Nuclear Theory·nucl-th

Friday·November 3, 2023

11 papers—4 primary·7 cross-listed

01
Compiled Properties of Nucleonic Matter and Nuclear and Neutron Star Models from Non-Relativistic and Relativistic Interactions
Boyang Sun · Saketh Bhattiprolu · James M. Lattimer
This paper compiles the model parameters and zero-temperature properties of an extensive collection of published theoretical nuclear interactions, including 255 non-relativistic (Skyrme-like) forces, 270 relativistic mean field (RMF) and point-coupling (RMF-PC) forces, and 13 Gogny-like forces. This forms the most exhaustive tabulation of model parameters to date. The properties of uniform symmetric matter and pure neutron matter at the saturation density are determined. Symmetry properties found from the second-order term of a Taylor expansion in neutron excess are compared to the energy difference of pure neutron and symmetric nuclear matter at the saturation density. Selected liquid-droplet model parameters, including the surface tension and surface symmetry energy, are determined for semi-infinite surfaces. Theoretical liquid droplet model neutron skin thicknesses of the neutron-rich closed-shell nuclei $^{48}$ Ca and $^{208}$ Pb are compared to published theoretical Hartree-Fock and experimental results. A similar comparison is made between theoretical liquid-droplet and experimental values of dipole polarizabilities. In addition, radii, binding energies, moments of inertia and tidal deformabilities of 1.2, 1.4 and 1.6 M $_{⊙}$ neutron stars are computed. An extensive correlation analysis of bulk matter, nuclear structure, and low-mass neutron star properties is performed and compared to nuclear experiments and astrophysical observations.
nucl-thastro-ph.HEPRC(2024)·45 citations
02
Barrier penetration in a discrete basis formalism
K. Hagino
A standard way to solve a Schrödinger equation is to discreteize the radial coordinates and apply a numerical method for a differential equation, such as the Runge-Kutta method or the Numerov method. Here I employ a discrete basis formalism based on a finite mesh method as a simpler alternative, with which the numerical computation can be easily implemented by ordinary linear algebra operations. I compare the numerical convergence of the Numerov integration method to the finite mesh method for calculating penetrabilities of a one-dimensional potential barrier, and show that the latter approach has better convergence properties.
nucl-th0 citations
03
Study of bulk properties of the system formed in U+U collisions at $s_{N N}$ =~2.12~GeV using JAM model
Aswini Kumar Sahoo🇮🇳 · Xionghong He🇨🇳 · Yasushi Nara🇯🇵 · Subhash Singha🇨🇳
The Lanzhou Cooling-Storage-Ring facility is set to conduct experiments involving Uranium-Uranium collisions at the center of mass energies ranging from 2.12 to 2.4 GeV. Our investigation is focused on various bulk observables, which include charged particle multiplicity ( $N_{ch}$ ), average transverse momentum ( $⟨ p_{T} ⟩$ ), initial eccentricity ( $ϵ_{n}$ ), and flow harmonics ( $v_{n}$ ), for different orientations of U+U collisions within the range of $0^{\circ} < θ < 12 0^{\circ}$ at $s_{N N} = 2.12$ GeV ( $p_{l ab}$ = 500 MeV). Among the various collision configurations at this energy, the tip-tip scenario emerged with the highest average charged particle multiplicity, denoted as $⟨ N_{ch} ⟩$ . Notably, both the second and third-order eccentricities, $ϵ_{2, 3}$ , revealed intricate patterns as they varied with impact parameter across distinct configurations. The tip-tip configuration displayed the most pronounced magnitude of rapidity-odd directed flow ( $v_{1}$ ), whereas the body-body configuration exhibited the least pronounced magnitude. Concerning elliptic flow ( $v_{2}$ ) near mid-rapidity ( $η < 1.0$ ), a negative sign is observed for all configurations except for the side-side exhibited a distinctly positive sign. Within the spectrum of configurations, the body-body scenario displayed the highest magnitude of $v_{2}$ . For reaction plane correlated triangular flow ( $v_{3}$ ), the body-body configuration emerged with the largest magnitude while the side-side exhibited the smallest magnitude. Our study seeks to establish a fundamental understanding of various U+U collision configurations in preparation for the forthcoming CEE experiment.
nucl-thhep-exnucl-exPRC(2024)·2 citations
04
Polarization effects in elastic deuteron-electron scattering
G. I. Gakh🇺🇦 · M.I. Konchatni🇺🇦 · N.P. Merenkov🇺🇦 · E. Tomasi-Gustafsson🇫🇷 · A. G. Gakh🇺🇦
