Vus from pi and K decay constants in full lattice QCD with physical u, d, s and c quarks
| Autor: | Dowdall, R. J., Davies, C. T. H., Lepage, G. P., McNeile, C. |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | Phys. Rev. D 88, 074504 (2013) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.88.074504 |
| Popis: | We determine the decay constants of the pi and K mesons on gluon field configurations from the MILC collaboration including u, d, s and c quarks. We use three values of the lattice spacing and u/d quark masses going down to the physical value. We use the w_0 parameter to fix the relative lattice spacing and f_pi to fix the overall scale. This allows us to obtain a value for f{K^+}/f{pi^+} = 1.1916(21). Comparing to the ratio of experimental leptonic decay rates gives |Vus| = 0.22564(28){Br(K^+)}(20){EM}(40){latt}(5){Vud} and the test of unitarity of the first row of the Cabibbo-Kobayashi-Maskawa matrix: |Vud|^2+|Vus|^2+|Vub|^2 - 1 = 0.00009(51). Comment: 9 pages, 5 figures. Updated to include more discussion of different checks of our fitting procedures and error analysis. Added a figure on autocorrelations. Published version |
| Databáze: | arXiv |
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