Improved measurement of the pseudoscalar decay constant fDs

Pseudoscalar decay constants of kaon and D - mesons from N f = 2 twisted mass Lattice QCD

We present the results of a lattice QCD calculation of the pseudoscalar meson decay constants fπ, fK , fD and fDs , performed with Nf = 2 dynamical fermions. The simulation is carried out with the tree-level improved Symanzik gauge action and with the twisted mass fermionic action at maximal twist. We have considered for the final analysis three values of the lattice spacing, a ≃ 0.10 fm, 0.09 ...

Decay Constants of B and D Mesons from Non-perturbatively Improved Lattice QCD

The decay constants of B and D mesons are computed in quenched lattice QCD at two different values of the coupling. The action and operators are O(a) improved with non-perturbative coefficients where available. The results are fB = 218 +5 −5 + 5 −41 MeV, fD = 220 +3 −3 + 2 −24 MeV, fBs = 242 +4 −4 +13 −48 MeV, fDs = 241 +2 −2 + 7 −30 MeV. Systematic errors are discussed in detail. Results for v...

Measurement of D + S → ℓ+ Ν and the Decay Constant Fds

Absolute determination of Ds branching ratios and fDs extraction at a neutrino factory

A method for a direct measurement of the exclusive Ds branching ratios and of the decay constant fDs with a systematical error better than 5% is presented. The approach is based on the peculiar vertex topology of the anti-neutrino induced diffractive charm events. The statistical accuracy achievable with a neutrino factory is estimated.

Measurement of the Pseudoscalar Decay Constant