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HK: Fachverband Physik der Hadronen und Kerne
HK 42: Hadronenstruktur und -spektroskopie VII
HK 42.4: Vortrag
Mittwoch, 23. März 2011, 17:30–17:45, C-2
Light quark mass dependence of the D and Ds decay constants — •Michael Altenbuchinger1, Wolfram Weise1, and Lisheng Geng1,2 — 1Physik Department, Technische Universität München, D-85747 Garching, Germany — 2School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191, China
We study the light quark mass dependence of the D and Ds meson decay constants, fD and fDs, using a covariant formulation of chiral perturbation theory (χPT) at next-to-next-to-leading order (NNLO). Using the HPQCD results for the D(Ds) decay constants as a benchmark we show that covariant χPT can describe the HPQCD results better than heavy meson χPT (HMχPT) at both NLO and NNLO. Within the same framework, taking into account sub-leading (1/mQ, with mQ the heavy quark mass) corrections to the values of the low-energy constants and employing the lattice QCD results for gBB*π, we estimate the ratio of fBs/fB to be 1.22−0.04+0.05, which agrees well with the HPQCD result 1.226(26).
Work supported in part by BMBF, the A.v. Humboldt foundation, GSI and the DFG Excellence Cluster "Origin and Structure of the Universe".