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 $J^P=\tfrac{1}{2}^-$ and $\tfrac{3}{2}^-$, interpreted as hadronic molecules in the $B\Sigma_b$, $B\Sigma_b^{*}$, and $B^{*}\Sigma_b$ 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 $B\Sigma_b^{*}$ is largely governed by the heavy bottom quark. For the $B^{*}\Sigma_b$ 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.