Nuclear Theory·nucl-th

Friday·April 7, 2023

6 papers—3 primary·3 cross-listed

04
[Submitted on 6 Apr 2023] (cross-list from nucl-ex)
Electric-charge-dependent directed flow splitting of produced quarks in Au+Au collisions
STAR Collaboration
We report directed flow ( $v_{1}$ ) of multistrange baryons ( $Ξ$ and $Ω$ ) and improved $v_{1}$ data for $K^{-}$ , $p ˉ$ , $Λ ˉ$ and $ϕ$ in Au+Au collisions at $s_{NN} =$ 27 and 200 GeV from the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). We focus on particles whose constituent quarks are not transported from the incoming nuclei but instead are produced in the collisions. At intermediate impact parameters, we examine quark coalescence behavior for particle combinations with identical quark content, and search for any departure from this behavior (``splitting'') for combinations having non-identical quark content. Under the assumption of quark coalescence for produced quarks, the splitting strength appears to increase with the electric charge difference of the constituent quarks in the combinations, consistent with electromagnetic effect expectations.
Comments:
6 pages, 6 figures
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2304.02831 [pdf]
PLB(2025)·12 citations
05
[Submitted on 6 Apr 2023] (cross-list from hep-ph)
Possible molecular dibaryons with $csss q q$ quarks and their baryon-antibaryon partners
Shu-Yi Kong🇨🇳 · Jun-Tao Zhu🇨🇳 · Jun He🇨🇳
In this work, we systematically investigate the charmed-strange dibaryon systems with $csss q q$ quarks and their baryon-antibaryon partners from the interactions $Ξ_{c}^{(^{'}, *)} Ξ^{(*)}$ , $Ω_{c}^{(*)} Λ$ , $Ω_{c}^{(*)} Σ^{(*)}$ , $Λ_{c} Ω$ and $Σ_{c}^{(*)} Ω$ and their baryon-antibaryon partners from interactions $Ξ_{c}^{(^{'}, *)} Ξ ˉ^{(*)}$ , $Ω_{c}^{(*)} Λ ˉ$ , $Ω_{c}^{(*)} Σ ˉ^{(*)}$ , $Λ_{c} Ω ˉ$ and $Σ_{c}^{(*)} Ω ˉ$ . The potential kernels are constructed with the help of effective Lagrangians under SU(3), heavy quark, and chiral symmetries to describe these interactions. To search for possible molecular states, the kernels are inserted into the quasipotential Bethe-Salpeter equation, which is solved to find poles from scattering amplitude. The results suggest that 36 and 24 bound states can be found in the baryon-baryon and baryon-antibaryon interactions, respectively. However, much large values of parameter $α$ are required to produce the bound states from the baryon-antibaryon interactions, which questions the existence of these bound states. Possible coupled-channel effect are considered in the current work to estimate the couplings of the molecular states to the channels considered.
Comments:
13 pages, 5 figures. arXiv admin note: text overlap with arXiv:2208.11962
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2304.02920 [pdf]
EPJC(2023)·7 citations
06
[Submitted on 6 Apr 2023] (cross-list from hep-ph)
B meson production in Pb+Pb at 5.02 ATeV at LHC: estimating the diffusion coefficient in the infinite mass limit
Maria Lucia Sambataro (1 and 2)🇮🇹 · Vincenzo Minissale (2)🇮🇹 · Salvatore Plumari (1 and 2)🇮🇹 · Vincenzo Greco (1 and 2) ((1) Department of Physics and Astronomy 'E. Majorana', University of Catania, Via S. Sofia 64, 1-95123 Catania, Italy, (2) Laboratori Nazionali del Sud, INFN-LNS, Via S. Sofia 62, I-95123 Catania, Italy)🇮🇹
In the last decade a Quasi-Particle Model (QPM) has been developed to study charm quark dynamics in ultra-relativistic heavy-ion collisions supplying a satisfactory description of the main observables for $D$ meson and providing an estimate of the space-diffusion coefficient $D_{s} (T)$ from the phenomenology. In this paper, we extend the approach to bottom quarks describing their propagation in the quark-gluon plasma within an event-by-event full Boltzmann transport approach followed by a coalescence plus fragmentation hadronization. We find that QPM approach is able to correctly predict the first available data on $R_{AA} (p_{T})$ and $v_{2} (p_{T})$ of single-electron from B decays without any parameter modification w.r.t. the charm. We show also predictions for centralities where data are not yet available for both $v_{2} (p_{T})$ and $v_{3} (p_{T})$ . Moreover, we discuss the significant breaking of the expected scaling of the thermalization time $τ_{t h}$ with $M_{Q} / T$ , discussing the evolution with mass of $D_{s} (T)$ to better assess the comparison to lQCD calculations. We find that at $T = T_{c}$ charm quark $D_{s} (T)$ is about a factor of 2 larger than the asymptotic value for $M \to \infty$ , while bottom $D_{s} (T)$ is only a $20 - 25%$ higher. This implies a $D_{s} (T)$ which is consistent within the current uncertainty to the most recent lattice QCD calculations with dynamical quarks for $M \to \infty$ .
Comments:
8 pages, 5 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2304.02953 [pdf]
PLB(2024)·35 citations

Affiliations

first authorsco-authorsvia INSPIRE

Electric-charge-dependent directed flow splitting of produced quarks in Au+Au collisions

Possible molecular dibaryons with csssqq quarks and their baryon-antibaryon partners

B meson production in Pb+Pb at 5.02 ATeV at LHC: estimating the diffusion coefficient in the infinite mass limit

Affiliations

Possible molecular dibaryons with $csss q q$ quarks and their baryon-antibaryon partners