Author/Authors :
OPAL Collaboration، نويسنده , , K Ackerstaff، نويسنده , , G Alexander، نويسنده , , J Allison، نويسنده , , N. Altekamp، نويسنده , , K.J. Anderson، نويسنده , , S Anderson، نويسنده , , S Arcelli، نويسنده , , S Asai، نويسنده , , S.F Ashby، نويسنده , , D Axen، نويسنده , , G Azuelos، نويسنده , , A.H. Ball، نويسنده , , E Barberio، نويسنده , , R.J. Barlow، نويسنده , , R. Bartoldus، نويسنده , , J.R. Batley، نويسنده , , S Baumann، نويسنده , , J Bechtluft، نويسنده , , C Beeston، نويسنده , , et al.، نويسنده ,
Abstract :
A search for decays of the Bc meson was performed using data collected from 1990–1995 with the OPAL detector on or near the Z0 peak at LEP. The decay channels Bc+→J/ψπ+, Bc+→J/ψa1+ and Bc+→J/ψℓ+ν were investigated, where ℓ denotes an electron or a muon. Two candidates are observed in the mode Bc+→J/ψπ+, with an estimated background of (0.63±0.20) events. The weighted mean of the masses of the two candidates is (6.32±0.06) GeV/c2, which is consistent with the predicted mass of the Bc meson. One candidate event is observed in the mode Bc+→J/ψℓ+ν, with an estimated background of (0.82±0.19) events. No candidate events are observed in the Bc+→J/ψa1+ decay mode, with an estimated background of (1.10±0.22) events. Upper bounds at the 90% confidence level are set on the production rates for these processes.
