Nuclear Theory·nucl-th

Thursday·August 4, 2022

9 papers—5 primary·4 cross-listed

06
The splitting of directed flow for identified light hadrons ( $K$ and $p$ ) and strange baryons ( $Ξ$ and $Ω$ ) in Au+Au collisions at STAR
Ashik Ikbal Sheikh (for the STAR Collaboration)🇺🇸
The first measurements for rapidity-odd directed flow of $Ξ$ and $Ω$ in Au+Au collisions at $s_{NN} =$ 27 and 200 GeV are reported. The coalescence sum rule is examined with various combinations of hadrons where all constituent quarks are produced, such as $K^{^{-}} (u ˉ s)$ , $p ˉ (u ˉ u ˉ d ˉ)$ , $Λ ˉ (u ˉ d ˉ s ˉ)$ , $ϕ (s s ˉ)$ , $Ξ ˉ^{+} (d ˉ s ˉ s ˉ)$ , $Ω^{-} (sss)$ , and $Ω ˉ^{+} (s ˉ s ˉ s ˉ)$ . For such combinations, a systematic violation of the sum rule is observed with increasing difference in the electric charge and the strangeness content of the combinations. Measurements are compared with the calculations of A Multi-Phase Transport (AMPT) model and Parton-Hadron String Dynamics (PHSD) model with electromagnetic (EM) field. The PHSD model with EM field agrees with the measurements within uncertainties.
↳ nucl-exhep-exhep-phnucl-thActa Phys.Polon.Supp.(2023)·1 citation
07
Possible molecular states from interactions of charmed baryons
Dan Song🇨🇳 · Lin-Qing Song🇨🇳 · Shu-Yi Kong🇨🇳 · Jun He🇨🇳
In this work, we perform a systematic study of possible molecular states composed of two charmed baryons including hidden-charm systems $Λ_{c} Λ ˉ_{c}$ , $Σ_{c}^{(*)} Σ ˉ_{c}^{(*)}$ , and $Λ_{c} Σ ˉ_{c}^{(*)}$ , and corresponding double-charm systems $Λ_{c} Λ_{c}$ , $Σ_{c}^{(*)} Σ_{c}^{(*)}$ , and $Λ_{c} Σ_{c}^{(*)}$ . With the help of the heavy quark chiral effective Lagrangians, the interactions are described with $π$ , $ρ$ , $η$ , $ω$ , $ϕ$ , and $σ$ exchanges. The potential kernels are constructed, and inserted into the quasipotential Bethe-Salpeter equation. The bound states from the interactions considered is studied by searching for the poles of the scattering amplitude. The results suggest that strong attractions exist in both hidden-charm and double-charm systems considered in the current work, and bound states can be produced in most of the systems. More experiment studies about these molecular states are suggested though the nucleon-nucleon collison at LHC and nucleon-antinucleon collison at $P ˉ ANDA$ .
↳ hep-phnucl-thPRD(2022)·11 citations
08
Longitudinal spin polarization of $Λ -$ hyperons in a thermal model
Wojciech Florkowski🇵🇱 · Avdhesh Kumar🇹🇼 · Aleksas Mazeliauskas🇨🇭 · Radoslaw Ryblewski🇵🇱
We briefly review the thermal model predictions related to longitudinal spin polarization of $Λ -$ hyperons emitted from a hot and rotating hadronic medium produced in the non-central relativistic heavy ion collisions.
↳ hep-phnucl-thActa Phys.Polon.Supp.(2023)·0 citations
09
Origin of Plutonium-244 in the Early Solar System
Maria Lugaro · Andrés Yagüe López · Benjámin Soós · Benoit Côté · Mária Pető · Nicole Vassh · Benjamin Wehmeyer · Marco Pignatari
We investigate the origin in the early Solar System of the short-lived radionuclide 244Pu (with a half life of 80 Myr) produced by the rapid (r) neutron-capture process. We consider two large sets of r-process nucleosynthesis models and analyse if the origin of 244Pu in the ESS is consistent with that of the other r and slow (s) neutron-capture process radioactive nuclei. Uncertainties on the r-process models come from both the nuclear physics input and the astrophysical site. The former strongly affects the ratios of isotopes of close mass (129I/127I, 244Pu/238U, and 247Pu/235U). The 129I/247Cm ratio, instead, which involves isotopes of a very different mass, is much more variable than those listed above and is more affected by the physics of the astrophysical site. We consider possible scenarios for the evolution of the abundances of these radioactive nuclei in the galactic interstellar medium and verify under which scenarios and conditions solutions can be found for the origin of 244Pu that are consistent with the origin of the other isotopes. Solutions are generally found for all the possible different regimes controlled by the interval ( $δ$ ) between additions from the source to the parcel of interstellar medium gas that ended up in the Solar System, relative to decay timescales. If r-process ejecta in interstellar medium are mixed within a relatively small area (leading to a long $δ$ ), we derive that the last event that explains the 129I and 247Cm abundances in the early Solar System can also account for the abundance of 244Pu. Due to its longer half life, however, 244Pu may have originated from a few events instead of one only. If r-process ejecta in interstellar medium are mixed within a relatively large area (leading to a short $δ$ ), we derive that the time elapsed from the formation of the molecular cloud to the formation of the Sun was 9-16 Myr.
↳ astro-ph.SRastro-ph.EPastro-ph.GAnucl-thUniverse(2022)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE

The splitting of directed flow for identified light hadrons (K and p) and strange baryons (Ξ and Ω) in Au+Au collisions at STAR

Possible molecular states from interactions of charmed baryons

Longitudinal spin polarization of Λ−hyperons in a thermal model

Origin of Plutonium-244 in the Early Solar System

Affiliations

The splitting of directed flow for identified light hadrons ( $K$ and $p$ ) and strange baryons ( $Ξ$ and $Ω$ ) in Au+Au collisions at STAR

Longitudinal spin polarization of $Λ -$ hyperons in a thermal model