Precise measurements of semileptonic kaon decay rates at KLOE provide the measurement of the CKM mixing matrix element Vus and information about lepton universality. Leptonic kaon decays provide an independent measurement of |Vus|2/|Vud|2, through the ratio Γ(K → μν)/Γ(π → μν). These measurements, together with the result of |Vud| from nuclear β transitions, provide the most precise test of CKM unitarity, allowing the universality of lepton and quark weak couplings to be tested. Bounds on new physics extensions of the standard model with lepton flavor violation can be set using the final KLOE result on RK = Γ(Ke2)/Γ(K m2) = 2.493 ± 0.025stat ± 0.019 syst, based on the measurement of the differential width dΓ(K → enγ)/dEγ/Γ(K → μν) for photon energies 10<Eγ<250 MeV.
Vus and lepton universality from kaon decays at KLOE
Martini M;Meola S;
2009-01-01
Abstract
Precise measurements of semileptonic kaon decay rates at KLOE provide the measurement of the CKM mixing matrix element Vus and information about lepton universality. Leptonic kaon decays provide an independent measurement of |Vus|2/|Vud|2, through the ratio Γ(K → μν)/Γ(π → μν). These measurements, together with the result of |Vud| from nuclear β transitions, provide the most precise test of CKM unitarity, allowing the universality of lepton and quark weak couplings to be tested. Bounds on new physics extensions of the standard model with lepton flavor violation can be set using the final KLOE result on RK = Γ(Ke2)/Γ(K m2) = 2.493 ± 0.025stat ± 0.019 syst, based on the measurement of the differential width dΓ(K → enγ)/dEγ/Γ(K → μν) for photon energies 10I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
