Mixing angle and decay constants of JP=1+ heavy-light mesons

The mass spectra, mixing angle, and decay constants of the J(P) = 1(+) heavy-light mesons are systematically studied within the framework of the Bethe-Salpeter equation (BSE). The full 1(+) Salpeter wave function is given for the first time. The mixing between the 1(+ -) and 1(++) in the 1(+) heavy-light systems are automatically determined by the dynamics in the equation without any man-made mixing. The results indicate that in a rigorous study there exists the phenomenon of mixing angle inversion or mass inversion within 1(+) heavy-light doublet, which is sensitive to the s-quark mass for the charmed mesons and u- or d-quark masses for the bottomed mesons. This inversion phenomenon can answer the question of why we have confused mixing angles in the literature and partly explain the lower mass of D-s1(2460) compared to that of D-s1(2536). The decay constants are also presented and can behave as a good quantity to distinguish the 1(+) doublet in heavy-light mesons. This study indicates that the light-quark mass may play an important role in deciding the mass order, mixing angle, and decay constant relation between the vertical bar j(l )= 3/2 > and vertical bar j(l) = 1/2 > heavy-light mesons.