Related papers: Muon-electron conversion in strange quark sea
The Standard Model (SM) is amended by one generation of quarks and leptons which are vector-like (VL) under the SM gauge group but chiral with respect to a new $\mathrm{U}(1)_{3-4}$ gauge symmetry. We show that this model can simultaneously…
We explore models where single new exotic states interact with the Standard Model through an asymmetric Standard Model portal with couplings to at least one quark and one lepton. All effective operators up to dimension six where such…
Constraints from the muon anomalous magnetic dipole moment and lepton flavor violating processes are translated into lower bounds on v_Delta*m_H++ in the Higgs Triplet Model by considering correlations through the neutrino mass matrix. The…
We consider charged lepton flavor violating transitions mediated by the diphoton effective interactions $\ell_i\ell_j\gamma\gamma$ and explore which processes can probe them better. Our analysis includes single and double radiative decays,…
Lepton flavour violation (LFV) naturally occurs in many new physics models, specifically in those explaining the $B$ anomalies. While LFV has already been studied for mesonic decays, it is important to consider also baryonic decays mediated…
We chart new-physics models that produce exotic, high-multiplicity muon decays featuring prompt or displaced $e^+e^-$ pairs and/or photons, with or without missing energy, such as $\mu \to 5e$, $\mu \to 7e$, etc. Starting from an…
The impact of rare lepton decays ($\mu \to e \gamma$, $\tau \to \mu \gamma$, >...) and rare $B$ and $K$ decays ($B\to \ell^+\ell^-$, $B\to \ell\nu$, $K\to \pi \nu\nu$, $K\to\ell\nu$, ...) in probing the existence of an underlying flavour…
We show that new physics models without new flavor violating interactions can explain the recent anomalies in the $b\to s\ell^+\ell^-$ transitions. The $b\to s\ell^+\ell^-$ arises from a $Z'$ penguin which automatically predicts the $V-A$…
We propose a model to explain several muon-related experimental anomalies and the abundance of dark matter. We introduce an vector-like exotic lepton that form an iso-doublet and three right-handed Majorana fermions as an iso-singlet. A…
A positive muon ($\mu^+$) and an electron ($e^-$) form the the hydrogen-like muonium atom ($M$=$\mu^+ e^-$). Since it consists of two leptonic particles which are according to present knowledge point-like, accurate calculations of its level…
In supersymmetric models new sources of lepton flavour violation (LFV) may enhance the rates of charged lepton flavour violating processes, like mu to e gamma, and generate distinct final states at future colliders, e.g. tau mu + jets +…
Tau leptons can have lepton-flavor-violating (LFV) couplings to a muon or an electron and an Axion-Like Particle (ALP). ALPs are pseudo Nambu-Goldstone bosons associated with spontaneously broken global U(1) symmetries. LFV ALPs have been…
The observation of lepton flavor violation indicates new physics beyond the Standard Model. Lepton colliders are ideal facilities to probe charged lepton flavor violation (CLFV) signals induced by new physics at high energy. In this work we…
Upcoming experiments will improve the reach for the lepton flavour violating (LFV) processes $\mu \to e \gamma$, $\mu \to e \bar{e} e$ and $\mu A \to e A$ by orders of magnitude. We investigate whether this upcoming data could rule out some…
The lepton flavour violating signals $e^{+}e^{-}\to \ell^{+}e^{-}$ and $e^{-}e^{-}\to \ell^{-}e^- (\ell=\mu,\tau)$ are studied in the context of low energy R-parity conserving supersymmetry at center of mass energies of interest for the…
We assess the status of past and future experiments on lepton flavor violating (LFV) muon and tau decays into a light, invisible, axion-like particle (ALP), $a$. We propose a new experimental setup for MEG II, the MEGII-fwd, with a forward…
We investigate flavor-changing neutral current (FCNC) interactions of the top quark at a future muon collider with a center-of-mass energy of $\sqrt{s} = 10~\mathrm{TeV}$. The process $\mu^{+}\mu^{-} \to \nu_{\mu}\,\mu^+\,b\,j$ and its…
The dimension-six CP-conserving $SU_L(2)\times U_Y(1)$ invariant operators involving the tau lepton are studied. It leads to the new physics effects to the lepton flavor violation (LFV) and lepton flavor-changing neutral current(FCNC). With…
We study a class of nonstandard interactions of the newly discovered 125 GeV Higgs-like resonance that are especially interesting probes of new physics: flavor violating Higgs couplings to leptons and quarks. These interaction can arise in…
The coherent muon-electron conversion rates in various nuclei are calculated for general lepton flavor violating interactions. We solve the Dirac equations numerically for the initial state muon and the final state electron in the Coulomb…