The differential cross section and polarization observables for the elastic reaction induced by deuteron scattering off electrons at rest are calculated in the one-photon-exchange (Born) approximation. Specific attention is given to the kinematical conditions, that is, to the specific range of incident energy and transferred momentum. The specific interest of this reaction is to access very small transferred momenta. Numerical estimates are given for polarization observables that describe the of single- and double-spin effects, provided that the polarization components (both, vector and tensor) of each particle in the reaction are determined in the rest frame of the electron target.
nucl-thhep-phPRC(2024)·1 citation
05
Measurements of charged-particle multiplicity dependence of higher-order net-proton cumulants in $p$ + $p$ collisions at $s =$ 200 GeV from STAR at RHIC
STAR Collaboration: M. I. Abdulhamid🇪🇬 · B. E. Aboona🇺🇸 · J. Adam🇨🇿 · L. Adamczyk🇵🇱 · J. R. Adams · I. Aggarwal🇮🇳 · M. M. Aggarwal🇮🇳 · Z. Ahammed · E. C. Aschenauer🇺🇸 · S. Aslam🇮🇳 · J. Atchison🇺🇸 · V. Bairathi🇨🇱 and 350 other authors
We report on the charged-particle multiplicity dependence of net-proton cumulant ratios up to sixth order from $s = 200$ GeV $p$ + $p$ collisions at the Relativistic Heavy Ion Collider (RHIC). The measured ratios $C_{4} / C_{2}$ , $C_{5} / C_{1}$ , and $C_{6} / C_{2}$ decrease with increased charged-particle multiplicity and rapidity acceptance. Neither the Skellam baselines nor PYTHIA8 calculations account for the observed multiplicity dependence. In addition, the ratios $C_{5} / C_{1}$ and $C_{6} / C_{2}$ approach negative values in the highest-multiplicity events, which implies that thermalized QCD matter may be formed in $p$ + $p$ collisions.
↳ nucl-exhep-exhep-phnucl-thPLB(2024)·9 citations
06
Hidden-charm pentaquarks with strangeness in a chiral quark model
Gang Yang🇨🇳 · Jialun Ping🇨🇳 · Jorge Segovia🇪🇸
The LHCb collaboration has recently announced the discovery of two hidden-charm pentaquark states with also strange quark content, $P_{cs} (4338)$ and $P_{cs} (4459)$ ; its analysis points towards having both hadrons isospin equal to zero and spin-parity quantum numbers $\frac{1}{2}^{-}$ and $\frac{3}{2}^{-}$ , respectively. We perform herein a systematical investigation of the $q q sc c ˉ$ $(q = u, d)$ system by means of a chiral quark model, along with a highly accurate computational method, the Gaussian expansion approach combined with the complex-scaling technique. Baryon-meson configurations in both singlet- and hidden-color channels are considered. The $P_{cs} (4338)$ and $P_{cs} (4459)$ signals can be well identified as molecular bound states with dominant components $Λ J / ψ$ $(60%)$ and $Ξ_{c} D$ $(23%)$ for the lowest-energy case and $Ξ_{c} D^{*}$ $(72%)$ for the highest-energy one. Besides, it seems that some narrow resonances can be also found in each allowed $I (J^{P})$ -channel in the energy region of $4.6 - 5.5$ GeV, except for the $1 (\frac{1}{2}^{-})$ where a shallow bound state with dominant $Ξ_{c}^{*} D^{*}$ structure is obtained at $4673$ MeV with binding energy $E_{B} = - 3$ MeV. These exotic states are expected to be confirmed in future high energy experiments.
↳ hep-phhep-exhep-latnucl-ex+1Symmetry(2024)·14 citations
07
Electromagnetic moments of the antimony isotopes $^{112 - 133}$ Sb
S. Lechner🇨🇭 · T. Miyagi🇩🇪 · Z.Y. Xu🇧🇪 · M.L. Bissell🇬🇧 · K. Blaum🇩🇪 · B. Cheal🇬🇧 · C.S. Devlin🇬🇧 · R.F. Garcia Ruiz🇨🇭 · J.S.M. Ginges🇦🇺 · H. Heylen🇨🇭 · J.D. Holt🇨🇦 · P. Imgram🇩🇪 and 13 other authors
Nuclear moments of the antimony isotopes $^{113 - 133}$ Sb are measured by collinear laser spectroscopy and used to benchmark phenomenological shell-model and \textit{ab initio} calculations in the valence-space in-medium similarity renormalization group (VS-IMSRG). The shell-model calculations reproduce the electromagnetic moments over all Sb isotopes when suitable effective $g$ -factors and charges are employed. Good agreement is achieved by VS-IMSRG for magnetic moments on the neutron-deficient side for both odd-even and odd-odd Sb isotopes while its results deviate from experiment on the neutron-rich side. When the same effective $g$ -factors are used, VS-IMSRG agrees with experiment nearly as well as the shell model. Hence, the wave functions are very similar in both approaches and missing contributions to the M1 operator are identified as the cause of the discrepancy of VS-IMSRG with experiment. Electric quadrupole moments remain more challenging for VS-IMSRG.
↳ nucl-exnucl-thPLB(2023)·14 citations
08
Third-order relativistic fluid dynamics at finite density in a general hydrodynamic frame
Saulo M. Diles🇧🇷 · Alex S. Miranda🇧🇷 · Luis A. H. Mamani🇧🇷 · Alex M. Echemendia🇧🇷 · Vilson T. Zanchin🇧🇷
