Properties of the tensor state bcb¯c¯

Abstract

Spectroscopic parameters and decays of the exotic tensor meson T with content bcb¯c¯ are explored in the context of the diquark-antidiquark model. We treat it as a state built of axial-vector diquark bTCγμc and antidiquark b¯γνCc¯T, where C is the charge conjugation matrix. The mass m and current coupling Λ of this tetraquark are extracted from two-point sum rules. Our result for m=(12.70±0.09)  GeV proves that T is unstable against strong dissociations to two-meson final states. Its dominant decay channels are processes T→J/ψϒ, ηbηc, and Bc(*)+Bc(*)−. Kinematically allowed transformations of T include also decays T→D(*)+D(*)− and D(*)0D¯(*)0, which are generated by bb¯ annihilation inside of T. The full width of T is estimated by considering all of these channels. Their partial widths are calculated by invoking methods of three-point sum rule approach, which are required to evaluate strong couplings at corresponding tetraquark-meson-meson vertices. Our predictions for the mass and width ΓT=(117.4±15.9)  MeV of the tensor state T provide useful information for experimental studies of fully heavy four-quark exotic structures. Published by the American Physical Society 2025