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

TL;DR

This paper reviews the properties of X(4260) and X(4660) particles using an effective Lagrangian approach, highlighting their couplings and decay ratios, and suggests extending the method to other states like X(3872).

Contribution

It provides a detailed analysis of the couplings and decay channels of X(4260) and X(4660) within an effective Lagrangian framework, and proposes a method extension to other resonant states.

Findings

X(4260) couples strongly to ωχ_{c0} channel.

X(4260) couples more strongly to σ than to f_0(980).

The decay ratio Br(X→Λ_c^+Λ_c^-)/Br(X→Ψ(2s)π^+π^-) ≈ 20.

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 $f_0(980)$: $|g_{X\Psi \sigma}^2/g^2_{X\Psi f_0(980)}|\sim O(10) \ .$ As an approximate result for X(4660), we obtain that the ratio of $\frac{Br(X\rightarrow\Lambda_c^+\Lambda_c^-)}{Br(X\rightarrow\Psi(2s)\pi^+\pi^-)}\simeq 20$. 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.