Related papers: $b\to{}s\ell\ell$ decays at LHCb
Motivated by the LHCb measurement of the hyperon decay mode $\Sigma^+\to p\mu^+\mu^-$ and prospects for improvement, we revisit the estimates for the rate and muon forward-backward asymmetry within the standard model and beyond. The…
We study the rare decays of $B_{s} \to M_s\ell \bar{\ell}$ ($M_s=\eta, \eta',\phi$ and $\ell=\nu,e,\mu,\tau$) in the standard model. With the hadronic form factors evaluated in the light front and constituent quark models, we estimate the…
Some of the recent measurements in the neutral current sector $b\rightarrow s l^+l^-$ ($l=e$ or $\mu$) as well as in the charged current sector $b \rightarrow c \tau \bar{\nu}$ show significant deviations from their Standard Model…
We are reporting on a search for flavour-changing neutral current decays $D^0 \to \mu^+ \mu^-$ and $D^0 \to e^+ e^-$, and for lepton-flavour violating decays $D^0 \to e^\pm \mu^\mp$, the measurement of $D^+_{(s)} \to K_S^0 \pi^+$ and…
We present HPQCD's improved scalar, vector and tensor form factors for $B \to K$ semileptonic decays, using the heavy-HISQ formalism for more accurate normalisation of the weak currents. Working with masses close to the physical $b$ on the…
Several experiments observed deviations from the Standard Model (SM) in the flavour sector: LHCb found a $4-5\,\sigma$ discrepancy compared to the SM in $b\to s\mu^+\mu^-$ transitions (recently supported by an Belle analysis) and CMS…
Charged lepton flavor violation is forbidden in the Standard Model but possible in several new physics scenarios. In many of these models, the radiative decays $\tau^{\pm}\rightarrow\ell^{\pm}\gamma$ ($\ell=e,\mu$) are predicted to have a…
Some selected topics in flavour changing neutral current processes in $B$ decays are discussed in the context of the Standard Model. The emphasis here is on the determination of the CKM matrix elements from the ongoing and forthcoming…
We model-independently analyze the angular distributions of B -> K ll decays, l = e, mu, for low dilepton mass using QCD factorization. Besides the decay rate, we study the forward-backward asymmetry A_FB^l and a further observable, F_H^l,…
The Standard Model of particle physics predicts that charged leptons have the same electroweak interaction strength. This symmetry, called lepton flavour universality, was found to hold in a wide range of particle decays. One observable…
Flavour changing neutral current (FCNC) transitions $c\to u\gamma$ and $c\to ul^+l^-$ are very rare in the standard model and present an interesting probe for the physics beyond it. We study long distance contamination to these short…
The Belle-II experiment has recently measured $\mathcal{B}(B^+\to K^+\nu\bar{\nu})$, which appears to be almost $3\sigma$ larger than its Standard Model (SM) prediction. In this talk, I will critically revisit the status of the SM…
Recent measurements of the lepton flavor universality ratios $R^{\mu e}_{K}$ and $R^{\mu e}_{K^*}$ in $B\to \left(K, K^*\right)\mu^{+}\mu^{-}\left(e^+e^-\right)$ at LHCb align with the Standard Model predictions, necessitating search for…
Lepton flavor universality in the Standard Model and hints of its violation in neutral ($R_K$) and charged currents $(R_{D^{(*)}})$ in $B$ decays are presented. We discuss model independent features as well as several leptoquark scenarios…
The flavor changing neutral current decays $t\to c X$ ($X=\gamma,\,g,\, Z,\, H$) and $t\to c\bar \ell\ell $ ($\ell=\mu,\,\tau$) are studied in a renormalizable scalar leptoquark (LQ) model with no proton decay, where a scalar $SU(2)$…
A search for $B^{+} \to D_s^{+}K^{+}K^{-}$ decays is performed using $pp$ collision data corresponding to an integrated luminosity of 4.8 fb$^{-1}$, collected at centre-of-mass energies of 7, 8 and 13$\,$TeV with the LHCb experiment. A…
The flavor-changing neutral current decay B_s->mu mu is highly suppressed in the standard model, but its branching fraction of 3.4*10^-9 could be significantly enhanced through contributions from new physics. At the LHC, this rare decay…
The ability of present and future experiments to test the Standard Model in the $B$ meson sector is described. We examine the loop effects of new interactions in flavor changing neutral current $B$ decays and in $Z\to b\bar b$,…
We perform an analysis of the consequences of various new physics operators on the lepton flavor violating (LFV) decay modes mediated through $b \to s \ell _1 \ell _2$ transitions. We scrutinize the imprints of the (pseudo)scalar and…
The semi-leptonic baryonic $b\to s$ decay, $\Lambda_b\rightarrow \Lambda \ell^+\ell^-$, has been studied and new angular observables and asymmetries have been proposed which can test the presence of new physics beyond the standard model.