-}, 2^{++}, 1^{++}$ in the mass region $(6.92, 7.30) GeV$ , some of which are good candidates of the experimentally observed $X (6900)$ and $X (7200)$ . We also obtain several exotic C-parity zero-width states with $J^{P C} = 0^{+-}$ and $2^{+-}$ . These zero-width states have no corresponding S-wave diquarkonium threshold and can only decay strongly to final states with P-wave quarkonia. With the notation $T_{4 Q, J (C)} (M)$ , we deduce from the root mean square radii that the $X (7200)$ candidates $T_{4 c, 0 (+)} (7173), T_{4 c, 2 (+)} (7214)$ and the state $T_{4 c, 1 (-)} (7191)$ look like molecular states although most of the resonant and zero-width states are compact states.
Comments:
16 pages, 6 figures, 10 tables. Version accepted by PRD
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2401.14899 [pdf]
PRD(2024)·46 citations
09
[Submitted on 26 Jan 2024] (cross-list from hep-ph)
Direct WIMP detection rates for transitions in isomeric nuclei
M.V Smirnov🇩🇪 · G. Yang🇺🇸 · Yu.N. Novikov🇷🇺 · J.D. Vergados🇬🇷 · D. Bonatsos🇬🇷
The direct detection of dark matter constituents, in particular the weakly interacting massive particles (WIMPs), is central to particle physics and cosmology. In this paper we study WIMP induced transitions from isomeric nuclear states for two possible isomeric candidates: $^{180} Ta$ and $^{166} Ho$ . The experimental setup, which can measure the possible decay of $^{180} Ta$ induced by WIMPs, was proposed. The corresponding estimates of the half-life of $^{180} Ta$ are given in the sense that the WIMP-nucleon interaction can be interpreted as ordinary radioactive decay.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2401.14917 [pdf]
NPB(2024)·4 citations
10
[Submitted on 26 Jan 2024] (cross-list from astro-ph.HE)
Neutron-star Measurements in the Multi-messenger Era
Stefano Ascenzi🇪🇸 · Vanessa Graber🇪🇸 · Nanda Rea🇪🇸
Neutron stars are compact and dense celestial objects that offer the unique opportunity to explore matter and its interactions under conditions that cannot be reproduced elsewhere in the Universe. Their extreme gravitational, rotational and magnetic energy reservoirs fuel the large variety of their emission, which encompasses all available multi-messenger tracers: electromagnetic and gravitational waves, neutrinos, and cosmic rays. However, accurately measuring global neutron-star properties such as mass, radius, and moment of inertia poses significant challenges. Probing internal characteristics such as the crustal composition or superfluid physics is even more complex. This article provides a comprehensive review of the different methods employed to measure neutron-star characteristics and the level of reliance on theoretical models. Understanding these measurement techniques is crucial for advancing our knowledge of neutron-star physics. We also highlight the importance of employing independent methods and adopting a multi-messenger approach to gather complementary data from various observable phenomena as exemplified by the recent breakthroughs in gravitational-wave astronomy and the landmark detection of a binary neutron-star merger. Consolidating the current state of knowledge on neutron-star measurements will enable an accurate interpretation of the current data and errors, and better planning for future observations and experiments.
Comments:
48 pages (including 11 pages of references), 10 figures, 2 tables; invited review for special issue of Astroparticle Physics on 'Gravitational Waves and Multi-messenger Astrophysics'
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM); Solar and Stellar Astrophysics (astro-ph.SR); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
2401.14930 [pdf]
Astropart.Phys.(2024)·39 citations
11
[Submitted on 26 Jan 2024] (cross-list from hep-ph)
A New Determination of the (Z,A) Dependence of Coherent Muon-to-Electron Conversion
Léo Borrel🇺🇸 · David G. Hitlin🇺🇸 · Sophie Middleton🇺🇸
Should muon-to-electron conversion in the field of a nucleus be found in the current generation of experiments, the measurement of the atomic number dependence of the process will become an important experimental goal. We present a new treatment of the (Z,A) dependence of coherent muon-to-electron conversion in 236 isotopes. Our approach differs from previous treatments in several ways. Firstly, we include the effect of permanent quadrupole deformation on the charged lepton flavor violating matrix elements, using the method of Barrett moments. This method also enables the addition of muonic X-ray nuclear size and shape determinations of the charge distribution to the electron scattering results used previously. Secondly, we employ a Hartree-Bogoliubov model to calculate neutron-related matrix elements for even-even nuclei. This takes into account the quadrupole deformation of the neutron distributions and the fact that neutrons are, in general, in different shell model orbits than protons. The calculated conversion rates differ from previous calculations, particularly in the region of large permanent quadrupole deformation. Finally, we propose an alternative normalization of the muon-to-electron conversion rated, which related more closely to what a given experiment acturally measures, and better separate lepton physics from nuclear physics effects.
Comments:
23 pages, 12 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2401.15025 [pdf]
NPA(2025)·13 citations

Affiliations

first authorsco-authorsvia INSPIRE