Pseudoscalar decay constants of kaon and D-mesons from Nf=2 twisted mass Lattice QCD - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Article Dans Une Revue Journal of High Energy Physics Année : 2009

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

Résumé

We present the results of a lattice QCD calculation of the pseudoscalar meson decay constants fpi, 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 fm and 0.07 fm, with pion masses down to mpi~270 MeV. Our results for the light meson decay constants are fK=158.1(2.4) MeV and fK/fpi=1.210(18). From the latter ratio, by using the experimental determination of Gamma(K-->mu nu_mu (gamma))/ Gamma(pi--> mu nu_mu (gamma)) and the average value of |Vud| from nuclear beta decays, we obtain |Vus|=0.2222(34), in good agreement with the determination from semileptonic Kl3 decays and the unitarity constraint. For the D and Ds meson decay constants we obtain fD=197(9) MeV, fDs=244(8) MeV and fDs/fD=1.24(3). Our result for fD is in good agreement with the CLEO experimental measurement. For fDs our determination is smaller than the PDG 2008 experimental average but in agreement with a recent improved measurement by CLEO at the 1.4 sigma level.

Dates et versions

hal-00375786 , version 1 (16-04-2009)

Identifiants

Citer

B. Blossier, P. Dimopoulos, R. Frezzotti, B. Haas, G. Herdoiza, et al.. Pseudoscalar decay constants of kaon and D-mesons from Nf=2 twisted mass Lattice QCD. Journal of High Energy Physics, 2009, 0907, pp.043. ⟨10.1088/1126-6708/2009/07/043⟩. ⟨hal-00375786⟩
40 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More