1 Decays of the Meson B c to a P − Wave Charmonium State χ c or h c

The semileptonic decays Bc−→χc + l + νl and the two body nonleptonic decays Bc−→χc + h (here h indicates a meson) are computed. Three interesting matters are pointed out: 1). At the ‘leading order’, all the form factors appearing in the weak-current matrix elements between Bc and χc or hc can be formulated in terms of two independent overlap-integrals of the wave functions of the Bc and the one of χc (or hc) with suitable kinetic factors inserted. 2). The decays are sizable that they may be accessible in Run-II of Tevatron and in LHC in the near future, especially when the detectors BTeV and LHCB are concerned. 3). The cascade decays, Bc → χc(P1,2) + l + νl or the nonleptonic decays Bc → χc(P1,2) + h and a radiative one χc( P1,2) → J/ψ + γ followed, may affect the measurements of the decays Bc → J/ψ + l + νl or Bc → J/ψ + h substantially (the efficiency to detect the photon in the cascade decay cannot not be so ideal). PACS Numbers: 13.20.He, 13.25.Hw, 14.40.Nd, 14.40.Lb, 12.39.Jh 1