Nuclear Theory·nucl-th

Tuesday·January 2, 2024

11 papers—5 primary·6 cross-listed

06
[Submitted on 30 Dec 2023] (cross-list from hep-ph)
Doubly heavy tetraquark states in a mass splitting model
Shi-Yuan Li🇨🇳 · Yan-Rui Liu🇨🇳 · Zi-Long Man🇨🇳 · Zong-Guo Si🇨🇳 · Jing Wu🇨🇳
Treating the $X (4140)$ as a compact $J^{P C} = 1^{++}$ $cs c ˉ s ˉ$ state and using its mass as a reference scale, we systematically estimate the masses of doubly heavy tetraquark states $QQ q ˉ q ˉ$ where $Q = c, b$ and $q = u, d, s$ . Their decay properties are studied with a simple rearrangement scheme. Based on our results, the lowest $I (J^{P}) = 0 (1^{+})$ $bb n ˉ n ˉ$ state is a stable tetraquark about 20 MeV below the $B ˉ^{*} B ˉ$ threshold. The mass and width of the low-mass $0 (1^{+})$ $cc n ˉ n ˉ$ ( $n = u, d$ ) tetraquark are compatible with the $T_{cc} (3875)^{+}$ observed by the LHCb Collaboration. The location of the lowest $0 (0^{+})$ and $0 (1^{+})$ $b c n ˉ n ˉ$ states are found to be close to the $B ˉ D$ and $B ˉ^{*} D$ thresholds, respectively. We hope that the predicted ratios between partial widths of different channels may be helpful to identify compact tetraquark states from future measurements.
Comments:
18 pages,3 figures,11 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2401.00115 [pdf]
PRD(2024)·16 citations
07
[Submitted on 30 Dec 2023] (cross-list from cond-mat.mes-hall)
Spin current generation due to differential rotation
Takumi Funato · Shunichiro Kinoshita · Norihiro Tanahashi · Shin Nakamura · Mamoru Matsuo
We study nonequilibrium spin dynamics in differentially rotating systems, deriving an effective Hamiltonian for conduction electrons in the comoving frame. In contrast to conventional spin current generation mechanisms that require vorticity, our theory describes spins and spin currents arising from differentially rotating systems regardless of vorticity. We demonstrate the generation of spin currents in differentially rotating systems, such as liquid metals with Taylor-Couette flow. Our alternative mechanism will be important in the development of nanomechanical spin devices.
Comments:
12pages, 3figures
Subjects:
Mesoscale and Nanoscale Physics (cond-mat.mes-hall); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2401.00174 [pdf]
PRB(2025)·3 citations
08
[Submitted on 30 Dec 2023] (cross-list from hep-ph)
In-medium mass shift of two-flavored heavy mesons, $B_{c}$ , $B_{c}^{*}$ , $B_{s}$ , $B_{s}^{*}$ , $D_{s}$ and $D_{s}^{*}$
G. N. Zeminiani🇧🇷 · S. L. P. G. Beres🇧🇷 · K. Tsushima🇧🇷
For the first time, we estimate the in-medium mass shift of the two-flavored heavy mesons $B_{c}, B_{c}^{*}, B_{s}, B_{s}^{*}, D_{s}$ and $D_{s}^{*}$ in symmetric nuclear matter. The estimates are made by evaluating the lowest order one-loop self-energies. The enhanced excitations of intermediate state heavy-light mesons in symmetric nuclear matter are the origin of their negative mass shift. This negative mass shift may be regarded as a signature of partial restoration of chiral symmetry in an empirical sense because the origin of the negative mass shift in the study is not directly related to the chiral symmetry mechanism. Our results show that the magnitude of the mass shift for the $B_{c}$ meson ( $b ˉ c$ or $b c ˉ$ ) is larger than those of the $η_{c} (c ˉ c)$ and $η_{b} (b ˉ b)$ , different from a naive expectation that it would be in between them. While, that of the $B_{c}^{*}$ shows the in between of the $J / ψ$ and $Υ$ . We observe that the lighter vector meson excitation in each meson self-energy gives a dominant contribution for the corresponding meson mass shift, $B_{c}, B_{s},$ and $D_{s}$ .
Comments:
24 pages, 21 figures (44 .eps files for figures), changes: unnecessary files removed, 1 figure corrected, 2 figures added
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:
2401.00250 [pdf]
PRD(2024)·8 citations
09
[Submitted on 30 Dec 2023] (cross-list from nucl-ex)
Measurements of $p - Λ$ and $d - Λ$ correlations in 3 GeV Au+Au collisions at STAR
Yu Hu (for the STAR Collaborations)🇺🇸
Heavy-ion collisions provide a unique opportunity to explore nucleon-hyperon (N-Y) interactions through two-particle correlations. The $p - Λ$ and $d - Λ$ correlations shed light on both N-Y two-body and N-N-Y three-body interactions, which is crucial for understanding neutron star properties. We present the high precision measurement of $p - Λ$ and the first measurement of $d - Λ$ correlation with $s_{_{NN}} =$ 3 GeV Au+Au collisions at STAR. Using the Lednicky-Lyuboshitz formalism, we characterized emission source size, the scattering length ( $f_{0}$ ), and the effective range ( $d_{0}$ ) of $p - Λ$ and $d - Λ$ interactions. Using the $f_{0}$ and $d_{0}$ extracted from two spin states in $d - Λ$ correlation, the parameters from the doublet state indicate the hypertriton binding energy is consistent with the current average of world measurements.
