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...
| Autores: | , , , , , , , , , , , , , |
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| Formato: | artículo |
| Fecha de publicación: | 2009 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/20646 |
| Acesso em linha: | http://hdl.handle.net/10261/20646 |
| Access Level: | acceso abierto |
| Palavra-chave: | Kaon Physics Lattice QCD Heavy Quarks Physics |
| Resumo: | 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 simeq 0.10 fm, 0.09 fm and 0.07 fm, with pion masses down to mπ simeq 270 MeV. Our results for the light meson decay constants are fK = 158.1(2.4) MeV and fK/fπ = 1.210(18). From the latter ratio, by using the experimental determination of Γ(K → μbar nuμ(γ))/Γ(π → μbar nuμ(γ)) 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 σ level. |
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