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arXiv · 2010.09509

The high energy spectrum of internal positrons from radiative muon capture on nuclei

Ryan Plestid·Richard J. Hill
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Abstract

The Mu2e and COMET collaborations will search for nucleus-catalyzed muon conversion to positrons ($\mu^-\rightarrow e^+$) as a signal of lepton number violation. A key background for this search is radiative muon capture where either: 1) a real photon converts to an $e^+ e^-$ pair "externally" in surrounding material, or 2) a virtual photon mediates the production of an $e^+e^-$ pair "internally". If the $e^+$ has an energy approaching the signal region then it can serve as an irreducible background. In this work we describe how the near end-point internal positron spectrum can be related to the real photon spectrum from the same nucleus, which encodes all non-trivial nuclear physics.

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Ryan Plestid, Richard J. Hill. 2020-10-19. The high energy spectrum of internal positrons from radiative muon capture on nuclei. https://doi.org/10.1103/physrevd.103.033002

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