Nuclear Theory·nucl-th

Friday·November 3, 2023

11 papers—4 primary·7 cross-listed

05
[Submitted on 2 Nov 2023] (cross-list from nucl-ex)
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.
Comments:
12 pages, 6 figures, accepted version by PLB
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2311.00934 [pdf]
PLB(2024)·9 citations
06
[Submitted on 2 Nov 2023] (cross-list from hep-ph)
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.
Comments:
16 pages, 16 tables and 7 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2311.01044 [pdf]
Symmetry(2024)·14 citations
07
[Submitted on 2 Nov 2023] (cross-list from nucl-ex)
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.
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2311.01110 [pdf]
PLB(2023)·14 citations
08
[Submitted on 2 Nov 2023] (cross-list from hep-th)
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.
Comments:
26 pages; v3: minor revisions, submitted to PRD
Subjects:
High Energy Physics — Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); Fluid Dynamics (physics.flu-dyn)
arXiv:
2311.01232 [pdf]
EPJC(2024)·6 citations
09
[Submitted on 2 Nov 2023] (cross-list from gr-qc)
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.
Comments:
12 pages, 10 figures; accepted for publication in Phys. Rev. D
Subjects:
General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2311.01278 [pdf]
PRD(2023)·6 citations
10
[Submitted on 2 Nov 2023] (cross-list from hep-lat)
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.
Comments:
10 pages, 4 figures, proceedings to talk presented at the 40th International Symposium on Lattice Field Theory, July 31st - August 4th 2023, Fermi National Accelerator Laboratory, Batavia, Illinois, USA. arXiv admin note: text overlap with arXiv:2211.17009
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2311.01322 [pdf]
2 citations
11
[Submitted on 2 Nov 2023] (cross-list from hep-ph)
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.
Comments:
5 pages and the appendix. Accepted by Physical Review Letters
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2311.01391 [pdf]
PRL(2024)·38 citations

Affiliations

first authorsco-authorsvia INSPIRE

Measurements of charged-particle multiplicity dependence of higher-order net-proton cumulants in p+p collisions at s​= 200 GeV from STAR at RHIC

Hidden-charm pentaquarks with strangeness in a chiral quark model

Electromagnetic moments of the antimony isotopes 112−133Sb

Third-order relativistic fluid dynamics at finite density in a general hydrodynamic frame

Rotating Bose-Einstein Condensate Stars at finite temperature

Lattice QCD Constraints on the Fourth Mellin Moment of the Pion Light Cone Distribution Amplitude using the HOPE method

Transverse Momentum Distributions from Lattice QCD without Wilson Lines

Affiliations

Measurements of charged-particle multiplicity dependence of higher-order net-proton cumulants in $p$ + $p$ collisions at $s =$ 200 GeV from STAR at RHIC

Electromagnetic moments of the antimony isotopes $^{112 - 133}$ Sb