Improved covariant analysis of $B_c^{+}\to {\chi }_{c1}(nP)$ decays and implications for the nature of ${\chi }_{c1}(3872)$

Shi-Hang Zhang, Jia-Yi Zheng, Wei Li +5

We study the weak decays $B_c^{+}\to {\chi }_{c1}(nP){\ell }^{+}{\nu }_{\ell }$ and $B_c^{+}\to {\chi }_{c1}(nP)X$ (n=1,2,3) within the Bethe-Salpeter formalism, treating ${\chi }_{c1}(3872)$ as the conventional $χ…