Decays of charmed hadrons at belle

Abstract

Using e+e− annihilation data recorded by the Belle detector, we obtain preliminary branching fraction B(D+s → μ +νμ) = (6.44 ± 0.76 ± 0.52) · 10-3, implying a D+s decay constant of fDs = 275 ± 16 ± 12 MeV. The D+s is tagged in the events e+e− → D*+sDKX, D*+s → D+sγ, by full reconstruction of the DKXγ system, where X denotes additional pions or photon from fragmentation. We observe for the first time the decay Ds1(2536)+ → K+ with the ratio of branching fractions π = (3.27 ± 0.18 ± 0.37)%. We also study the angular distributions in the Ds1(2536)+ → D*+K0s decay and measure the ratio of D- and S-wave amplitudes. The S-wave dominates, with a partial width of Γs/Γtotal = 0.72 ± 0.05 ± 0.01.