相关论文: Tensions and correlations in $|V_{cb}|$ determinat…

The $\Lambda$CDM model provides a good fit to most astronomical observations but harbors large areas of phenomenology and ignorance. With the improvements in the precision and number of observations, discrepancies between key cosmological…

We discuss the present status of global fits to the CKM unitary triangle using the latest experimental and theoretical constraints. For the required nonperturbative weak matrix elements, we use three-flavor lattice QCD averages from…

We propose a new intuitive metric for evaluating the tension between two experiments, and apply it to several data sets. While our metric is non-optimal, if evidence of tension is detected, this evidence is robust and easy to interpret.…

We present a method for parametrizing heavy meson semileptonic form factors using dispersion relations, and from it produce a two-parameter description of the B -> B elastic form factor. We use heavy quark symmetry to relate this function…

The rare $B \to K^{(*)} \bar{\ell} \ell$ decays exhibit a long-standing tension with Standard Model (SM) predictions, which can be attributed to a lepton-universal short-distance $b \to s \bar{\ell} \ell$ interaction. We present two novel…

We determine the weak coupling |Vcb| between the b and c quarks using a sample of 3 million BB-bar events in the CLEO detector at the Cornell Electron Storage Ring. We determine the yield of reconstructed B --> D* l nu decays as a function…

We use recent Belle results on $\bar{B}^0\rightarrow D^{*+}l^-\bar{\nu}_l$ decays to extract the CKM element $|V_{cb}|$ with two different but well-founded parameterizations of the form factors. We show that the CLN and BGL…

We investigate the semi-leptonic decays of $\bar B \to D^{(*)} \ell\bar\nu$ in terms of the Heavy-Quark-Effective-Theory (HQET) parameterization for the form factors, which is described with the heavy quark expansion up to $\mathcal…

More precise extractions on the two important CKM matrix elements $|V_{cb}|$ and $|V_{ub}|$ are presented up to $1/m_Q^2$ corrections based on the complete heavy quark effective field theory (HQEFT) of QCD. The HQEFT as a large component…

In order to determine the ratio of CKM matrix elements |V_{ub}/V_{cb}| (and |V_{ub}|), we propose a new model-independent method based on the heavy quark effective theory, which is theoretically described by the phase space factor and the…

Current methods of determining V_ub are dominated by theoretical uncertainties. We present Monte Carlo simulations of three promising methods of determining V_ub with small theoretical and experimental errors. We find that with data samples…

We study the exclusive semileptonic $B$-meson decays $B\to K(\pi)\ell^+\ell^-$, $B\to K(\pi)\nu\bar\nu$, and $B\to\pi\tau\nu$, computing observables in the Standard model using the recent lattice-QCD results for the underlying form factors…

$B$ decays proceeding via $b\to c\ell\nu$ transitions with $\ell=e$ or $\mu$ are tree-level processes in the Standard Model. They are used to measure the CKM element $V_{cb}$, as such forming an important ingredient in the determination of…

We present the first determination of $V_{cb}$ from inclusive $B\to X_c \ell \bar\nu_\ell$ using moments of the dilepton invariant mass, $q^2$. These moments are reparametrization invariant quantities and depend on a reduced set of…

The values of the Hubble constant ($\rm{H_0}$) inferred from the cosmic microwave background (CMB) and local measurements via the distance ladder exhibit a $\sim5\sigma$ tension. In this work we propose that the tension might be partially…

Verifying $V_{tb} \simeq 1$ is critical to test the three generation assumption of the Standard Model. So far our best knowledge of $V_{tb}$ is inferred either from the $3\times 3$ unitarity of CKM matrix or from single top-quark…

A mini-review of measurements of inclusive semileptonic $B \to X_c\ell\nu$ and radiative $B\to X_s\gamma$ decays is presented. The semileptonic $X_c$ mass moments are presented from Belle and BABAR. The inclusive $B\to X_s\gamma$ gamma…

We examine the possibility for precise determination of |V_{ts}| (and |V_{td}/V_{ts}|) from the exclusive decays, $B --> K \ell^+ \ell^-, B --> K^* \ell^+ \ell^-$ (and $B --> \pi \ell^+ \ell^-, B --> \rho \ell^+ \ell^-$). We show that the…

The description of large-recoil heavy-to-light meson form factors is reviewed in the framework of soft-collinear effective theory. At leading power in the heavy quark expansion, three classes of approximate symmetry relations arise. The…

For a long time there have been active discussions about the sizable differences between $|V_{ub}|_{\rm incl}$ \& $|V_{ub}|_{\rm excl}$. However, the real $|V_{ub}|_{\rm incl}$ might be smaller than usually stated. The connection of the…