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Universality in RMC for Mu2e

Jul 21, 2020, 1:15 PM


Ryan Plestid (University of Kentucky)


Radiatiave muon capture (RMC) is a key background in searches for charge-changing lepton number violation at Mu2e ($\mu^-\rightarrow e^+$). In particular there are concerns that high energy positrons, whose progenitor is either a real- or virtual-photon, can bleed into the signal region for the charge-changing search.

In this work I show positrons produced from off-shell photons can be related to the on-shell photon rate via a universal probability. This universal result is independent of the details of the virtual-photon amplitude and emerges as one approaches the end-point of the positron spectrum.

I will briefly comment on a possible asymmetry between electrons and positrons from internal conversion due to the Coulomb field of the target nucleus.

Primary author

Ryan Plestid (University of Kentucky)

Presentation materials