We present evidence for the exclusive reaction e+e- '<Ds±<Ds"<, observed with the Mark III detector at the SLAC storage ring SPEAR. The Ds±< is reconstructed in the ±< decay mode, while the Ds"< is detected as a narrow peak in the recoil-mass distribution. The mass of the Ds* is found to be 2109.3±<2. 1±<3.1 MeV/c2, yielding a Ds*-Ds mass difference of 137.9±<2.1±<4.3 MeV/c2. The width of the Ds* is <22 MeV/c2 at the 90%-confidence level. The observed signal corresponds <(e+e-'<Ds+Ds*-+Ds-Ds*+)B(Ds+'<+)=30±<6± <11 pb at s=4.14 GeV.
ASJC Scopus subject areas
- Physics and Astronomy(all)