相关论文: Determination of |Vub|
A new method for a precision measurement of the CKM matrix element |Vub| is discussed, which combines good theoretical control with high efficiency and a powerful discrimination against charm background. The resulting combined theoretical…
The determination of the Vub element of the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix plays a central role in testing the Standard Model (SM) interpretation of CP violation. Measurements at B-Factories are contributing with…
The magnitude of the CKM matrix element Vub is determined by measuring the inclusive charmless semileptonic branching fraction of beauty hadrons at OPAL based on b -> Xu l nu event topology and kinematics. This analysis uses OPAL data…
We present a determination of the CKM matrix element |Vub| based on the analysis of semileptonic B decays from a sample of 88 million Upsilon(4S) decays collected with the BABAR detector at the PEP-II e+e- storage ring. Charmless…
We present a measurement of the branching fraction for the rare decays B->rho e nu and extract a value for the magnitude of Vub, one of the smallest elements of the Cabibbo-Kobayashi-Maskawa quark-mixing matrix. The results are given for…
The present status of our knowledge of the magnitude of the quark mixing parameter Vcb is reviewed, with particular emphasis on the factors affecting experimental and theoretical errors and on prospects for a more precise determination.
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…
It has been proposed to determine the CKM matrix element |V_ub| in a model-independent way from a combination of rare and semileptonic B and D decays near the zero recoil point. An essential ingredient in such a determination is a heavy…
The current status of the determinations of the CKM elements Vub and Vcb is reviewed and future prospects are discussed.
The ratio of the CKM quark-mixing matrix elements |Vub|/|Vcb| has been measured using B hadron semileptonic decays. The analysis uses the reconstructed mass M_X of the secondary hadronic system produced in association with an identified…
Recent results on inclusive and exclusive semileptonic B decays from B-factories are presented. The impact of these measurements on the determination of the CKM matrix elements |Vub| and |Vcb| is discussed.
We present a preliminary determination of the CKM matrix element |Vub| based on the analysis of semileptonic B decays from a sample of 88 million Upsilon(4S) decays collected with the BaBar detector at the e+e- storage ring. Charmless…
In Standard Model, CP violation arises from an irreducible complex phase in the quark mixing matrix, now under the name Cabibbo-Kobayashi-Maskawa matrix. This description has shown remarkably overall agreement with various experimental…
We review the theory of the determination of the CKM elements Vcb and Vub. Particular attention is paid to the determination of Vcb through inclusive semileptonic B decays to charm using a moment analysis, since this has shown most progress…
We present a new method for the determination of the Cabibbo-Kobayashi-Maskawa quark mixing matrix element $|V_{tb}|$ from electroweak loop corrections, in particular those affecting the process $Z\to b\bar{b}$. From a combined analysis of…
The CKM matrix elements $V_{td}$, $V_{ts}$ and $V_{tb}$, while notoriously hard to measure directly in experiment, can be determined to great precision within the Standard Model (SM) with a minimal set of observables due to unitarity of…
Using BaBar measurements of the inclusive electron spectrum in B->X_u e nu decays and the inclusive photon spectrum in B->X_s gamma decays, we extract the magnitude of the CKM matrix element Vub. The extraction is based on theoretical…
An overview of experimental determinations of different CKM elements is given with an emphasis on |Vub| and |Vcb| extraction. Measurements are compared to the Standard Model predictions and constraints on the unitarity triangle, arising…
We present a determination of the CKM parameter |Vus| based on new measurements of the six largest KL branching fractions and semileptonic form factors by the KTeV (E832) experiment at Fermilab. We find |Vus| = 0.2252 +- 0.0008(KTeV) +-…
The matrix element Vud of the CKM matrix can be determined by two independent measurements on neutron decay: the neutron lifetime tau and the ratio of coupling constants lambda, which is most precisely determined by measurements of the beta…