Study of theK+Decay

Abstract

Some properties of the various decay modes of K+ mesons have been studied with hodoscope scintillation counters. 122 Kμ3 events were identified in the high-energy end of the muon energy spectrum from 115±3 MeV to 134 MeV which yielded (0.42±0.10)% as the relative branching ratio. The result, together with the Ke3 branching ratio and the low-energy end of the Kμ3 muon energy spectrum, is found to satisfy a constant form factor V−A interaction. The muon longitudinal polarization for the Kμ3 events was found to be +0.8−0.8+0.2 which is two standard deviations from the calculated value -0.81 using the constant form factors which best fit the spectrum. A lifetime analysis of the decay modes gave T(Kμ3)=(1.06±0.16)×18−8 sec, T(Kπ2)=(1.197±0.032)×10−8 sec, and T(Kμ2)=(1.259±0.018)×10−8 sec which are consistent with a single total lifetime, as expected. The total lifetime was found to be T(K+)=(1.231±0.011)×10−8 sec in agreement with previous values. The relative Kμ2Kπ2 branching ratio was measured as 2.98±0.25. A search for the occurrence of an intermediate-mass lepton in the decay K→χ+ν established 3×10−4 as the upper limit for the branching ratio with me<mχ<75 MeV.