Magnetic dipole moments as probes of doubly-bottom molecular pentaquarks

Abstract

We investigate the magnetic dipole moments of doubly-bottom pentaquark states with spin-parities $J^P={\frac{1}{2}}^{-}$ and ${\frac{3}{2}}^{-}$, interpreted as hadronic molecules in the $B{\Sigma }_b$, $B{\Sigma }_b^{\ast }$, and $B^{\ast }{\Sigma }_b$ configurations. The analysis is performed within the framework of QCD light-cone sum rules employing photon distribution amplitudes. Our results demonstrate a strong sensitivity of the magnetic dipole moments to the internal spin structure and quark composition of the states. In particular, the light-quark sector provides the dominant contribution in the $B{\Sigma }_b$ configuration, while the magnetic moment of $B{\Sigma }_b^{\ast }$ is largely governed by the heavy bottom quark. For the $B^{\ast }{\Sigma }_b$ molecular state, both light and heavy sectors contribute constructively, leading to a significantly enhanced magnetic dipole moment. These findings indicate that magnetic dipole moments constitute a sensitive probe of the internal structure of molecular-type doubly-bottom pentaquarks and provide testable predictions for future experimental studies.

Comments: 39 pages, 3 Tables, 2 figures. To be published in Chinese Physics C