相关论文: The Exclusive Decay $B\to\rho e \nu$ Beyond Model …
A new technique is discussed that can be applied to $\Lambda_b^0$ baryon decays where decays with one missing particle can be discerned from background and their branching fractions determined, along with other properties of the decays.…
To extract the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $|V_{ub}|$, we have re-analyzed all the available inputs (data and theory) on the $B\to\pi l\nu$ decays including the newly available inputs on the form-factors from light cone…
I give a brief introduction to the scope of lattice QCD calculations in our effort to extract the fundamental parameters of the standard model. This goal is illustrated by two examples. First I discuss the extraction of CKM matrix elements…
We study the rare decays $B_s^0\to D^\pm \pi^\mp$ and $\bar B_s^0\to D^\mp \pi^\pm$, which can occur only via annihilation type $W$ exchange diagrams in the standard model. The time-dependent decay rates of the four channels can provide…
The photoleptonic decay $B^-\to \gamma \ell^-\bar{\nu}$ is the simplest low-energy process that probes the substructure of the $B$ meson, making it an excellent candidate to determine the parameters of $B$-meson light-cone distribution…
We use loop induced processes like meson oscillations and rare b hadron decays to determine the absolute values of the CKM matrix elements $|V_{ub}|$ and $|V_{cb}|$ and compare our results to the standard determinations based on inclusive…
We present a determination of the magnitude of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $V_{cb}$ using $B\to D\ell\nu$ decays. The result is based on $e^+e^-\to\Upsilon(4S)$ data recorded by the Belle II detector corresponding to…
Hadronic form factors for the rare weak transitions $\Lambda_{b}\rightarrow\Lambda^{(*)}$ are calculated using a nonrelativistic quark model. The form factors are extracted in two ways. An analytic extraction using single component wave…
We use three-point QCD sum rules to calculate the form factors governing the rare exclusive decays B \to (K,K^*) \ell^+ \ell^-, B \to (K,K^*) \nu \bar\nu. We predict the branching ratios, the invariant mass distributions of the lepton pair…
Taking into account the $\Lambda$ baryon distribution amplitudes and the most general form of the interpolating current of the $\Lambda_{b}$, the semileptonic $\Lambda_{b}\rar \Lambda \ell^+\ell^- $ transition is investigated in the…
We report the first lattice QCD calculation of the form factors for the standard model tree-level decay $B_s\to K \ell\nu$. In combination with future measurement, this calculation will provide an alternative exclusive semileptonic…
We present a combined measurement of the Cabibbo-Kobayashi-Maskawa matrix element |V_{cb}| and of the parameters rho^2, R_1(1), and R_2(1), which fully characterize the form factors for the B0 -> D*- l+ nu_l decay in the framework of…
We derive a set of light-cone sum rules relating the $S$-wave $B\to K \pi$ hadronic form factors to the $B$-meson light-cone distribution amplitudes (LCDAs), taking into account the complete set of LCDAs up to and including twist four.…
I discuss QCD sum rules determinations of the form factors governing the decay $B \to \pi (\rho) \ell \nu$. For some of these form factors the computed dependence on the momentum transferred does not agree with the expectation from the…
As part of a study BSM corrections to leptonic decays of the $B_c$ meson, Tran et al. (arXiv:1801.06927) use the covariant confining quark model (CCQM) to estimate the matrix element of the pseudo-scalar curent between the vacuum and the…
The rare decay B --> K* mu+ mu- is considered to be a golden channel for LHCb, as the polarization of the K* allows a precise angular reconstruction resulting in many observables that offer new important tests of the Standard Model and its…
Applications of QCD sum rules to exclusive decays of heavy mesons are reviewed. In detail, we discuss the calculations of the B and $D$ decay constants, the heavy-to-light form factors $f^+(p^2)$ and $f^0(p^2)$, and the strong couplings…
We report on the current status of semi-leptonic $B_{(s)}$ decays, including rare decays, and the extraction of the absolute values of the CKM matrix elements $|V_{cb}|$ and $|V_{ub}|$.
Exclusive semileptonic $b$ hadron decays ($b \to u \ell \nu$) serve as a sandbox for probing strong and electroweak interactions and for extracting the CKM element $V_{ub}$. Instead, this work investigates their underexplored potential to…
An explicit model is presented which gives the momentum transfer-dependent ratios of form factors of hadronic currents. For the unknown Isgur-Wise function and its generalization for transitions to light particles a simple phenomenological…