Effects of virtual Majorana neutrinos on charged lepton flavor violation decays from a seesaw variant with radiatively induced light neutrino masses

Abstract Lepton flavor violating decays ℓ α → ℓ β γ , being forbidden in the Standard Model framework, provide a sensitive probe for new physics (NP). We study these processes in a seesaw variant in which small neutrino masses are generated radiatively. By analyzing the parameter space constrained by electroweak precision data, we investigate the correlation between these decays and non-unitary effects from TeV-scale heavy neutrinos. According to our results, μ → eγ is the most promising channel for NP searches, with the bound ∣ η μe ∣ ≲ 10 −6 obtained for non-unitary effects in this radiative seesaw variant. Our estimations of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi class="MJX-tex-calligraphic" mathvariant="script">B</mml:mi> <mml:mi class="MJX-tex-calligraphic" mathvariant="script">R</mml:mi> <mml:mfenced close=")" open="("> <mml:mrow> <mml:mi>μ</mml:mi> <mml:mo>→</mml:mo> <mml:mi>e</mml:mi> <mml:mi>γ</mml:mi> </mml:mrow> </mml:mfenced> </mml:math> , which depends on the mass of the heavy neutrinos, shows that both current and future experimental facilities might be sensitive to these effects.