Probing double hadron resonance by complex momentum representation method

Abstract

Resonances are ubiquitous phenomena in nature, and physicists have developed many methods to explore resonant states. Of particular note is the complex momentum representation(CMR) method, which has been developed and widely used in the study of resonant states in atomic, molecular and nuclear physics. Here, for the first time, we have developed this novel method to study hadron resonant states. The CMR method is applied to probe the bound and resonant states for the $\Lambda_cD(\bar{D})$ and $\Lambda_c\Lambda_c(\bar{\Lambda}_c)$ systems, in which the resonant states are exposed clearly in complex momentum plane and the resonance parameters can be determined precisely without imposing unphysical parameters. The results show that the CMR method has achieving higher accuracy than other widely used methods. This method is not only very effective for narrow resonances, but also can be reliably applied to broad resonances.