Indirect upper limits on ℓi →ℓjγγ from ℓi →ℓjγ

Fabiola Fortuna, Alejandro Ibarra, Xabier Marcano, Marcela Marín, Pablo Roig

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


We perform an effective field theory analysis to correlate the charged lepton flavor violating processes ℓi→ℓjγγ and ℓi→ℓjγ. Using the current upper bounds on the rate for ℓi→ℓjγ, we derive model-independent upper limits on the rates for ℓi→ℓjγγ. Our indirect limits are about three orders of magnitude stronger than the direct bounds from current searches for μ→eγγ, and four orders of magnitude better than current bounds for τ→ℓγγ. We also stress the relevance of Belle II or a Super Tau Charm Facility to discover the rare decay τ→ℓγγ.

Original languageEnglish
Article number015027
JournalPhysical Review D
Issue number1
StatePublished - 1 Jan 2023


Dive into the research topics of 'Indirect upper limits on ℓi →ℓjγγ from ℓi →ℓjγ'. Together they form a unique fingerprint.

Cite this