Holographic Reconstruction of Electron Momenta for the Detection of Muon-to-Electron Conversion via Synchrotron Radiation Emission

The detection of charged lepton flavor violating (CLFV) processes would be a major development, signifying new physics beyond the Standard Model. Muon transitions have established stringent constraints on CLFV processes, and the upcoming generation of experiments will improve current limits by four orders of magnitude [1,2]. Mu2e will measure momentum-dependent electron trajectories using an array of straw tubes, and COMET will use a cylindrical drift chamber, but the momentum resolutions of these technologies are limited by multiple scattering in the detector material. We explore the feasibility of using the emitted synchrotron radiation of the conversion electrons in a magnetic field for momentum reconstruction. Depending on the magnetic field, some of the synchrotron radiation from a 105 MeV electron will lie in the visible band, so a detector composed of a hollow cylinder of pixelated photodetector panels arranged around the electron production point would leave electron paths unobstructed. In this talk, I will present the likelihood-based reconstruction techniques used to extract electron parameters from a sparse track of photon hits. Also, the dependence of physics-sensitive momentum resolutions on the detector parameters will be discussed.

References

[1] Bernstein, R. H. (2019). The Mu2e experiment. Frontiers in Physics, 7(JAN), 421268.

[2] Lee, M. J. (2018). COMET muon conversion experiment in J-PARC. Frontiers in Physics, 6(NOV), 415345.