Related papers: Rare radiative leptonic B-decays
Recently, the Belle II Collaboration reported the branching fraction $\mathcal{B}(B^+ \to K^+ \nu \bar{\nu})=(2.3\pm0.7)\times10^{-5}$ with a significance of $3.5\sigma$, which is $2.7\sigma$ above the SM expectation. Motivated by this…
We calculate, for the first time using unquenched lattice QCD, form factors for the rare decay B -> Kll in and beyond the Standard Model. Our lattice QCD calculation utilizes a nonrelativistic QCD formulation for the b valence quarks, the…
Employing the QCD factorization formalism we compute $B_{u}^{-} \to \gamma^{\ast} \, \ell \, \bar \nu_{\ell}$ form factors with an off-shell photon state possessing the virtuality of order $m_b \, \Lambda_{\rm QCD}$ and $m_b^2$,…
Motivated by the first search for the rare charged-current $B$ decay to four leptons, $\ell \bar{\nu}_\ell \ell^{(\prime)} \bar{\ell}^{(\prime)}$, we calculate the decay amplitude with factorization methods. We obtain the $B\to \gamma^*$…
We estimate the contributions of higher K-resonances to the radiative rare decays b -> s gamma. We use the spin symmetry for heavy quarks to reduce the number of independent form factors to four Isgur-Wise functions, which are estimated…
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…
We calculate the differential branching fraction, lepton forward-backward asymmetry and direct CP asymmetry for $B_{d,s}\to\gamma\ell\bar{\ell}$ decays with an energetic photon. We employ factorization methods, which result in rigorous…
In the framework of the top triangle moose $(TTM)$ model, we analyze the rare decays $\Lambda_{b}\rightarrow \Lambda l^{+}l^{-} (l=e,\mu,\tau)$ by using the form factors calculated in full $QCD$. We calculate the contributions of the new…
Using 20.3$~\rm fb^{-1}$ of $e^+e^-$ annihilation data collected at a center-of-mass energy of 3.773$~\rm GeV$ with the BESIII detector, we report an improved search for the radiative leptonic decay $D^+\to\gamma e^+\nu_e$. An upper limit…
We calculate the contribution of the weak annihilation to the $B\rightarrow \rho\gamma$ decay amplitude by means of QCD sum rules using the photon light-cone wave function. We find that this long-distance contribution amounts to about 10\%…
We study the decays of $B_{s,d} \to l^+ l^- \gamma (l=e, \mu,\tau)$ within the light-front model. We calculate the tensor type form factors and use these form factors to evaluate the decay branching ratios. We find that, in the standard…
We discuss exclusive radiative decays in QCD factorization within the Standard Model. In particular, we consider the decays B -> V gamma, with a vector meson K* or rho in the final state, and the double radiative modes B_s -> gamma gamma…
We study the structure-dependent contributions to the radiative baryonic $B$ decays of $B \to {\bf B}{\bf \bar B'}\gamma$ in the standard model. We show that the decay branching ratios of $Br(B \to {\bf B}{\bf \bar B'}\gamma)$ are…
We study some rare decays of $B$ meson involving the quark level transition $b \to q l^+l^- (q=d,s)$ in the scalar leptoquark model. We constrain the leptoquark parameter space using the recently measured branching ratios of $B_{s,d} \to…
This study examines the properties of heavy quarkonia $X$ by treating them as bound states of $Q$ and $\bar{Q}$ at the LO level within the NRQCD framework, where $Q$ represents either a charm or a bottom quark. The branching ratios for the…
We make use of the information obtained from semileptonic decays of $B$ and $D$ mesons, within an effective lagrangian description based on heavy quark theory and on chiral expansion, to study the radiative decays $B \to K^\star \gamma$ and…
We present the first complete results for the semileptonic and rare radiative form factors of B-mesons weak decay into a light vector-meson (rho, omega, K*, phi) in the light-cone sum-rule approach. The calculation includes radiative…
The rare decays $B_{(s,d)}^*\to l^+ l^-$ are important to probe the flavour sector of the standard model and to search new physics beyond the SM. Unlike pseudoscalar B meson, the leptonic decays of vector $ B_(s,d)^*$ mesons are not…
I give an overview of the QCD sum rule predictions for the form factors of B-meson weak decays to light hadrons (and leptons)
We study the decay $B_c \rightarrow D_s^* \gamma$. There are two mechanisms contributing to the process. One proceeds through the short distance $b{\rightarrow}s\gamma$ transition and the other occurs through weak annihilation accompanied…