Measurements of branching fractions of leptonic and hadronic D-s(+) meson decays and extraction of the D-s(+) meson decay constant

초록

We present measurements of absolute branching fractions of hadronic and leptonic D-s(+) decays to K-K+pi(+), ($)overbar(0)($) over bar (+), eta pi(+), mu(+)nu(mu) and tau(+)nu(tau) and report a search for the leptonic D-s(+) -> e(+) nu(e) decays. The results are obtained from a data sample of 913 fb(-1) collected at or near the gamma (4S) and gamma (5S) resonances with the Belle detector at the KEKB asymmetric- energy e(+)e(-) collider. The branching fractions of hadronic decays are measured to be B(D-s(+) -> K-K+pi(+)) = (5.06 +/- 0: 15 +/- 0.21)%, B(D-s(+) -> ($)overbar(0)($) over bar (+)) = (2.95 +/- 0.11 +/- 0.09)%, B(D-s(+) -> eta pi(+)) = (1.82 +/- 0.14 +/- 0.07)%, where the fi rst and second uncertainties are statistical and systematic, respectively. The branching fractions of leptonic decays are measured to be B(D-s(+) -> mu(+)nu(mu)) = (0.531 +/- 0.028 +/- 0.020)%, B(D-s(+) -> tau(+)nu(tau)) = (5.70 +/- 0.21(-0.30)(+0.31))%, which are combined to determine the D-s(+) meson decay constant fD(s) = (255.5 +/- 4.2 +/- 5.1) MeV. We find no significant signal for D-s(+) -> e(+)nu(e) decays and set an upper limit of B(D-s(+) -> e(+)nu(e)) < 1.0(0.83) +/- 10(-4) at 95% (90%) con fi dence level.

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