Light quark mass dependence of the D and Ds decay constants

• Published in: Physics letters. B Vol. 696; no. 4; pp. 390 - 395
• Main Authors: Geng, L.S., Altenbuchinger, M., Weise, W.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 07-02-2011; Elsevier
• Subjects: Covariant chiral perturbation theory; Decays of charmed and bottom mesons; Exact sciences and technology; Lattice QCD calculations; Nuclear physics; Physics; The physics of elementary particles and fields; Decays of charmed and bottom mesons; Covariant chiral perturbation theory; Lattice QCD calculations; Perturbation theory; D minus mesons; Lattice theory; Quark mass; Elementary particle mass; Meson decay; D mesons; Heavy quark effective theory; Covariant theory; Corrections
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2010.12.060

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 lattice 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).