相关论文: Measurement of $V_{ub}$

I report B physics results from the CLEO collaboration, highlighting measurements of the Cabibbo-Kobayashi-Maskawa matrix elements |Vcb| and |Vub|. I report a recent measurement of |Vub| through study of the q^2 dependence of B -> pi l nu…

I present a brief overview of the measurements of exclusive B -> X_u l nu transitions, with a focus on issues facing robust averaging of branching fractions and |Vub| from current and anticipated measurements.

I review currently discussed methods to determine the CKM mixing matrix element $|V_{ub}|$ from experimental data. Although the theory of inclusive decays and their spectra has entered a model-independent stage, its predictions are still…

We have extracted the ratio $|V_{ub}|/|V_{cb}|$ from a combined study of the available inputs on $\bar{B}\to (\pi,\rho,\omega)\ell^- \bar{\nu}_{\ell}$ and $\bar{B}(\bar{B}_s)\to (D^{(\ast)}, D_s^{(\ast)})\ell^- \bar{\nu}_{\ell}$ ($\ell =…

The CLEO Collaboration has extracted improved values of |V_cb| and |V_ub| from measurements of exclusive and inclusive decays of B mesons. The measurement of B -> D* ell nu at zero recoil combined with the predicted form factor F_D*(w_min)…

We discuss a simple approach to measure the weak mixing angles phi_s and phi_d of the Bs and Bd systems in the presence of New Physics. We present a new expression that allows one to measure directly the New Physics mixing angles if New…

We present a measurement of $|V_{ub}|$ from a simultaneous study of the charmless semileptonic decays $B^0\to\pi^- \ell^+ \nu_{\ell}$ and $B^+\to\rho^0 \ell^+\nu_{\ell}$, where $\ell = e, \mu$. This measurement uses a data sample of 387…

The semileptonic $B$ meson decays of the type $B \to X_u \ell \nu$ are important for measuring the magnitude of the CKM matrix element $V_{ub}$. Recent measurements of inclusive $B \to X_u e \nu_e$ and hadronically tagged $B^0 \to \pi^-…

We report a new measurement of the CKM parameter V_ub made with a sample of 9.7 million B B-bar events collected with the CLEO II detector. Using Heavy Quark theory, we combine the observed yield of leptons from semileptonic B decay in the…

I present recent CLEO measurements of inclusive semileptonic B decay spectra and the branching fraction. I also report preliminary results from a combined fit to spectral moments, which are compared to expectations in the Heavy Quark…

A preliminary analysis of exclusive $\btou$ decays to the final states $\pi^\pm\ell\nu$, $\pi^0\ell\nu$, $\rho^\pm\ell\nu$, $\rho^0\ell\nu$\ and $\omega\ell\nu$ based on $2.2\e{6}$ $\bbar$ decays collected at CLEO is presented. We have…

I report results from the CLEO collaboration on semileptonic B decays, highlighting measurements of the Cabibbo-Kobayashi-Maskawa matrix elements Vcb and Vub. I describe the techniques used to obtain the recent improvements in precision for…

A new measurement of $B_{\pi e2}$, the $\pi^+ \to e^+\nu(\gamma)$ decay branching ratio, is currently under way at the Paul Scherrer Institute. The present experimental result on $B_{\pi e2}$ constitutes the most accurate test of lepton…

Measurements of the angles and sides of the unitarity triangle and of the rates of rare B meson decays are crucial for the precise determination of Standard Model parameters and are sensitive to the presence of new physics particles in the…

We present two recent measurements of semileptonic B decays at Belle, offering valuable insights into the determination of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $|V_{ub}|$. These analyses use the full Belle dataset, comprising…

The experimental status of the Cabibbo-Kobayashi-Maskawa matrix is reviewed. Measurements discussed include B0_(s)-\bar{B}0_(s) mixing and several rare B and K decays with implications for |V_td| and |V_ts|. Extraction of |V_cb| and |V_ub|…

We reemphasize the strong dependence of the branching ratios $B(K^+\to\pi^+\nu\bar\nu)$ and $B(K_L\to\pi^0\nu\bar\nu)$ on $|V_{cb}|$ that is stronger than in rare $B$ decays, in particular for $K_L\to\pi^0\nu\bar\nu$. Thereby the persistent…

We review the status of inclusive |Vub| measurements where many new results have become available recently.

Measurements of many Standard Model constants are clouded by uncertainties in nonperturbative QCD parameters that relate measurable quantities to the underlying parton-level processes. Generally these QCD parameters have been obtained from…

By analyzing B -> X_u l nu_l spectra with a model based on soft-gluon resummation and an analytic time-like QCD coupling, we obtain |V_ub| = (3.76 +-0.13 +- 0.22)*10^(-3), where the first and the second error refers to experimental and…