New constraint on the existence of the μ+ → e+ γ decay.
نویسندگان
چکیده
The analysis of a combined data set, totaling 3.6 × 10(14) stopped muons on target, in the search for the lepton flavor violating decay μ(+) → e(+)γ is presented. The data collected by the MEG experiment at the Paul Scherrer Institut show no excess of events compared to background expectations and yield a new upper limit on the branching ratio of this decay of 5.7 × 10(-13) (90% confidence level). This represents a four times more stringent limit than the previous world best limit set by MEG.
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
متن کاملar X iv : h ep - p h / 02 12 26 2 v 1 1 8 D ec 2 00 2 Interference of Conversion and Bremsstrahlung Amplitudes in the Decay K L → μ + μ − γ
In the region of large μ+μ− invariant mass, the decay spectrum of KL → μ +μ−γ deviates from the Dalitz pair spectrum, as a result of interference between conversion (KL → γ ∗γ → μ+μ−γ) and bremsstrahlung amplitudes. The latter is proportional to the KL → μ +μ− matrix element, whose 2γ-absorptive part appears to dominate the observed KL → μ +μ− decay rate. We examine the extent to which a scruti...
متن کاملتحلیل پارامتر ضریب چسبندگی کل و تعیین شرایط بهینه همجوشی کاتالیزور میونی بادرنظرگرفتن مولکول شبه پایدارdt μ
Recently a new process has been suggested by Froelich and Wallenius in μ CF. They predicted a high rate of formation of an excited meta-stable in the collision of excited tμ(2s) with D2, which will then decay into dμ (1s). It produces the reversing transfer channel. In this paper, we establish a new approach in study of determination of q1sand p1sparameters, where p1s is the fractional pop...
متن کاملMuon decays with lepton–number violation via vector leptoquark
The decays μ → eγ, μ → eγγ, and μ → eeē are analysed in the framework of the Pati-Salam type quark-lepton symmetry SU(4)V ⊗ SU(2)L⊗GR where the effects of mixing in the quark-lepton currents are taken into account. It is shown that the μ → eγγ and μ → eeē decays via the vector leptoquark have not a GIM–type suppression, while the μ → eγ decay has. So, the specific hierarchy of the decay probabi...
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 کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 110 20 شماره
صفحات -
تاریخ انتشار 2013