Nonresonant explanation for the Y(4260) structure observed in the $e^+e^-\to J/ψπ^+π^-$ process

Abstract

In this work, we proposed a nonresonant explanation for the Y(4260) structure observed in the $e^+e^-\to J/ψπ^+π^-$ 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 $e^+e^-\to J/ψπ^+π^-$ processes via direct $e^+e^-$ annihilation and through intermediate charmonia $ψ(4160)/ψ(4415)$. Besides describing Y(4260) line shape in $e^+e^-\to J/ψπ^+π^-$ 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.

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