Exploring the $P$-wave bottom-strange molecular pentaquarks with the complex scaling method

Abstract

In this work, we perform a systematic investigation of the $P$-wave ${\Sigma }_{b}K/{\Lambda }_b{K}^{\ast }/{\Sigma }_b{K}^{\ast }$ and ${\Sigma }_b\bar{K}/{\Lambda }_b{\bar{K}}^{\ast }/{\Sigma }_b{\bar{K}}^{\ast }$ systems for all possible $I(J^P)$ combinations. In contrast to our earlier study of the negative-parity sector [Eur. Phys. J. C \textbf{85}, 1026 (2025)], the positive-parity sector is dominated by resonances. For the coupled-channel $I(J^P)=1/2(1/2^{+})$ ${\Sigma }_{b}K/{\Lambda }_b{K}^{\ast }/{\Sigma }_b{K}^{\ast }$ system, we predict a narrow resonance above the ${\Sigma }_{b}K$ threshold. In the $I(J^P)=1/2(3/2^{+})$ ${\Lambda }_b{K}^{\ast }/{\Sigma }_b{K}^{\ast }$ system, a molecular resonance candidate is found above the ${\Lambda }_b{K}^{\ast }$ threshold. For the higher-isospin $I=3/2$ sector, resonances are identified in the ${\Sigma }_b{K}^{\ast }$ subsystem for both $J^P=1/2^{+}$ and $3/2^{+}$ cases, though both states exhibit relatively compact sizes. We also extend our analysis to the ${\Sigma }_b\bar{K}/{\Lambda }_b{\bar{K}}^{\ast }/{\Sigma }_b{\bar{K}}^{\ast }$ systems, where a cutoff-sensitive resonance is found in the $I(J^P)=1/2(1/2^{+})$ configuration. A broad molecular resonance candidate is found below the ${\Sigma }_b{\bar{K}}^{\ast }$ threshold in the $I(J^P)=1/2(3/2^{+})$ system. We hope that these predictions provide useful guidance for future experimental searches for bottom-strange molecular pentaquarks by LHCb.

Comments: 14 pages, 5 figures