Related papers: Probing New Physics through mu-e Universality in K…
We confront the indications of lepton flavor universality (LFU) violation observed in semi-tauonic $B$ meson decays with new physics (NP) searches using high $p_T$ tau leptons at the LHC. Using effective field theory arguments we correlate…
We present an overview of searches fo violation of lepton flavor universality with focus on low energy precision probes using pions, kaons, tau leptons, and nuclear beta decays. The current experimental results are reviewed, the theoretical…
The purely leptonic decays D -> e nu and Ds -> e nu, for which no experimental limits exist, are highly suppressed in the Standard Model. Mere observation of these decays at the B factories BELLE/BaBar or forthcoming CLEO-c would be a clear…
Several experiments reported hints for the violation of lepton flavor or lepton flavor universality in processes involving muons. Most prominently, there is the hint for a non-zero rate of the flavor violating Higgs decay $h \to \tau\mu$ at…
We study charged lepton flavour violation in low-scale seesaw models of minimal supergravity, which realize large neutrino Yukawa couplings thanks to approximate lepton-number symmetries. There are two dominant sources of lepton flavour…
We present an extensive analysis of rare K decays, in particular of the two neutrino modes K+->pi+ nu nu-bar and KL->pi0 nu nu-bar, in the Minimal Supersymmetric extension of the Standard Model. We analyse the expectations for the branching…
Within the assumption of Left-Handed (LH) New Physics (NP), we review the relations between $\mathcal{B}(B\to K^{(\ast)} \tau^+\tau^-)$ and $\mathcal{B}(B\to K^{(\ast)} \nu\bar \nu)$ for several Beyond the Standard Model (BSM) scenarios,…
We present a general analysis of B_{s,d}-> l^+ l^- and K_L -> l^+ l^- decays in supersymmetric models with non-minimal sources of flavour mixing. In spite of the existing constraints on off-diagonal squark mass terms, these modes could…
We consider lepton flavor violations (LFV) mediated by photino as a result of the nondiagonal slepton mass matrices in general supersymmetric models. Using the experimental upper bounds on l \to l' + gamma and mu^- + Ti \to e^- + Ti as…
We construct a semi-inclusive Lepton Flavour Universality (LFU) ratio, $R_\Sigma$, to test $\mu/e$ universality in $b\to s\ell^+\ell^-$ transitions at $e^+e^-$ $B$-meson factories. Combining different decay channels, this observable…
Recent MEG results of a search for the lepton flavor violating (LFV) muon decay, $\mu \to e \gamma$, show 3 events as the best value for the number of signals in the maximally likelihood fit. Although this result is still far from the…
A lepton-flavor violating (LFV) Z' boson may mimic some of the phenomena usually attributed to supersymmetric theories. Using a conservative model of LFV Z' bosons, the recent BNL E821 muon g-2 deviation allows for a LFV Z' interpretation…
We analyse the contributions to the charge asymmetry in $K^\pm\to\pi^\pm\ell^+\ell^-$ decays induced by gluino-exchange diagrams in the context of supersymmetric models with generic flavour couplings. We show that sizeable deviations with…
The recent results from the Fermilab muon $g-2$ experiment, as well as the persisting hints of lepton flavor universality violation in $B$-meson decays, present a very strong case for flavor-nonuniversal new physics beyond the Standard…
The dominant MSSM effects in the rare K decays, K+ --> pi+ nu nu bar, KL --> pi0 nu nu bar, KL --> pi0 e+ e- and KL --> pi0 mu+ mu-, are discussed both within and without the minimal flavor violation hypothesis, at moderate and large…
A recent proposal for explaining discrepancies in angular observables in the rare decay B --> K*mu+mu- with a gauged L_mu - L_tau current carried with it the prediction of lepton flavor universality violation in related B-meson decays. This…
331 models constitute an extension of the Standard Model (SM) obtained by enlarging the SM gauge group $SU(3)_\text{C}\times SU(2)_\text{L}\times U(1)_Y$ to the group $SU(3)_\text{C}\times SU(3)_\text{L}\times U(1)_X$. We investigate how a…
Lepton-flavour violating processes, such as $\mu \to e\gamma$, are studied in ordinary (non-SUSY) SU(5) and SUSY SU(5) grand unified theories. First given are some introductory argument on the mechanism of U.V. divergence cancellation in…
We explore a scenario of New Physics entering the description of $B\to K^{(\ast )} \mu \mu$ decay through couplings to the operators ${\cal O}_{9,10}^\prime$, satisfying $C_9^\prime = - C_{10}^\prime$. From the current data on ${\cal…
Recent observations of neutrino oscillations imply non-zero neutrino masses and flavor violation in the lepton sector, most economically explained by the seesaw mechanism. Within the context of supersymmetry, lepton flavor violation (LFV)…