Proposal to detect a moving triangle singularity in $\ddot{I}ˆ(2S)\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}{K}^{+}{K}^{-}$ process

Abstract

In this work, we propose that there exists a moving triangle singularity in the $\ddot{I}ˆ(2S)\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}{K}^{+}{K}^{-}$ process, whose position can vary from 1.158 to 1.181 GeV in the invariant mass spectrum of $K^{+}{K}^{-}$. After a precise analysis on this process, it turns out that after doing some cuts on $m_{\ddot{I}{€}^{+}\ddot{I}{€}^{-}}$, experiments do have the opportunity to observe this triangle singularity. In addition, when changing the cuts on $m_{\ddot{I}{€}^{+}\ddot{I}{€}^{-}}$, the movement of the predicted triangle singularity can also be observed. Thus, we suggest future experiments, especially Super Tau-Charm Facility (STCF), to do an anlysis on the $\ddot{I}ˆ(2S)\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}{K}^{+}{K}^{-}$ process to verify our prediction.