Studies on X(4260) and X(4660) particles

Abstract

Studies on the X(4260) and X(4660) resonant states in an effective lagrangian approach are reviewed. Using a Breit--Wigner propagator to describe their propagation, we find that the X(4260) has a sizable coupling to the $\omega {\chi }_{c0}$ channel, while other couplings are found to be negligible. Besides, it couples much stronger to $\sigma$ than to $f_0(980)$: $|g_{X\Psi \sigma }^2/g_{X\Psi f_0(980)}^2|\sim O(10).$ As an approximate result for X(4660), we obtain that the ratio of $\frac{Br(X\to {\Lambda }_c^{+}{\Lambda }_c^{-})}{Br(X\to \Psi (2s){\pi }^{+}{\pi }^{-})}\simeq 20$. Finally, taking X(3872) as an example, we also point out a possible way to extend the previous method to a more general one in the effective lagrangian approach.

Talk given by H. Q. Zheng at "Xth Quark Confinement and the Hadron Spectrum", October 8-12, 2012, TUM Campus Garching, Munich, Germany. 6 pages, 3 figures, 3 tables