Related papers: Constraining New Physics with D meson decays
Recently hints of lepton flavor non-universality emerged when the BaBar Collaboration observed deviations from the standard model predictions in $R(D^{(*)}) \equiv {\cal B}({\bar B} \to D^{(*)+} \tau^- {\bar\nu}_\tau) / {\cal B}({\bar B}…
Recently LHCb has measured the branching ratio of the rare decay of $B_s^0\rightarrow \mu^+ \mu^- $ as $2.9^{+1.1}_{-1.0} \times10^{-9}$ which is at par with the predicted standard model (SM) value. This result does not predict the absence…
We investigate the potential of rare hyperon decays to probe the short distance structure in the $s\to d\nu\bar\nu$ and $s\to d\ell^+\ell^-$ transitions. Hyperon decays into neutrinos ($B_1\to B_2\nu\bar\nu$) can be reliably predicted by…
The $\Delta S = 2$ $b \to \bar d ss$ transition proceeds via the box - diagram in the Standard Model with a branching ratio calculated to be below $10^{-11}$, thus providing an appropriate testing ground for physics beyond the Standard…
We perform a global analysis of the $b\to c\tau\nu$ data using the recent lattice results on the $B_c\to J/\psi$ vector and axial-vector form factors. To explore the effects from the tensor operator of new physics beyond the standard model,…
Motivated by renewed evidence for new physics in $b \to s\ell\ell$ transitions in the form of LHCb's new measurements of theoretically clean lepton-universality ratios and the purely leptonic $B_s\to\mu^+\mu^-$ decay, we quantify the…
The current world averages of the ratios $R_{D^{(*)}}$ are about $4\sigma$ away from their Standard Model prediction. These measurements indicate towards the violation of lepton flavor universality in $b\rightarrow c\,l\,\bar{\nu}$ decay.…
We analyze the branching ratios of B to D(*) + Ds0*(Ds1) decays using the factorization hypothesis. The B to D(*) transition form factors are taken from a model-independent analysis done by Caprini, Lellouch and Neubert based on heavy quark…
The BaBar, Belle, and LHCb collaborations have reported evidence for new physics in $B\to D\tau\nu$ and $B\to D^*\tau\nu$ of approximately $3.8\sigma$. There is also the long lasting discrepancy of about $3\sigma$ in the anomalous magnetic…
The general analysis of lepton polarization asymmetries in rare B -> K^* l^+ l^- decay is investigated. Using the most general, model independent effective Hamiltonian, the general expressions of the longitudinal, normal and transversal…
The LHCb collaboration has very recently released a new study of $B^+ \to K^{+} \ell^+ \ell^-$ and $B \to K^{*0} \ell^+ \ell^-$ ($\ell = e,\mu$) decays, testing lepton universality with unprecedented accuracy using the whole Run 1 and 2…
We propose a class of left-right symmetric models (LRSMs) with spontaneous D parity breaking, where SU(2)_R breaks at the TeV scale while discrete left-right symmetry breaks around 10^9 GeV. By embedding this framework in a…
We have obtained the differential decay rate and calculated the branching ratios of the exclusive semileptonic decays $B(D) \to Xl\nu$, where $X$ is a p-wave meson, using the nonrelativistic ISGW quark model. Our results are compared with…
The ratio of branching ratios in leptonic pion decay $R_{\pi} \equiv (\Gamma(\pi^- \to e \nu_e))/(\Gamma(\pi^- \to \mu \nu_\mu))$ is a powerfully sensitive probe of new interactions beyond the electroweak standard model. This is due to the…
We present a systematic lattice calculation of the $D_s \to \phi \ell \nu_\ell$ semileptonic decay using (2+1)-flavor Wilson-clover fermion configurations generated by the CLQCD collaboration. Seven gauge ensembles with different lattice…
In this talk an analysis of the rare exclusive $B$ decays $B\to K\nu\bar\nu$ and $B\to K^{*}\nu\bar\nu$ within and beyond the Standard Model is presented. Combining new form factor determinations from lattice QCD with light-cone sum rule…
Motivated by the anomalies present in $b \to s\,l^+\,l^-$ neutral current decays, we study the corresponding $B_c \to (D_s,\,D^{\ast}_s)\mu^+\mu^-$ decays within the standard model and beyond. We use a model independent effective theory…
Recent measurements of exclusive $B^{-} \to \tau^{-}\,\nu$ and $B^0 \to \pi^{+}\,l^{-}\,\bar{\nu}_l$ decays via the $b \to u\,l\,\nu$ transition process differ from the standard model expectation and, if they persist in future $B$…
A search for physics beyond the standard model (SM) in the final state with a hadronically decaying tau lepton and a neutrino is presented. This analysis is based on data recorded by the CMS experiment from proton-proton collisions at a…
Leptonic and semi-leptonic $D$ decays at BESIII contribute the most precise experimental measurement of $|V_{cs(d)}|$ and form factor $f_{D_{(s)}}$ in the world based on 2.93 fb$^{-1}$ and 3.19 fb$^{-1}$ data taken at center-of-mass…