KEK Preprint 97 - 113 Observation of the Decay K + → π + γγ
نویسنده
چکیده
The first observation of the decay K+ → π+γγ is reported. A total of 31 events was observed with an estimated background of 5.2±3.3 events in the π+ momentum range from 100 MeV/c to 180 MeV/c. The corresponding partial branching ratio, B(K+ → π+γγ, 100 MeV/c < Pπ+ < 180 MeV/c), is (6.0±1.4{stat}±0.7{sys})×10−7. No K+ → π+γγ decay was observed in the π+ momentum region greater than 215 MeV/c. The observed π+ momentum spectrum is compared with the predictions of chiral perturbation theory. PACS numbers: 13.20.Eb, 12.39.Fe, 13.40.Hq Typeset using REVTEX
منابع مشابه
O ct 1 99 7 BNL - 64627 PRINCETON / HEP / 97 - 11 TRI – PP – 97 – 27 KEK Preprint 97 - 114 Observation of the Decay K + → π + μ + μ −
We have observed the rare decay K+→π+μ+μ− and measured the branching ratio Γ(K+→π+μ+μ−)/Γ(K+→all) = (5.0± 0.4stat ± 0.7syst ± 0.6th)× 10−8. We compare this result with predictions from chiral perturbation theory and estimates based on the decay K+→π+e+e−. PACS numbers: 13.20.Eb, 12.39.Fe Typeset using REVTEX
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تاریخ انتشار 1997