Targeting Studies for a Second-Generation Mu2e Experiment

Abstract

Charged-lepton-flavor violation (CLFV) is a clear signal of physics beyond the Standard Model. The Mu2e experiment at Fermi National Accelerator Laboratory searches for CLFV through muon-to-electron conversion, aiming to reach a sensitivity four orders-of-magnitude beyond the current limits. The target of a next-generation Mu2e experiment (Mu2e-II) is to achieve a sensitivity approximately a factor ten better than the Mu2e experiment. An 800 MeV proton beam with maximum power of 100 kW will be available after the completion of the Proton Improvement Plan II. The potential of using the 800 MeV beam for Mu2e-II was studied by simulations using G4beamline. The number of stopped muons at the stopping target per kilowatt dropped by a factor of 1.633, indicating Mu2e-II will produce 7.653 times more stopped muons than Mu2e during 3 years. The proton beam can be delivered to the production target by modifying the magnets of the beam transport; however, it requires serious reconfiguration of the facilities including the beam transport, position of the production target, and the holes of the transport solenoid.