Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published August 1, 2013 | public
Journal Article

The calorimeter project for the Mu2e experiment


The Mu2e experiment at Fermilab aims to measure the charged lepton flavor violating neutrinoless conversion of a negative muon into an electron. The conversion results in a monochromatic electron with an energy slightly below the rest mass of the muon (104.97 MeV). We expect to set a limit of ∼ 6×10^(−17) at 90% CL in three years of running, using an intense and clean pulsed μ^− beam providing ∼10^(18) stopped muons on target in three years of running. The experiment performs a strong suppression of potential background by gating off the prompts and performing precise momentum determination in conjunction with an highly efficient cosmic veto. The calorimeter should confirm that the candidates reconstructed by the tracker system are indeed conversion electrons and provide an independent trigger (or event reduction filter) for the experiment. It should also provide standalone muon to electron rejection. Moreover, it must be able to keep functionality in a high radiation dose environment inside a 10^(−4)_(torr) vacuum enclosure and in a presence of 1 T axial magnetic field. In order to accomplish all these tasks, a LYSO crystals calorimeter has been chosen. We show the proposed design and the experimental results obtained by exposing a small size calorimeter prototype to a tagged photon beam from 40 to 300 MeV at the A2 photon facility of the Mainz Microton (MAMI), Germany.

Additional Information

© 2012 Elsevier B.V. Available online 5 December 2012. The authors are grateful to many people for the successful realization of the matrix. Inparticular, we thank all the LNF mechanical shop for the realization of the support and APD boxes, especially G. Bisogni, U. Martini and A. DePaolis. We also thank the MAMI staff for providing the beam time. The realization of the preamplifiers was done in collaboration with E. Reali from the University of Rome "Tor Vergata".

Additional details

August 22, 2023
October 24, 2023