Related papers: Lepton flavour violating B meson decays via scalar…
We revisit the possibilities of accommodating the experimental indications of the lepton flavor universality violation in $b$-hadron decays in the minimal scenarios in which the Standard Model is extended by the presence of a single…
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…
Starting from the general effective hamiltonian relevant to the $b\to s$ transitions, we derive the expressions for the full angular distributions of the $B \to K^{(\ast )} \ell_1 \ell_2$ decay modes, as well as for ${\cal B}(B_s \to…
Lepton flavor universality violating $B\to K\ell\ell$ and $K^*\ell\ell$ decays tentatively observed by LHCb can be explained by leptoquark exchange. We explore a simple model for the $B$ anomalies with a composite leptoquark from new strong…
Semileptonic B meson decays induced by $b \to s(d) l^+ l^-$ flavour changing neutral current (FCNC) transitions are very important to probe the quark-flavour sector of the standard model (SM) and also offer a probe to test new physics (NP).…
We consider the leptonic and semileptonic (SL) lepton flavour violating (LFV) decays of the charged leptons in the minimal supersymmetric standard model (MSSM). The formalism for evaluation of branching fractions for the SL LFV…
Leptoquarks are hypothetical new particles, which couple quarks directly to leptons. They experienced a renaissance in recent years as they are prime candidates to explain the so-called \textit{flavor anomalies}, i.e. the deviations between…
Hints of violation of lepton flavor universality in semileptonic $B$ decays have prompted a renewed interest in leptoquarks at the low TeV scale. Among the different scenarios suggested, some happen to violate also lepton number, yet not…
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…
Studies of lepton-flavor violation in strangeness-changing ($|\Delta S|=1$) transitions have a~long tradition in the kaon sector where they provide some of the strongest limits on physics beyond the standard model. Recent hints of violation…
We consider lepton-flavor violation in strangeness changing ($|\Delta S|=1$) semileptonic $\tau$-lepton decays arising from new physics encoded in a standard model effective Lagrangian. Its invariance under the standard model gauge group…
An overview of ATLAS and CMS studies of B_s leptonic decays providing constraints on the lepton flavour violation phenomenon is presented. Except direct lepton flavour violating final states B_s -> l_1^+ l_2^-, constraints can also be set…
We analyze $K\to \pi \nu\bar \nu$ rates in a model with a TeV-scale leptoquark addressing $B$-meson anomalies, based on the flavor non-universal 4321 gauge group featuring third-generation quark-lepton unification. We show that, together…
The semileptonic decays of $B_q$ mesons ($q=u,d,s$) to $J^P=2^+$ charmed mesons are investigated. The form factors parametrising the hadronic matrix elements of the weak vector and axial-vector quark currents are evaluated using light-cone…
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…
Driven by the recent experimental hints of lepton-flavor-universality violation in the bottom-quark sector, we consider a simple extension of the Standard Model (SM) with an additional vector leptoquark $V_{\rm LQ}({\bf 3},{\bf 1},2/3)$ and…
Rare $K \to \pi \nu \bar \nu$ decays, being dominated by short distance contributions within the Standard Model (SM), open a window for New Physics (NP) searches at low energies. The $ K \to \pi \nu \bar\nu $ branching ratios are expected…
The N-B-LSSM is an extension of the minimal supersymmetric standard model (MSSM) with the addition of three singlet new Higgs superfields and right-handed neutrinos, whose local gauge group is $SU(3)_C\times SU(2)_L\times U(1)_Y\times…
In recent years, lepton flavour violating (LFV) decays are one of the most trending topics to probe new physics (NP). The latest results of LHCb have motivated us to study the LFV decays through b to s transition. The branching ratios,…
The $B$-physics experiments at LHCb, BaBar and Belle hint towards deviations from Lepton Flavor Universality in both the tree-level and loop-induced $B$ meson semileptonic decays. We propose a leptoquark model with light right-handed…