Measurement of Inner Bremsstrahlung in Polarized Muon Decay with MEG

J. Adam, X. Bai, A. M. Baldini, E. Baracchini, C. Bemporad, G. Boca, P. W. Cattaneo, G. Cavoto, F. Cei, C. Cerri, A. de Bari, M. De Gerone, T. Doke, S. Dussoni, J. Egger, K. Fratini, Y. Fujii, G. Galli, L. Gallucci, F. GattiB. Golden, M. Grassi, D. N. Grigoriev, T. Haruyama, M. Hildebrandt, Y. Hisamatsu, F. Ignatov, T. Iwamoto, P. R. Kettle, B. I. Khazin, O. Kiselev, A. Korenchenko, N. Kravchuk, A. Maki, S. Mihara, W. Molzon, T. Mori, D. Mzavia, H. Natori, D. Nicolò, H. Nishiguchi, Y. Nishimura, W. Ootani, M. Panareo, A. Papa, R. Pazzi, G. Piredda, A. Popov, F. Renga, S. Ritt, M. Rossella, R. Sawada, F. Sergiampietri, G. Signorelli, S. Suzuki, F. Tenchini, C. Topchyan, Y. Uchiyama, R. Valle, C. Voena, F. Xiao, S. Yamada, A. Yamamoto, S. Yamashita, Yu V. Yudin, D. Zanello

Research output: Contribution to journalArticlepeer-review


A muon decay accompanied by a photon through the inner Bremmstrahlung process (μ→eνν-γ, radiative muon decay) produces a time-correlated pair of positron and photon which becomes one of the main backgrounds in the search for μ→. eγ decay. This channel is also an important probe of timing calibration and cross-check of whole the experiment. We identified a large sample (~ 13000) of radiative muon decays in MEG data sample. The measured branching ratio in a region of interest in the μ→. eγ search is consistent with the standard model prediction. It is also the first measurement of the decay from polarized muons. The precision measurement of this mode enables us to use it as one of the normalization channels of μ→. eγ decay successfully reducing its uncertainty to less than 5%.

Original languageEnglish
Pages (from-to)108-111
Number of pages4
JournalNuclear Physics B - Proceedings Supplements
Publication statusPublished - 2014
Externally publishedYes

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Nuclear and High Energy Physics


Dive into the research topics of 'Measurement of Inner Bremsstrahlung in Polarized Muon Decay with MEG'. Together they form a unique fingerprint.

Cite this