Comments:
4 pages, 3 figures, Quark Matter 2023 (QM23) proceedings
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2401.00319 [pdf]
EPJ Web Conf.(2024)·10 citations
10
[Submitted on 31 Dec 2023] (cross-list from hep-ph)
Bulk medium properties of heavy-ion collisions from the beam energy scan with a multistage hydrodynamic model
Lipei Du🇨🇦
We introduce a method to reconstruct full rapidity distributions of charged particle multiplicity and net proton yields, crucial for constraining the longitudinal dynamics of nuclear matter created in the beam energy scan program. Employing rapidity distributions within a multistage hydrodynamic model calibrated for Au+Au collisions at $s_{NN} = 7.7 - 200$ GeV, we estimate the total energy and baryon number deposited into the collision fireball, offering insights into initial dynamics and the identification of nuclear remnants. We explore the potential of rapidity-dependent measurements in probing equations of state at finite chemical potentials. Furthermore, we compare the freeze-out parameters derived from both hydrodynamics and thermal models, highlighting that the parameters extracted via thermal models represent averaged properties across rapidities.
Comments:
v1: 15 pages, 12 figures; v2: figs. 2 and 4 slightly adjusted; v3: Title slightly changed. A few short discussions were added, but there are no changes to the results or conclusions. Published in PRC
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2401.00596 [pdf]
PRC(2024)·17 citations
11
[Submitted on 1 Jan 2024] (cross-list from hep-ph)
Collision energy dependence of source sizes for primary and secondary pions at NICA energies
Alejandro Ayala🇲🇽 · Santiago Bernal-Langarica🇲🇽 · Isabel Dominguez🇲🇽 · Ivonne Maldonado🇷🇺 · Maria Elena Tejeda-Yeomans🇲🇽
We study the evolution of the two-pion correlation function parameters with collision energy in the context of relativistic heavy-ion collisions within the NICA energy range. To this end, we perform UrQMD simulations in the cascade mode to produce samples of pions from $5 \times 1 0^{6}$ Bi+Bi collisions for each of the studied energies. The effects of the quantum-statistical correlations are introduced using the correlation afterburner code CRAB. We fit the correlation function using Gaussian, exponential and symmetric Lévy shapes and show that for all collision energies the latter provides the best fit. We separate the sample into pions coming from primary processes and pions originating from the decay of long-lived resonances, and show that the source size for the latter is significantly larger than for the former. The source size for the secondaries, is similar but in general larger than the size for the whole pion sample. To further characterize the pion source, we also simulate the effects of a non-ideal detector introducing a momentum smearing parameter, representing the minimum pair momentum and thus a maximum source size that can be resolved. The values of the correlation function intercept parameter are therefore modified from the values they attain for the perfect detector case. Using the core-halo picture of the source, we show that the values of the intercept parameter are influenced by the presence of a significant fraction of core pions coming from the decay of long-lived but slow-moving resonances. These findings serve as a benchmark to compare with future Monte Carlo studies that consider an Equation of State and thus allow for a phase transition within the studied energy domain.
Comments:
8 pages, 10 figures. Version accepted to appear in EPJ-A
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2401.00619 [pdf]
EPJA(2024)·6 citations

Affiliations

first authorsco-authorsvia INSPIRE

Doubly heavy tetraquark states in a mass splitting model

Spin current generation due to differential rotation

In-medium mass shift of two-flavored heavy mesons, Bc​, Bc∗​, Bs​, Bs∗​, Ds​ and Ds∗​

Measurements of p−Λ and d−Λ correlations in 3 GeV Au+Au collisions at STAR

Bulk medium properties of heavy-ion collisions from the beam energy scan with a multistage hydrodynamic model

Collision energy dependence of source sizes for primary and secondary pions at NICA energies

Affiliations

In-medium mass shift of two-flavored heavy mesons, $B_{c}$ , $B_{c}^{}$ , $B_{s}$ , $B_{s}^{}$ , $D_{s}$ and $D_{s}^{*}$

Measurements of $p - Λ$ and $d - Λ$ correlations in 3 GeV Au+Au collisions at STAR