Possible hidden-bottom molecular pentaquarks from $P$-wave $\Lambda_bB^{(*)}/\Sigma_b^{(*)}B^{(*)}$ interactions

Abstract

In this work, we perform a systematic investigation of the hidden-bottom molecular pentaquark states, encompassing both bound states and resonances, which originate from the $P$-wave interactions between ground-state bottom baryons ($\Lambda_b$, $\Sigma_b^{(*)}$) and ground-state antibottom mesons ($B^{(*)}$). Adopting the one-boson-exchange model and including the coupled-channel effects, we derive the effective potentials for all allowed quantum numbers $I(J^P) = 1/2(1/2^+)$, $1/2(3/2^+)$, $1/2(5/2^+)$, $1/2(7/2^+)$, $3/2(1/2^+)$, $3/2(3/2^+)$, $3/2(5/2^+)$, and $3/2(7/2^+)$. We then solve the coupled-channel Schr\"odinger equations to search for the bound-state solutions and perform the phase-shift analyses to identify resonance poles. Our results reveal a rich spectrum of positive-parity hidden-bottom molecular pentaquark candidates. In the isospin $I=1/2$ sector, we find several loosely bound states and associated resonances, particularly in the $\Sigma_b B^*$ and $\Sigma_b^* B^*$ channels, where the coupled-channel dynamics plays an essential role in their formation. In the isospin $I=3/2$ sector, the attraction is generally weaker because of the isospin factors. Nevertheless, we still obtain the loosely bound states and resonances, such as the $\Sigma_b^* B^*$ states with $J^P=3/2^+$, $5/2^+$, and $7/2^+$. The prominence of high-spin partial waves, for instance the $^6P_J$ components, underscores the importance of the spin-spin and tensor interactions. Our predictions provide a comprehensive and systematic spectrum of the $P$-wave hidden-bottom molecular pentaquark states and offer clear guidance for future experimental searches at LHCb and Belle~II.