Observation of $\ddot{I}ˆ(4415)\to D\bar{D}{}_2^{\ast }(2460)$ decay using initial-state radiation

Abstract

We report the first observation of the $\ddot{I}ˆ(4415)$ resonance in the reaction $\e^+e^-\to D^0 D^-π^+$ and a measurement of its cross section in the center-of-mass energy range $4.0\mathrm{GeV}$ to $5.0\mathrm{GeV}$ with initial state radiation. From a study of resonant structure in $\ddot{I}ˆ(4415)$ decay we conclude that the $\ddot{I}ˆ(4415)\to D^0{D}^{-}\ddot{I}{€}^{+}$ decay is dominated by $\ddot{I}ˆ(4415)\to D\bar{D}{}_2^{\ast }(2460)$. We obtain $\mathcal{B}(\ddot{I}ˆ(4415)\to D^0{D}^{-}\ddot{I}{€}_{\mathrm{non}-\mathrm{resonant}}^{+})/\mathcal{B}(\ddot{I}ˆ(4415)\to D\bar{D}{}_2^{\ast }(2460)\to D^0{D}^{-}\ddot{I}{€}^{+})<0.22$ at 90% C.L. The analysis is based on a data sample collected with the Belle detector with an integrated luminosity of 673 ${\mathrm{fb}}^{-1}$.

Presented on EPS07, LP07, QWG07conferences