Dynamical generation of strange molecular states via vector meson exchange

Abstract We perform a systematic investigation of the interactions between heavy-strange and fully-heavy mesons, specifically the $$B_s^{(*)} D_s^{(*)}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mmultiscripts> <mml:mi>B</mml:mi> <mml:mi>s</mml:mi> <mml:mrow> <mml:mo>(</mml:mo> <mml:mrow/> <mml:mo>∗</mml:mo> <mml:mo>)</mml:mo> </mml:mrow> </mml:mmultiscripts> <mml:mmultiscripts> <mml:mi>D</mml:mi> <mml:mi>s</mml:mi> <mml:mrow> <mml:mo>(</mml:mo> <mml:mrow/> <mml:mo>∗</mml:mo> <mml:mo>)</mml:mo> </mml:mrow> </mml:mmultiscripts> </mml:mrow> </mml:math> , $$B_s^{(*)} B_c^{(*)}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mmultiscripts> <mml:mi>B</mml:mi> <mml:mi>s</mml:mi> <mml:mrow> <mml:mo>(</mml:mo> <mml:mrow/> <mml:mo>∗</mml:mo> <mml:mo>)</mml:mo> </mml:mrow> </mml:mmultiscripts> <mml:mmultiscripts> <mml:mi>B</mml:mi> <mml:mi>c</mml:mi> <mml:mrow> <mml:mo>(</mml:mo> <mml:mrow/> <mml:mo>∗</mml:mo> <mml:mo>)</mml:mo> </mml:mrow> </mml:mmultiscripts> </mml:mrow> </mml:math> , and $$D_s^{(*)} B_c^{(*)}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mmultiscripts> <mml:mi>D</mml:mi> <mml:mi>s</mml:mi> <mml:mrow> <mml:mo>(</mml:mo> <mml:mrow/> <mml:mo>∗</mml:mo> <mml:mo>)</mml:mo> </mml:mrow> </mml:mmultiscripts> <mml:mmultiscripts> <mml:mi>B</mml:mi> <mml:mi>c</mml:mi> <mml:mrow> <mml:mo>(</mml:mo> <mml:mrow/> <mml:mo>∗</mml:mo> <mml:mo>)</mml:mo> </mml:mrow> </mml:mmultiscripts> </mml:mrow> </mml:math> systems, to search for possible hadronic molecular states. By employing the coupled-channel unitary approach within the extended local hidden gauge formalism, we evaluate the interaction potentials driven by the exchange of vector mesons. The Bethe–Salpeter equation with the on-shell approximation is solved to search for poles in the complex energy plane across the pseudoscalar–pseudoscalar ( PP ), pseudoscalar–vector ( PV ), and vector–vector ( VV ) sectors. We account for anomalous parity constraints in the PV sector and spin-dependent contact interactions in the VV sector. Our analysis reveals several dynamically generated bound states and resonances. The robustness of these predictions is confirmed through a systematic scan of the regularization cutoff, revealing monotonic pole trajectories. We extract their pole positions, decay widths, binding energies, coupling constants, scattering lengths, effective ranges, and molecular probabilities. Furthermore, we characterize the spatial extent of the generated states relative to their constituents to qualify the hadronic molecular interpretation. The predicted states serve as excellent candidates for strange exotic hadrons to be searched for in future experiments.