R-parity stands as an ad hoc assumption in the most popular version of the supersymmetric standard model. More than fifteen years’ studies of R-parity violations have been restricted to various limiting scenarios. We illustrate how the single-VEV parametrization provides a workable framework to analyze the phenomenology of the complete theory of supersymmetry without R-parity. In our comprehens...

Phenomenological aspects of avor changing processes are considered in the context of the supergravity model. Various avor changing neutral current processes in B and K decays are calculated in such models. For lepton avor violating processes the + ! ee branching ratio and the T odd triple vector correlation for the + ! e + e + e ? process are investigated in the SU(5) SUSY GUT. Possibility to n...

Motivated by the prospects for an improved test of lepton universality in K → lν decays by the NA62 experiment at CERN, we study predictions for the possible lepton nonuniversality in K → lν decays in supersymmetric models. Violations of μ− e universality in this process may originate from mixing effects in the right-handed slepton sector, providing a unique window into this aspect of supersymm...

Some of the motivations for quark and lepton compositeness, and some problems associated with present schemes, are noted. One model is discussed in which quarks and leptons are taken as composites of spin-1/2 fermions F with charges ±1/2 and spinless bosons S̄ with charges 1/6 and −1/2.

This article reviews and updates the Standard Model prediction of the τ lepton g−2. Updated QED and electroweak contributions are presented, together with new values of the leading-order hadronic term, based on the recent low energy ee data from BaBar, CMD-2, KLOE and SND, and of the hadronic light-by-light contribution. The total prediction is confronted to the available experimental bounds on...

In models where the Standard Model spectrum is localized on a brane embedded in a higher dimensional spacetime, we discuss the lepton number violation induced by the emission of right-handed neutrinos from the brane. We show that quite generically the presence of the right-handed neutrinos in the bulk leads to rapid lepton number violating processes which above the electroweak scale would wash ...

We address the issue of lepton flavour violation and neutrino masses in the “fat-brane” paradigm, where flavour changing processes are suppressed by localising different fermion field wave-functions at different positions (in the extra dimensions) in a thick brane. We study the consequences of suppressing lepton number violating charged lepton decays within this scenario for lepton masses and m...

We show that in supersymmetric models with explicit flavor lepton number violation due to soft supersymmetry breaking mass terms there must be flavor lepton number violation in slepton decays. We propose to look for flavor lepton number violation in righthanded selectron and smuon decays. For selectron and smuon lighter than 80 Gev flavor lepton number violation in slepton decays could be disco...