Related papers: |V_us| from Strange Hadronic Tau Data
A sum rule for determining |V_us| from a combination of hadronic tau decay and electroproduction data is discussed. Indications of problems with analogous, purely tau-decay-based analyses, most likely associated with slow convergence of the…
We study the success to describe hyperon semileptonic decays of four models that incorporate second-order SU(3) symmetry breaking corrections. The criteria to assess their success is by determining V_{us} in each of the three relevant…
Recent reports of the observation of the decay $\tau \rarrow \nu_{\tau} + K + \pi + \pi$ raise interesting questions. The $u-s$ quark mass difference can induce an effective second-class current in the strange sector and enhance decays to…
We present an analysis of the m_s^2-corrections to Cabibbo-suppressed tau lepton decays employing contour improved resummation within an effective scheme which is an essential new feature as compared to previous analyses. The whole…
We study the available data on exclusive leptonic and semileptonic $c\to s\ell^+\nu$ decays within the Standard Model and beyond. Our analysis accounts for theory correlations between the relevant hadronic matrix elements through…
We study the reliability of extractions of |V_{us}| based on flavor-breaking hadronic tau decay sum rules. The ``(0,0) spectral weight'', proposed previously as a favorable candidate for this extraction, is shown to produce results having…
Recent sum rule determinations of |V_us|, employing flavor-breaking combinations of hadronic tau decay data, are significantly lower than either expectations based on 3-family unitarity or determinations from K_ell3 and…
The precise determination of the CKM matrix element $\left| V_{cb}\right|$ is important for carrying out tests of the flavour sector of the Standard Model. In this article we present a preliminary analysis of the $\bar B^0 \to D^{*\,+} \,…
Recent experimental improvements on K-decay data allow for a precise extraction of the strangeness-changing scalar K pi form factor and the related strange scalar spectral function. On the basis of this scalar as well as the corresponding…
We update the determination of |V_us| using semielectronic and semimuonic decays of K mesons. A modest improvement of 15% with respect to its present value is obtained for the error bar of this matrix element when we combine the four…
A numerical error is pointed out in the existing expression for the order $\alpha_s^2$ longitudinal component of the squared-mass (D=2) contribution to the hadronic $\tau$ decay rate. The corrected version is found to be such that, to order…
Due to its comparatively theoretical ``simplicity'', the decay channel $B\to\rho e \nu$ offers one of the best possibilities to determine the CKM matrix element $|V_{ub}|$ accurately. I present a new calculation of the relevant hadronic…
We determine the Cabibbo-Kobayashi-Maskawa matrix (CKM) element |Vus| in several different ways using updated preliminary HFAG averages for the tau lepton branching fractions and we compare the results with the determinations obtained from…
In this work radiative corrections in the total hadronic decay rate of the tau-lepton and some moments of its differential distributions are studied employing perturbative QCD and the operator product expansion. We calculate quadratic quark…
Using HISQ $N_f=2+1+1$ MILC ensembles with five different values of the lattice spacing, including four ensembles with physical quark masses, we have performed the most precise computation to date of the $K\to\pi\ell\nu$ vector form factor…
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…
Hadronic decays of the $\tau$ lepton provide a clean source to study hadron dynamics in an energy regime dominated by resonances, with the interesting information captured in the spectral functions. Recent results on exclusive channels are…
Tau lepton decays with open strangeness in the final state are measured with the OPAL detector at LEP to determine the strange hadronic spectral function of the tau lepton. The decays T- ->(Kpi)-nu tau, (Kpipi)-nu tau and (Kpipipi) -nu tau…
The more precise extraction for the CKM matrix element |V_{cb}| in the heavy quark effective field theory (HQEFT) of QCD is studied from both exclusive and inclusive semileptonic B decays. The values of relevant nonperturbative parameters…
Three important QCD-related aspects of the $\tau$ and $\mu$ dynamics are reviewed: the determination of the strong coupling from the hadronic tau decay width, leading to the updated value $\alpha_s(m_\tau^2) = 0.331 \pm 0.013$; the…