The identification of the distinctive flavour structure of the B anomalies revealed an interesting coincidence with the SM approximate flavour symmetry i.e. $U(2)^5$. The flavour non-universal Pati-Salam model, which unifies quarks and leptons, establishes the connection providing a combined explanation of the charged and neutral current B anomalies as well as of the mass hierarchies of the...
We investigate the effect of scalar leptoquark on the rare semileptonic $B \to K_1 ll$ decay mode. We constrain the leptoquark coupling by using the updated experimental limits on the branching ratios of $b \to s ll$ processe and the lepton nonuniversality $R_{K^{(*)}}$ parameters. Using the constrained new parameters, we estiamte the branching ratios, forward-backward asymmetry, lepton...
The radiative tau decay ($\tau^- \rightarrow \pi^- \nu_\tau \gamma$) involves two contributions: the Internal Bremmstrahlung (IB) contribution and the Structure dependent (SD) contribution. The SD contribution encodes the non-perturbative QCD effects and depends on two form factors ($F_A$ and $F_V$). Here, I will discuss the computation of these form factors in the framework of light cone sum...
The possibility of new physics in terms of lepton number violating (LNV) interactions is intriguing out of various reasons: LNV could be tightly linked to the generation of neutrino masses of Majorana nature while at the same time having direct implications for the generation of the baryon asymmetry of our Universe. The $K^+→π^+ν\bar{ν}$ decay is one of the most promising modes to search for...
CP violation in the third generation fermion Higgs couplings may play an important role in the electroweak baryogenesis, however it is strongly bounded by the experimental limits on the electron electric dipole moment. In the effective field theory framework to beyond the Standard Model physics, it can originate from dimension six operators. Under such assumptions like Minimal Flavour...
CP violation was first observed more than 50 years ago. Although its effect has been studied in meson decays for a long time, we still have no observation of CP violation in weakly decaying baryons. Baryons consisting of one or more heavy quarks, so called hyperons, $Y$, can be used to search for CP-violating mechanisms beyond the Standard Model. At the BESIII experiment in Beijing, strange...
A bottom-up approach has been adopted to identify a flavour model that agrees with present experimental measurements. The charged fermion mass hierarchies suggest that only the top Yukawa term should be present at the renormalisable level. Similarly, describing the lightness of the active neutrinos through the type-I Seesaw mechanism, right-handed neutrino mass terms should also be present at...
Recently the experimental data attained from the Belle, BABAR, and LHCb experiments, has shown the corporeality of anomalies in the fractions $ R(D)$and $R(D^*)$ coupled with the charged current transition $ b \to c \tau \bar{\nu_{\tau}}$. Also, we observed that lepton flavor universality can be examined through the ratio of leptonic $\Upsilon = \Upsilon(ns) (n=1,2,3)$ and $\psi$ quarkonia...
The first row of the Cabibbo-Cobayashi-Maskawa (CKM) matrix shows a discrepancy of $\sim 3\sigma$ with unitarity, known as the ”Cabibbo Angle Anomaly” (CAA). After reviewing the origin and status of the anomaly, I investigate the various possibilities to explain it in the context of physics beyond Standard Model (BSM) which can be broadly grouped into three categories: modifications of...
The first results from the Muon $g-2$ experiment at Fermilab have strengthened hints of exciting new physics in the leptonic sector. Among the different models that can account for this anomaly, the addition of a $U(1)_{L_\mu - L_\tau}$ gauge symmetry to the SM is a particularly elegant explanation, introducing a so-called hidden photon, but not requiring any additional fermionic content....
We identify the two scalar leptoquarks capable of generating sign-dependent contributions to leptonic magnetic moments, $R_2\sim (\mathbf{3}, \mathbf{2}, 7/6)$ and $S_1\sim (\mathbf{3}, \mathbf{1}, -1/3)$, as favoured by current measurements. We consider the case in which the electron and muon sectors are decoupled, and real-valued Yukawa couplings are specified using an up-type quark...
We explore the implications of g-2 new result to five models based on the SU(3)C×SU(3)L×U(1)N gauge symmetry and put our conclusions into perspective with LHC bounds. We show that previous conclusions found in the context of such models change if there are more than one heavy particle running in the loop. Moreover, having in mind the projected precision aimed by the g-2 experiment at FERMILAB,...
