Related papers: LFU violations in leptonic $\tau$ decays and B-phy…
Lepton flavour violation has been proposed as a significant test of supersymmetric unification. Here we show that such signals are also a generic feature of supersymmetric string unified models in which there is no simple unified gauge…
$\tau$ is playing an important role in the current B-physics indications from experiments of lepton flavor universality violations(LFUV). This suggests it be given increasing attention theoretically in the coming years, given also the fact…
The study of lepton flavor universality violation (LFUV) in semitauonic $b$-hadron decays has become increasingly important in light of longstanding anomalies in their measured branching fractions, and the very large datasets anticipated…
We construct an extension of the Standard Model with a scalar leptoquark $\phi \sim (3,1,-\tfrac13)$ and the discrete flavour symmetry $G_f=D_{17}\times Z_{17}$ to explain anomalies observed in charged-current semi-leptonic $B$ meson decays…
We perform a global analysis of the bounds from charged lepton flavour violating observables to new physics. We parametrize generic new physics through the Effective Field Theory formalism and perform global fits beyond the common…
In the past few years, several hints of lepton flavour universality (LFU) violation have emerged in the $b \to c \tau \bar\nu$ and $b \to s \ell^+ \ell^-$ data. Quite recently, the Belle Collaboration has reported the first measurement of…
Motivated by flavour symmetry models, we construct theories based on a low-energy limit featuring lepton flavour triality that have the flavour-violating decays $\tau^\pm \to \mu^\pm \mu^\pm e^\mp$ and $\tau^\pm \to e^\pm e^\pm \mu^\mp$ as…
Analytic expressions of lepton-flavour- and lepton-number-violating decays of charged leptons are derived in the context of general $SU(2)_L\otimes U(1)_Y$ seesaw scenarios that are motivated by grand unified theories (GUT's) or superstring…
We calculate the predictions for lepton flavour violating (LFV) tau and muon decays, $l_j \to l_i \gamma$, $l_j \to 3 l_i$, $\mu-e$ conversion in nuclei and LFV semileptonic tau decays $\tau \to \mu PP$ with $PP= \pi^+\pi^-, \pi^0\pi^0,…
We investigate the constraint on the split fermions in extra dimensions by considering the universality of $W$ leptonic decays $W\to l_i \nu_i$, the charged lepton decays $l_i \ra l_j\nu_i\bar{\nu}_j$, and the lepton flavor violating…
The deviations with respect to the Standard Model (SM) that are currently observed in $b \to s \ell\ell$ transitions (the so-called flavour anomalies) can be interpreted in terms of different New Physics (NP) scenarios within a…
We investigate the flavor violation (FV) of Z decays to leptons at tree level and flavor conserving Z decays to leptons in the frame work of the flipped $ SU(3)_C\otimes SU(3)_L \otimes U(1)_X\otimes U(1)_N$,(F3311) model. In addition, we…
The LHCb Collaboration's measurement of R_K = B(B+ -> K+ mu+ mu-)/B(B+ -> K+ e+e-) lies 2.6 sigma below the Standard Model prediction. Several groups suggest this deficit to result from new lepton non-universal interactions of muons. But…
Motivated by the recent anomalies observed in semileptonic decays of B-mesons, the class of models denoted as "4321" is introduced and analysed. The importance of calculating next-to-leading-order (NLO) effects in performing precise…
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…
The flavor-changing neutral current semileptonic decays of $B$ mesons provide an excellent platform for indirectly probing New Physics (NP) beyond the Standard Model (SM). Recent measurements of lepton flavor universality (LFU) ratios such…
In the context of flavor-universal topcolor-assisted technicolor (TC2) models, we calculate the lepton flavor violating (LFV) $Z\to l_il_j$ decays. We find that the extra U(1) gauge boson $Z^{\prime}$ can give significant contributions to…
This Thesis presents my personal contributions to two distinct fields, namely the recent experimental anomalies in B-meson decays, and the longstanding quest for a theoretical explanation of lepton masses and mixings, under a unifying…
The RK measurement by LHCb suggests non-standard lepton-universality violation (LUV) to occur in b to s l+ l- decays, with effects in muons rather than electrons. It is intriguing that a number of other measurements of b to s l+ l-…
We study lepton flavor violation (LFV) in tau decays induced by heavy Majorana neutrinos within two models: (I) the Standard Model with additional right-handed heavy Majorana neutrinos, i.e., a typical seesaw-type model; (II) the Standard…