We present the first lattice QCD estimate of the form factor f+(0), which is the key theoretical ingredient to extract Vus from Kℓ3 decays. Our result, f+K0π-(0) = 0.960 ± 0.005stat ± 0.007syst, is in good agreement with the model estimate by Leutwyler and Roos and with the recent QCD sum rule estimate. After combining recent experimental results with our value for f+K0π- (0), we could verify the unitarity of the first row of the CKM matrix, namely Vus 2 + Vud 2 + Vub 2 = 0.9997 (14). To make our estimate fully model independent we need to remove the quenched approximation and use ever lower quark masses (keeping, however, finite volume effects under control). © 2004 Elsevier B.V. All rights reserved.
The K ---> pi vector form factor at zero momentum transfer on the lattice / D., Becirevic; Martinelli, Guido; Spqr, Collaboration. - In: NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS. - ISSN 0920-5632. - 140:(2005), pp. 387-389. (Intervento presentato al convegno Lattice 2004 tenutosi a Batavia; United Staes) [10.1016/j.nuclphysbps.2004.11.247].
The K ---> pi vector form factor at zero momentum transfer on the lattice
MARTINELLI, Guido;
2005
Abstract
We present the first lattice QCD estimate of the form factor f+(0), which is the key theoretical ingredient to extract Vus from Kℓ3 decays. Our result, f+K0π-(0) = 0.960 ± 0.005stat ± 0.007syst, is in good agreement with the model estimate by Leutwyler and Roos and with the recent QCD sum rule estimate. After combining recent experimental results with our value for f+K0π- (0), we could verify the unitarity of the first row of the CKM matrix, namely Vus 2 + Vud 2 + Vub 2 = 0.9997 (14). To make our estimate fully model independent we need to remove the quenched approximation and use ever lower quark masses (keeping, however, finite volume effects under control). © 2004 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