Experimentalists have long sought a method that allows them to control as they like the branching ratios of an unstable particle decay and direct some decay to follow one specific desired channel without another. The powerful laser could make this dream come true. In this work and within the framework of the standard electroweak model, we investigate theoretically the laser effect on the...
The latest results of beauty meson decays from LHCb are presented. This includes the latest time-integrated CP violation measurements with information on the (Kpi) puzzle and on the CKM angle gamma, and time-dependent CP violation measurements. In addition recent determinations of CKM elements, and the legacy result on Bs mixing will be presented
The $4.2\sigma$ deviation of the anomalous muon magnetic moment measurements recently performed at Fermilab with respect to the state of the art theory prediction has strengthened the motivation for standard model extensions. In this talk, we analyse a model involving an additional $Z_d$ mediator and we show the constraints obtained considering the muon and electron magnetic moment...
The NA62 experiment reports the branching ratio measurement BR(K+→π+νν) at 68% CL, based on the observation of 20 signal candidates with an expected background of 7.0 events from the total data sample collected at the CERN SPS during 2016-2018. This provides evidence for the very rare K+→π+νν decay, observed with a significance of 3.4σ. The experiment achieves a single event sensitivity of...
The flavour anomalies in the b->sll transition receive large attention. Apart from the recent update on lepton-flavour-universality, LHCb has new results on the rare decay Bs->mumu, angular distributions of charged B mesons decaying to K*mumu, and analyses of radiative and B decays to K*ee at low-q2, and on the Bs->Phimumu decay rate with full run-2 data.
BESIII has collected 2.9, 6.3 and 4.4 fb-1 of e+e- collision data samples at 3.773, 4.178-4.226 and 4.6-4.7 GeV, respectively. We report recent measurements of the (semi)leptonic decays D(s) -> l+nu (l=mu, tau) and D(s) -> X l+nu [X=K(*), rho, eta('), a_0, K_1, and l=e, mu]. The decay constants f_D(s), the semileptonic form factors f(0) and the CKM matrix elements |V_cs(d)| are determined...
In the recent years, several measurements of $B$-decays with flavor changing neutral currents, i.e. $b\to s$ transitions hint at deviations from the Standard Model (SM) predictions.These decays are forbidden at tree-level in the SM and can only proceed via suppressed loop level diagrams. Rare decays of $B$ mesons are an ideal probe to search for phenomena beyond the SM, since contributions...
The theoretical calculation for pseudo--scalars hadronic decays $P \to M a$, with the Axion-Like-Particle escaping
the detection, is reviewed. While one-loop penguin contributions are usually considered, tree-level processes have
most often been overlooked in literature. Following the Brodsky/Lepage approach the tree-level contribution to the
ALP pseudo--scalar decay is estimated....
Many extensions of the Standard Model include the possibility of light new particles, such as axions or dark matter candidates. These scenarios can be probed using the large data sets collected by 𝐵-factories, complementing measurements performed at the LHC. We report on a search for an Axion-like particle (ALP), 𝑎, produced in the Flavor-Changing Neutral-Current decay 𝐵→𝐾𝑎, with 𝑎→𝛾𝛾, which...
The Belle II experiment is a substantial upgrade of the Belle detector and will operate
at the SuperKEKB energy-asymmetric e+e− collider. The design luminosity of the machine
is 8 × 1035 cm−2s−1 and the Belle II experiment aims to record 50 ab−1 of data, a factor
of 50 more than its predecessor. From February to July 2018, the machine has completed a
commissioning run and main operation of...
The $BABAR$ detector collected a sample of 122 million $\Upsilon(3S)$ mesons, corresponding to an integrated luminosity of 28 ${\mathrm{fb^-1}}$, operating the PEP-II $e^+e^-$ collider at a center-of-mass energy of 10.355 ${\mathrm{GeV}}/c^2$. This sample is the largest ever collected at that energy and provides unique opportunities to test several aspects of the Standard Model (SM).
We...
We make a comprehensive study of vector-like fermionic dark matter and flavor anomalies in a simple extension of standard model. The model is added with doublet vector-like fermions, of quark and lepton type. An additional lepton type singlet fermion is included, whose admixture with vector-like lepton doublet is examined in relic density and direct detection perspective. Furthermore, two...