A search for $B_{s0}^{\ast }$ and $B_{s1}^{\ast }$ through the $K^{-}p$ interaction

Abstract

Studying heavy-quark hadrons is crucial due to the nonperturbative nature of low-energy QCD, with Heavy-Quark Symmetry (HQS) serving as a key framework for understanding their spin and flavor symmetries. However, a key issue is that the theoretically expected $B^{(\ast )}\bar{K}$ molecular states have not yet been observed, although they are considered the bottom-quark counterparts of the observed ${\bar{D}}^{(\ast )}\bar{K}$ molecular states (corresponding to $D_{s0}(2317/2460{)}^{-}$), which challenges the universality of HQS. The main goal of this work is to search for the theoretically predicted $B\bar{K}$ and $B^{\ast }\bar{K}$ molecular states, namely $B_{s0}^{\ast }(5725)$ and $B_{s1}^{\ast }(5778)$, via the reactions $K^{-}p\to {\Lambda }_b^0{B}_{s0}^{\ast }$ and $K^{-}p\to {\Lambda }_b^0{B}_{s1}^{\ast }$. Within an effective Lagrangian framework, we compute the relevant cross sections, considering $t$-channel $B^{(\ast )}$ exchanges and $K^{-}p$ initial-state interactions (ISI). The results show that the production cross sections of $B_{s0}^{\ast }(5725)$ and $B_{s1}^{\ast }(5778)$ can reach the order of 0.01~nb, and we suggest that experiments searching for $B_{s0}^{\ast }(5725)$ are best performed at $P_{K^{-}}=12.18\mathrm{GeV}$, while higher energies are most favorable for producing $B_{s1}^{\ast }(5778)$. The ISI play a crucial role, as they not only significantly enhance the production cross sections of $B_{s0}^{\ast }(5725)$ and $B_{s1}^{\ast }(5778)$ (by roughly one order of magnitude) but also markedly affect the angular distributions of the produced particles. We also calculated the production cross sections of the conventional quark-antiquark states $B_{s0}^{\ast }(5700)$ and $B_{s1}^{\ast }(5720)$, which are found to be nearly the same as those of $B_{s0}^{\ast }(5725)$ and $B_{s1}^{\ast }(5778)$. Although their internal structures remain ambiguous, these results can inform future experimental searches at CERN and J-PARC.

Comments: 9 pages, 9 figures, 2 table