RF5: Charged Lepton Flavor Violation (electrons, muons and taus)

This topical group will address experimental and theoretical aspects of:

1. Muon and tau LFV reactions (mu→e gamma, mu→3e, mu-e conversion, tau decays)
2. Muonium-antimuonium oscillations and LFV leptonium decays
3. Meson and baryon LFV decays (K→ pi e mu, B → K tau ell, …)
4. Decays of heavy states (h,t,Z,Z'…) and other LFV processes at colliders
5. Light to heavy lepton LFV transitions (EIC, muon beam,…)

This topical group will benefit from the synergies with other study groups, including

• RF01 / RF02: Weak decays of b and c quarks and weak decays of strange and light quarks
• EF02/ EF09: EW Physics: Higgs Boson as a portal to new physics and BSM: More general explorations
• AF05: Accelerators for PBC and Rare Processes
• TF07: Theory Frontier - Collider Phenomenology

Past and future workshops organized by the CFLV group:

• July 2, 2020, Muon transitions and decays, muonium-antimuonium (Agenda)
• July 23, 2020, Tau decays and transitions (Agenda)
• September 3, 2020, Heavy states decays (Agenda)
• September 28-29, 2020, LFV and LFU in meson and baryon decays with RF01/RF02 (Agenda)
• December 10, CLFV with high intensity muon factory (Agenda)
• February 25, Monthly coffee hour (Agenda)
• March 25, Monthly coffee hour (Agenda)
• April 29, Monthly coffee hour (Agenda)
• May 28, Monthly coffee hour (Agenda)
• Dec 9, White paper preparation (Agenda)

Snowmass meeting (July 17-14 2022), sessions relevant for CLFV:

• CLFV in heavy state decays with EF ( Agenda)
• CLFV topical group session ( Agenda)
• CLFV and neutrino physics (Agenda)

Recording of the workshop are posted on doc-db, available here (the title doesn't always include the word recording). Please let us know (email) if you need help accessing it or wish to give a presentation

The topical group report is available here (link)

The following white papers have been submitted or planned so far:

1. Experimental Searches for Muon to Electron Conversion in a Nucleus: COMET, DeeMe, and Mu2e ( link)
2. The MEG experiment (TBA)
3. The Mu3e Experiment ( link)
4. Muonium to antimuonium conversion ( link)
5. Mu2e-II: Muon to electron conversion with PIP-II ( link)
6. CLFV in the tau sector ( link)
7. CLFV in Heavy Particle Decays ( link)
8. A New CLFV Program at Fermilab ( link)

More information can be found in this google document ( link), including the associated LOI and editor contact information.

Feel free to email us if you would like to join a group working in a specific area and we will try to match your interests.

• Snowmass 2013 Report: https://www.slac.stanford.edu/econf/C1307292/
• The 2020 European Strategy Physics input on CLFV: https://arxiv.org/pdf/1812.06540.pdf

Here is the list of submitted LOIs to this topic. First index before “/” corresponds to the primary frontier used for the submission.