Related papers: On Lepton-Number-Violating Searches for Muon to Po…
We present a detailed discussion of the lepton flavour and number violating conversion of bound muons into positrons. This process is a viable alternative to neutrinoless double beta decay and, given that experiments on ordinary $\mu^-$-…
We study the lepton-flavor-violating reaction $\mu^+ e^- \to e^+ e^-$ within two extensions of the standard model that include heavy neutrinos. The reaction is studied in the low energy limit in the form of muonium decay $M\to e^+ e^-$ and…
Lepton-number violation (LNV), in general, implies nonzero Majorana masses for the Standard Model neutrinos. Since neutrino masses are very small, for generic candidate models of the physics responsible for LNV, the rates for almost all…
The flavour violating neutrinoless muon decays in the presence of nuclei, are discussed. We focus on the theoretical aspects of $\mu^-(A,Z)\to e^-(A,Z)^*$ (muon-to-electron conversion), one of the most prominent flavour changing reactions,…
The $e^- e^-$ mode with lepton number $L=+2$ of the initial state is particularly suitable for studying lepton and flavor number violating reactions (LFV). In this brief report we give a summary of the study of two loop-level reactions…
The physics responsible for neutrino masses and lepton mixing remains unknown. More experimental data are needed to constrain and guide possible generalizations of the standard model of particle physics, and reveal the mechanism behind…
Dedicated experiments searching for lepton flavour violation can be performed very sensitively using K-decays and $\mu$-decays as well as neutrinoless double $\beta$-decay and muonium to antimuonium conversion. Although there is no…
Observation of lepton number violation would represent a groundbreaking discovery with profound consequences for fundamental physics and as such, it has motivated an extensive experimental program searching for neutrinoless double beta…
In the absence of a fundamental principle preventing charged lepton flavour violation, one expects that extensions of the Standard Model accommodating neutrino masses and mixings should also allow for charged lepton flavour violating…
We survey 129 lepton number violating effective operators, consistent with the minimal Standard Model gauge group and particle content, of mass dimension up to and including eleven. Upon requiring that each one radiatively generates the…
A natural explanation for the smallness of the neutrino mass requires them to be Majorana particles violating lepton number by two units. Since lepton number violation can have several interesting consequences in particle physics and…
The search for lepton flavour violation in charged lepton decays is highly sensitive to physics beyond the Standard Model. Among the possible processes, $\mu$-decays are considered to have the largest discovery potential in most of the…
We show that lepton number violating muon decays, \mu^+ -> e^+ + \nu_e-bar + \nu_i-bar (i=e, \mu or \tau), can consistently explain the neutrino anomaly reported by the LSND experiment. Two effective operators in the Standard Model are…
Charged lepton flavor violation arises in the Standard Model Effective Field Theory at mass dimension six. The operators that induce neutrinoless muon and tauon decays are among the best constrained and are sensitive to new-physics scales…
We consider four lepton-number violating (\lv) processes: (a) neutrinoless double-beta decay (0\nu\beta\beta), (b) Delta L = 2 tau decays, (c) Delta L = 2 rare meson decays and (d) nuclear muon-positron conversion. In the absence of exotic…
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…
The conservation of lepton flavor is a prediction of the Standard Model and is still an excellent approximate symmetry despite our observation of neutrino oscillations. Lepton flavor violation by one or two units have been discussed for…
In supersymmetric extensions of the Standard Model, the Yukawa and/or mass terms of the heavy neutrinos can generate lepton flavour violating slepton mass terms. These new supersymmetric sources of lepton flavour violation may both enhance…
Lepton flavor violation (LFV) has been discovered in the neutrino sector by neutrino oscillation experiments. The minimally extended Standard Model (SM) to include neutrino masses allows LFV in the charged sector (CLFV) at the loop-level,…
We suppose that the observed neutrino masses can be parametrised by a lepton number violating dimension-five operator, and calculate the mixing of double insertions of this operator into lepton flavour changing dimension-six operators of…