The study of $B_c^- \to X(3872)\pi^-(K^-)$ Decays in the Covariant Light-Front Approach

Understand

In the covariant light-front quark model, we calculate the form factors of $B_c^-\to J/\psi$ and $B_c^-\to X(3872)$.

• Since the factorization of the exclusive processes $B_c^- \to J/\psi\pi^-(K^-)$ and $B_c^- \to X(3872)\pi^-(K^-)$ can be proved in the soft-collinear effective theory, we can get the branching ratios for these decays easily from the form factors.
• Taking the uncertainties into account, our results for the branching ratio of $B_c^-\to J/\psi \pi^-(K^-)$ are consistent with the previous studies.
• By identifying X(3872) as a $1^{++}$ charmonium state, we obtain ${\cal BR}(B_c^-\to X(3872)\pi^-)=(1.7^{+0.7+0.1+0.4}_{-0.6-0.2-0.4}) \times 10^{-4}$ and ${\cal BR}(B_c^-\to X(3872)K^-)=(1.3^{+0.5+0.1+0.3}_{-0.5-0.2-0.3})\times 10^{-5}$.