相关论文: Muon Number Violating Processes in Single Particle…
The Standard Model (SM) is augmented with a $\mathrm{U}(1)_{B-3L_\mu} $ gauge symmetry spontaneously broken above the TeV scale when an SM-singlet scalar condenses. Scalar leptoquarks $S_{1(3)} = (\overline{\mathbf{3}},\, \mathbf{1}…
We present the first detailed computation of the conversion of a bound muon into an electron mediated by a doubly charged $SU(2)$ singlet scalar. Although such particles are not too exotic, up to now their contribution to $\mu$-$e$…
It is shown that a minimal extension of the standard model with leptons that transform as singlets under the SU(2) symmetry of weak interactions can explain the recently reported derivation in the measured value of the anomalous magnetic…
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…
We study the rare decays of charged \pi\ mesons, \pi+ to e+ e+ \mu- anti-\nu_\mu\ and \pi+ to e+ \mu- e+ \nu_e, induced by a sterile neutrino N with a mass in the range m_\mu < m_N < m_\pi. The first process violates Lepton Number by two…
Simple dynamics, few available decay channels, and extremely well controlled radiative and loop corrections, make pion and muon decays a sensitive means for testing the underlying symmetries, the universality of weak fermion couplings, as…
Using an effective lagrangian description we analyze possible new physics contributions to the most relevant muon number violating processes: $\mu \to e \gamma$ and $\mu$--$e$ conversion in nuclei. We identify a general class of models in…
Models involving large extra spatial dimension(s) have interesting predictions on lepton flavor violating processes. We consider some 5D models which are related to neutrino mass generation or address the fermion masses hierarchy problem.…
We classify all possible one-particle (scalar and fermion) extensions of the Standard Model that can contribute to the anomalous magnetic moment of leptons. We review the cases already discussed in the literature and complete the picture by…
Extensions of the standard model (SM) with gauge symmetry SU(3)_c X SU(4)_L X U(1)_X (3-4-1 extensions) where anomaly cancellation takes place between the fermion families (three-family models) predict the existence of two new heavy neutral…
We study the simplest renormalizable scalar leptoquark models where the standard model is augmented only by one additional scalar representation of SU(3) x SU(2) x U(1). The requirement that there be no proton decay from renormalizable…
In light of the recent result published by the Fermilab Muon $(g-2)$ experiment, we investigate a simple model that includes particles of fractional electric charges: a colour-singlet fermion and a scalar with charges $2/3e$ and $1/3e$,…
One loop corrections to the muon decay are studied in a popular and self-consistent version of the Left-Right symmetric model. It is shown quantitatively, that the corrections do not split into those that come from the Standard Model sector…
We propose a standard model minimal extension with two lepton weak SU(2) doublets and a scalar singlet to explain the deviation of the measured anomalous magnetic moment of the muon from the standard model expectation. This scheme can be…
We discuss charged lepton flavour violating processes occurring in the presence of muonic atoms, such as muon-electron conversion in nuclei $\text{CR}(\mu -e, \text{ N})$, the (Coulomb enhanced) decay of muonic atoms into a pair of…
We briefly overview some theoretical aspects of charged lepton flavour violation in rare muon transitions and decays. Relying on the effective field theory approach (model-independent), we discuss the probing power of charged lepton flavour…
Recent measurements of $b\to s\mu^+\mu^-$ processes at LHCb and BELLE have revealed tensions at the $2-3\,\sigma$ level between the Standard Model (SM) prediction and the experimental results in the channels $B\to K^*\mu^+\mu^-$ and…
In the present work we review the most prominent lepton flavor violating processes ($\mu \ra e\gamma$, $\mu \ra 3e$, $(\mu , e)$ conversion, $M-\bar M$ oscillations etc), in the context of unified gauge theories. Many currently fashionable…
The experimental observation of lepton-number violating processes would unambiguously indicate the Majorana nature of neutrinos. Various $\Delta L$ = 2 processes for pseudoscalar meson $M_1$ decays to another pseudoscalar meson $M_2$ and…
Physics from beyond the Standard Model can induce four fermion operators involving a quark, an anti-quark, a lepton and an anti-lepton. The coefficients of these operators can be constrained by various observations. We update the bounds…