Nonresonant explanation for the Y(4260) structure observed in the $e^{+}{e}^{-}\to J/\psi {\pi }^{+}{\pi }^{-}$ process

Abstract

In this work, we proposed a nonresonant explanation for the Y(4260) structure observed in the $e^{+}{e}^{-}\to J/\psi {\pi }^{+}{\pi }^{-}$ process, i.e., Y(4260) is not a genuine resonance. Our result indicates that the Y(4260) structure can be reproduced by the interference of production amplitudes of the $e^{+}{e}^{-}\to J/\psi {\pi }^{+}{\pi }^{-}$ processes via direct $e^{+}{e}^{-}$ annihilation and through intermediate charmonia $\psi (4160)/\psi (4415)$. Besides describing Y(4260) line shape in $e^{+}{e}^{-}\to J/\psi {\pi }^{+}{\pi }^{-}$ well, such a nonresonant explanation for the Y(4260) structure naturally answers why there is no evidence of Y(4260) in the exclusive open-charm decay channel and $R$-value scan.

Comments: 7 pages, 4 figures, 4 tables. Final version accepted for publication in Physical Review D