Neutrino parameters, Abelian flavor symmetries, and charged lepton flavor violation

Abstract

Neutrino masses and mixings have important implications for models of fermion masses, and, most directly, for the charged lepton sector. We consider supersymmetric Abelian flavor models, where neutrino mass parameters are related to those of charged leptons and sleptons. We show that processes such as τ → µγ, µ → eγ and µ − e conversion provide interesting probes. In particular, some existing models are excluded by current bounds, while many others predict rates within reach of proposed near future experiments. We also construct models in which the predicted rates for charged lepton flavor violation are below even the proposed experimental sensitivities, but argue that such models necessarily involve loss of predictive power. 11/991 On leave of absence from Princeton University.

Search for the lepton flavor violating decayA0/H0→τ±Assamagan1, Deandrea2, Delsart3 2003Phys. Rev. D723780View full textAdd to dashboardCite

“…SUSY can accommodate the observed flavor mixing [8,9,10] and thus, the LFV processes (15), (16) and (17) would arise in these models. A study conducted at the LHC showed that an upper bound of 0.6 × 10 −6 on the τ ± → µ ± γ branching ratio can be achieved with an integrated luminosity of 30 fb −1 while theoretical estimates are at the level of 10 −9 or less [10,32].…”

“…However LFV effects can be induced by * Electronic address: ketevi@bnl.gov † Electronic address: deandrea@ipnl.in2p3.fr ‡ Electronic address: delsart@ipnl.in2p3.fr radiative corrections [6]. Large LFV effects can arise in supersymmetric models (SUSY) with a right-handed Majorana neutrino [7,8,9,10] and in SUSY with R-parity violation [11].…”

Non-universal gauge bosons Z′ and lepton flavor-violating tau decays

“…For instance, the LFV tau decays, such as τ → µγ, τ → eγ, τ → 3µ and τ → 3e, have been studied in a model independent way in Ref. [12], in the SM with extended right-handed and left-handed neutrino sectors [13], in supersymmetric 2 models [14], in the two Higgs doublets model type III [15] and in Zee model [16].…”

Charged-Lepton-Flavour Violation in the light of the Super-Kamiokande data

“…While this paper was in the final stages of preparation, we received the paper by Feng, Nir and Shadmi in [9], which makes points similar to ours, in a complimentary way.…”

“…Neutrino oscillations involve violations of the individual lepton numbers L e,µ,τ , raising the prospect that there might also exist observable processes that violate charged-lepton number conservation [4,5], such as µ → eγ, 3e and τ → µγ, 3µ/e, and µ → e conversion on heavy nuclei [5,6,7,8,9,10]. We recall briefly the present experimental upper limits on the most interesting of these decays for our subsequent discussion:…”