Related papers: Proton decay into charged leptons
Proton decay is a hypothetical form of particle decay in which protons are assumed to decay into lighter particles. This form of decay has yet to be detected. In this contribution to the proceedings of Neutrino 2022, we review the current…
Studies of lepton-flavor violation in strangeness-changing ($|\Delta S|=1$) transitions have a~long tradition in the kaon sector where they provide some of the strongest limits on physics beyond the standard model. Recent hints of violation…
Lepton flavor violating decays $\ell_{\alpha} \to \ell_{\beta} \gamma$, being forbidden in the Standard Model framework, provide a sensitive probe for new physics. We study these processes in a seesaw variant in which small neutrino masses…
We study a new supersymmetric mechanism for lepton flavour violation in muon and tau decays and muon -> e conversion in nuclei, within a minimal extension of the MSSM with low-mass heavy singlet neutrinos and sneutrinos. We find that the…
Direct searches for lepton flavor violation in decays of the $Z$ boson with the ATLAS detector at the LHC are presented. Decays of the $Z$ boson into an electron or a muon and a hadronically decaying $\tau$ lepton are considered. The…
In this paper, axion models supplemented by leptoquarks and diquarks are systematically analyzed. Turning on some couplings to and among these latter states permits to unify the Peccei-Quinn symmetry with baryon (B) and lepton (L) numbers,…
A measurement of the ratio of branching fractions $R$(J/$\psi$) = $\mathcal{B}$(B$^+_\text{c}$ $\to$ J/$\psi$$\tau^+\nu_\tau$) / $\mathcal{B}$(B$^+_\text{c}$ $\to$ J/$\psi$$\mu^+\nu_\mu$) in the J/$\psi$ $\to$ $\mu^+\mu^-$, $\tau^+$ $\to$…
The heaviness of the top quark makes its 2-body decay mode $t \to bW^+$ to be dominant, at such level that hardly any other decay mode reaches a detectable branching ratio (BR) within the SM. Here we study the decay $t \to bW^+\ell^-\ell^+$…
We study the impact of minimal non-supersymmetric models of resonant leptogenesis on charged lepton flavour violation and the neutrino mixing angle theta(13). Possible low-scale flavour realisations of resonant tau-, mu- and e-leptogenesis…
The upcoming Mu3e experiment aims to search for the lepton flavour violating decay $\mu^+ \to e^+ e^- e^+$ with an unprecedented final sensitivity of one signal decay in $10^{16}$ observed muon decays by making use of an innovative…
We assess proton decay signatures in the simplest viable $SU(5)$ model with regard to constraints on parameters governing the Standard Model fermion mass spectrum. Experimental signals for all eight two-body proton decay processes result…
The first search for the lepton number violating decay $K^+\to\pi^0\pi^-\mu^+e^+$ and lepton flavour violating decays $K^+\to\pi^0\pi^+\mu^-e^+$, $K^+\to\pi^0\pi^+\mu^+e^-$ has been performed using a dataset collected by the NA62 experiment…
The recent observation of the $K^+ \to \pi^+ \nu\bar\nu$ decay by NA62 is an important milestone in precision flavor physics. Together with evidence of $B^+ \to K^+\nu\bar\nu$ reported by Belle-II, they are the only FCNC decays involving…
Leptons with essentially the same properties apart from their mass are grouped into three families (or flavours). The number of leptons of each flavour is conserved in interactions, but this is not imposed by fundamental principles. Since…
Conventionally we collect electron and up/down-quarks (u,d)+(nu_e,e) to form unified generations, and collect the left-handed and the right-handed fermions of the same flavors (nu_e,e)+e^c. We can alternatively have a contorted multiplet,…
We analyze possible lepton-flavor-violating decays of the $Z^0$ particle in a minimal extension of the Standard Model, in which one right-handed neutral field for each family has been introduced. Such rare leptonic decays are induced by…
We briefly review the issues of proton decay and fermion masses and mixings in minimal supersymmetric grand unified theories. We argue that minimal SU(5), although tightly constrained by proton decay data, is still not ruled out. However,…
Collider searches for first-, second-, and third-generation scalar (S) or vector (V) leptoquarks (LQs) focus on the quark-lepton decay modes S,V -> q l. For SU(2)-doublet and -triplet leptoquarks with a sufficiently large splitting between…
A search for lepton-flavor and lepton-number violation in the decay of the tau lepton into one charged lepton and two charged hadrons is performed using 221.4 $\mathrm{fb}^{-1}$ of data collected at an $e^+e^-$ center-of-mass energy of…
We point out that extensions of the Standard Model with low scale (~TeV) lepton number violation (LNV) generally lead to a pattern of lepton flavor violation (LFV) experimentally distinguishable from the one implied by models with GUT scale…