Precise measurement of Γ ( K → eν ( γ ) ) / Γ ( K → μ ν ( γ ) ) and study of K →
نویسندگان
چکیده
We present a precise measurement of the ratio RK = Γ(K → eν(γ))/Γ(K → μν(γ)) and a study of the radiative process K → eνγ, performed with the KLOE detector. The results are based on data collected at the Frascati ee collider DAΦNE for an integrated luminosity of 2.2 fb. We find RK = (2.493 ± 0.025stat ± 0.019syst) × 10 , in agreement with the Standard Model expectation. This result is used to improve constraints on parameters of the Minimal Supersymmetric Standard Model with lepton flavor violation. We also measured the differential decay rate dΓ(K → eνγ)/dEγ for photon energies 10 < Eγ < 250 MeV. Results are compared with predictions from theory. PACS. 13.20.Eb Decays of K mesons
منابع مشابه
Improved Measurement of the π→eν Branching Ratio.
A new measurement of the branching ratio R_{e/μ}=Γ(π^{+}→e^{+}ν+π^{+}→e^{+}νγ)/Γ(π^{+}→μ^{+}ν+π^{+}→μ^{+}νγ) resulted in R_{e/μ}^{exp}=[1.2344±0.0023(stat)±0.0019(syst)]×10^{-4}. This is in agreement with the standard model prediction and improves the test of electron-muon universality to the level of 0.1%.
متن کامل0 Se p 20 05 Measurement of the Absolute Branching Ratio for the K + → μ + ν ( γ ) Decay with the KLOE Detector
We have measured the fully inclusive K+ → μ+ν(γ) absolute branching ratio with the KLOE experiment at DAΦNE, the Frascati φ–factory. From some 865,283 K+ → μ+ν(γ) decays obtained from a sample of ∼5.2 × 108 φ-meson decays, we find BR(K+ → μνμ(γ))=0.6366±0.0009stat.±0.0015syst., corresponding to an overall fractional error of 0.27%. Using recent lattice results on the decay constants of pseudosc...
متن کاملO ct 2 00 5 Measurement of the Absolute Branching Ratio for the K + → μ + ν ( γ ) Decay with the KLOE Detector
We have measured the fully inclusive K+ → μ+ν(γ) absolute branching ratio with the KLOE experiment at DAΦNE, the Frascati φ–factory. From some 865,283 K+ → μ+ν(γ) decays obtained from a sample of ∼5.2 × 108 φ-meson decays, we find BR(K+ → μνμ(γ))=0.6366±0.0009stat.±0.0015syst., corresponding to an overall fractional error of 0.27%. Using recent lattice results on the decay constants of pseudosc...
متن کاملHadronic mass spectrum analysis of D + → K − π + µ + ν decay and measurement
We present a Kπ mass spectrum analysis of the four-body semileptonic charm decay D+ → K−π+μ+ν in the range of 0.65 GeV/c2 < mKπ < 1.5 GeV/c 2. We observe a non-resonant contribution of 5.30 ± 0.74 − 0.96% with respect to the total D+ → K−π+μ+ν decay. For the K∗(892)0 resonance, we obtain a mass of 895.41 ± 0.32 − 0.43 MeV/c 2, a width of 47.79 ± 0.86 − 1.06 MeV/c 2, and a BlattWeisskopf damping...
متن کاملLepton Flavor violation searches with kaons at NA62
The ratio RK = Γ(K ± → e±ν)/Γ(K± → μ±ν) between the two leptonic decay rates of charged kaons is precisely predicted within the Standard Model (SM). A recent theoretical work noticed that SUSY extensions of the SM can induce mu-electron universality violation in such a way to introduce a shift of the RK value up to few percent respect to SM prediction. Presently the experimental relative error ...
متن کامل