The motion of water is governed by the Navier-Stokes equations, which are complemented by the continuity equation to ensure local mass conservation. In this work, we construct the relativistic generalization of these equations through a gradient expansion for a fluid with conserved charge in a curved $d$ -dimensional spacetime. We adopt a general hydrodynamic frame approach and introduce the Irreducible-Structure (IS) algorithm, which is based on derivatives of both the expansion scalar and the shear and vorticity tensors. By this method, we systematically generate all permissible gradients up to a specified order and derive the most comprehensive constitutive relations for a charged fluid, accurate to third-order gradients. These constitutive relations are formulated to apply to ordinary, non-conformal, and conformally invariant charged fluids. Furthermore, we examine the hydrodynamic frame dependence of the transport coefficients for a non-conformal charged fluid up to the third order in the gradient expansion. The frame dependence of the scalar, vector, and tensor parts of the constitutive relations is obtained in terms of the field redefinitions of the fundamental hydrodynamic variables. Managing these frame dependencies is challenging due to their non-linear character. However, in the linear regime, these higher-order transformations become tractable, enabling the identification of a set of frame-invariant coefficients. An advantage of employing these coefficients is the possibility of studying the linear equations of motion in any chosen frame and, hence, we apply this approach to the Landau frame. Subsequently, these linear equations are solved in momentum space, yielding dispersion relations for shear, sound, and diffusive modes for a non-conformal charged fluid, expressed in terms of the frame-invariant transport coefficients.
↳ hep-thgr-qchep-phnucl-th+1EPJC(2024)·6 citations
09
Rotating Bose-Einstein Condensate Stars at finite temperature
P. S. Aswathi🇮🇳 · P. S. Keerthi🇮🇳 · O. P. Jyothilakshmi🇮🇳 · Lakshmi J. Naik🇮🇳 · V. Sreekanth🇮🇳
We study the effect of temperature on the global properties of static and slowly rotating self-gravitating Bose-Einstein condensate (BEC) stars within general relativity. We employ a recently developed temperature dependent BEC equation of state (EoS) to describe the stellar matter by assuming that the condensate can be described by a non-relativistic EoS. Stellar profiles are obtained using general relativistic Hartle-Thorne slow rotation approximation equations. We find that with increasing temperatures mass-radius values are found to be decreasing for the static and rotating cases; though presence of temperature supports high mass values at lower central densities. Countering effects of rotation and temperature on the BEC stellar structure have been analysed and quantified. We report that inclusion of temperature has significant effect on the rotating stellar profiles but negligible effect on the maximum mass, as in the case of static system. We have also studied the effect of EoS parameters -- boson mass and strength of the self-interaction -- on global properties of static and rotating BEC stars, in presence of temperature.
↳ gr-qcastro-ph.HEhep-phnucl-thPRD(2023)·6 citations
10
Lattice QCD Constraints on the Fourth Mellin Moment of the Pion Light Cone Distribution Amplitude using the HOPE method
William Detmold🇺🇸 · Anthony V. Grebe🇺🇸 · Issaku Kanamori🇯🇵 · C.-J. David Lin🇹🇼 · Robert J. Perry🇪🇸 · Yong Zhao🇺🇸
The light-cone distribution amplitude (LCDA) of the pion contains information about the parton momentum carried by the quarks and is an important theoretical input for various predictions of exclusive processes at high energy, including the pion electromagnetic form factor. Progress towards constraining the fourth Mellin moment of the LCDA using the heavy-quark operator product expansion (HOPE) method is presented.
↳ hep-lathep-phnucl-th2 citations
11
Transverse Momentum Distributions from Lattice QCD without Wilson Lines
Yong Zhao🇺🇸
The transverse-momentum-dependent distributions (TMDs), which are defined by gauge-invariant 3D parton correlators with staple-shaped lightlike Wilson lines, can be calculated from quark and gluon correlators fixed in the Coulomb gauge on a Euclidean lattice. These quantities can be expressed gauge-invariantly as the correlators of Coulomb-gauge-dressed fields, which reduce to the standard TMD correlators under principal-value prescription in the infinite boost limit. In the framework of Large-Momentum Effective Theory, a quasi-TMD defined from such correlators in a large-momentum hadron state can be matched to the TMD via a factorization formula, whose exact form is derived using Soft Collinear Effective Theory and verified at one-loop order. Compared to the currently used gauge-invariant correlators, this new method can substantially improve statistical precision and simplify renormalization for the time-reversal-even TMDs, which will greatly enhance the predicative power of lattice QCD in the non-perturbative region.
↳ hep-phhep-exhep-lathep-th+1PRL(2024)·38 citations

Affiliations

first authorsco-authorsvia INSPIRE