相关论文: Lepton flavour universality violation from composi…
The flavor changing rare decay $B\to K^{*}(\to K\pi)\ell^+\ell^-$ is one of the most studied modes due to its sensitivity to physics beyond the standard model and several discrepancies have come to light among the plethora of observables…
We study the flavor universality of the lepton couplings with the W and Z bosons. Currently, it is constrained by the electroweak precision observables. We focus on the leptonic decay of the pion. It is shown that the decay is expected to…
The basic features of quark and lepton mass matrices can be successfully explained by natural minima of a generic potential with dynamical Yukawa fields invariant under the $[\mathrm{SU(3)}]^5\times \mathcal{O}(3)$ flavor symmetry. If this…
The LHCb has measured the ratios of $B\to K^\ast\mu^+\mu^-$ to $B\to K^\ast e^+ e^-$ branching fractions in two dilepton invariant mass squared bins, which deviate from the Standard Model predictions by approximately $2.5\sigma$. These new…
We consider the flavor-changing decays of the Higgs boson in a grand unified theory framework which is based on the SU(5) gauge group and implements the principle of minimal flavor violation. This allows us to explore the possibility of…
The measurement of the Cabibbo-favored semileptonic decay $\Lambda_c^+\rightarrow \Lambda \mu^+\nu_{\mu}$ is reported using $4.5~\mathrm{fb}^{-1}$ of $e^+e^-$ annihilation data collected at center-of-mass energies ranging from 4.600~GeV to…
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,…
We present Standard Model predictions for lepton flavour universality ratios of inclusive $B\to X_{(c)} \ell \bar\nu_\ell$. For the $\ell=\mu,e$, these ratios are very close to unity as expected. For the $\tau$ mode, we update the SM…
The ratio of branching ratios of the $W$ boson to muons and electrons, $R^{\mu/e}_W=B(W\rightarrow \mu\nu)/B(W\rightarrow e\nu)$, has been measured using 140 fb$^{-1}$ of $pp$ collision data at $\sqrt{s}=13$ TeV collected with the ATLAS…
Here we update the predictions for lepton flavour violating tau and muon decays, $l_j \to l_i \gamma$, $l_j \to 3 l_i$, and $\mu-e$ conversion in nuclei. We work within a SUSY-seesaw context where the particle content of the Minimal…
LHCb reported anomalies in $B\to K^* \mu^+\mu^-$, $B_s\to\phi\mu^+\mu^-$ and $R(K)=B\to K \mu^+\mu^-/B\to K e^+e^-$. Furthermore, BaBar, BELLE and LHCb found hints for the violation of lepton flavour universality violation in…
There has been a steady interest in flavor anomalies and their global fits as ideal probes of new physics. If the anomalies are real, one promising explanation is a new $Z'$ gauge boson with flavor-changing coupling to bottom and strange…
The observed pattern of neutrino mixing may be the result of a 2-3($ \mu- \tau$) symmetry in the leptonic sector. We consider a two Higgs doublet model with a 2-3 symmetry in the down type quark and the charged lepton sector. The breaking…
Flavour-changing neutral-current processes, such as $b\to s \ell^+\ell^-$, are forbidden at tree level in the Standard Model and hence might receive comparatively large corrections from new particles. This document highlights recent…
We study the implications of an approximate $U(2)^5$ flavor symmetry at the TeV scale, under the assumption of new physics predominantly coupled to the third-generation fermions, focusing on the breaking of the $U(2)_\ell$ subgroup…
The discrepancies between $b\to s\ell^+\ell^-$ data and the corresponding Standard Model predictions point to the existence of new physics with a significance at the $5\sigma$ level. While previously a lepton flavour universality violating…
A direct search for lepton flavour violating decays of the Higgs boson (H) in the H to e tau and H to e mu channels is described. The data sample used in the search was collected in proton-proton collisions at sqrt(s) = 8 TeV with the CMS…
The long persistent discrepancies in $b\,\to\,s\, \ell\, \ell$ quark level transitions continue to be the ideal platform for an indirect search of new physics that lies beyond the SM. The measurements of $R_K$, $R_{K^*}$, $P_5^{\prime}$,…
Recently, the LHCb and CDF collaborations reported the measure of an unexpectedly large direct CP asymmetry in D meson decays. In this paper we ask if new physics associated with Partial Compositeness could plausibly explain this result. We…
The long-standing anomaly in the anomalous magnetic moment of the muon indicates the presence of chirality violating new physics contributions. A possible solution involves scalar leptoquarks with left- and right-handed couplings to the top…