Production of $Y(4260)$ as a hadronic molecule state of $\barDD_1 +c.c.$ in $e^+e^-$ annihilations

摘要: We investigate the Y(4260) production in e+e− annihilations and probe its structure as the D¯D1+c.c. hadronic molecule state. By introducing a compact cc¯ component into the wavefunction in addition to the long-ranged molecular one, we show that the compositeness relation can still provide a reasonable constraint on the wavefunction renormalization parameter. This study confirms the earlier work that the Y(4260) contains predominantly a D¯D1+c.c. molecular component, and its decays into the D¯D∗π+c.c. channel should have a nontrivial lineshape. It provides a natural explanation for the production of Y(4260) in e+e− annihilations in the same framework. It also allows us to predict the Y(4260) leptonic decay width of which the upper limit is about 500 eV.