Related papers: Extraction of m_s and |V_us| from Hadronic Tau Dec…
The recent update of the strange spectral function and the moments of the invariant mass distribution by the OPAL collaboration from hadronic tau decay data are employed to determine |V_us| as well as m_s. Our result,…
Recent experimental results on hadronic tau decays into strange particles by the OPAL collaboration are employed to determine V_us and m_s from moments of the invariant mass distribution. Our results are V_us = 0.2208+-0.0034 and m_s(2 GeV)…
Recent progress in the determination of |V_us| employing strange hadronic tau-decay data are reported. This includes using the recent OPAL update of the strange spectral function, as well as augmenting the dimension-two perturbative…
The mass of the strange quark is determined from SU(3)-breaking effects in the tau hadronic width. Compared to previous analyses, the contributions from scalar and pseudoscalar spectral functions, which suffer from large perturbative…
We report on recent work to determine the CKM matrix element |V_{us}| using strange hadronic \tau decay data. We use the recent OPAL update of the strange spectral function, while on the theory side we update the dimension-two perturbative…
Already in the past, hadronic tau decays have served as an interesting source to obtain information on the parameters of the Standard Model, like the strong coupling alpha_s or the strange quark mass. Below it will be shown that the…
We discuss the simultaneous determination of m_s and V_us from flavor-breaking hadronic tau decay sum rules, focussing on weight choices designed to better control problems associated with the slow convergence of the relevant integrated D=2…
Quark mass corrections to the tau hadronic width play a significant role only for the strange quark, hence providing a method for determining its mass. The experimental input is the vector plus axial-vector strange spectral function derived…
We study the simultaneous determination of m_s and V_us from flavor-breaking hadronic tau decay sum rules using weights designed to bring under better control problems associated with the slow convergence of the relevant D=2 OPE series.…
We discuss the ratio of hadronic to leptonic tau-decays, that can be expanded in an operator product expansion. The sensitivity to the strange mass is increased, if only the flavor-breaking difference of strange to non-strange currents is…
We apply, to the new OPAL data on V+A strange spectral functions, a suitable combination of QCD spectral sum rules directly sensitive to the combination of strange quark (m_s) and tachyonic gluon (\lambda^2) masses . Using the mean value of…
The strange quark mass is extracted from a finite energy sum rule (FESR) analysis of the flavor-breaking difference of light-light and light-strange quark vector-plus-axial-vector correlators, using spectral functions determined from…
We present a general analysis of SU(3) breaking effects in the semi-inclusive tau hadronic width. The recent ALEPH measurements of the inclusive Cabibbo--suppressed decay width of the tau and several moments of its invariant mass…
Various complications encountered in the process of attempting to extract the basic Standard Model parameters, m_s and V_us, from hadronic tau decay data are discussed. Preliminary results for V_us, based on sum rules displaying good…
We describe how complications encountered in the extraction of V_us from flavor-breaking hadronic tau decay sum rules, in particular those associated with the slower than previously anticipated convergence of the relevant D=2 OPE series,…
The recent ALEPH measurements of the inclusive Cabibbo--suppressed decay width of the $\tau$ and several moments of its invariant mass distribution are used to determine the value of the strange quark mass. We obtain, in the $\bar{\rm MS}$…
Hadronic tau decays provide several ways to extract the Cabbibo-Kobashi-Maskawa (CKM) matrix element V_{us}. The most precise determination involves using inclusive tau decays and requires as input the total branching ratio into strange…
We report on measurements of branching fractions for several hadronic tau decays to final states with kaons, which can be used to determine the strange quark mass and the element |V_us| of the Cabibbo-Kobayashi-Maskawa quark-mixing matrix.…
The perturbative quark mass corrections to the tau hadronic width are studied to O(alpha_s^3 m_q^2). Including up to dimension four corrections, we get m_s(4 GeV^2)=(143 \pm 42) MeV [m_s(1 GeV^2)=(193 \pm 59) MeV ]. Possible improvements to…
We update the extraction of |V_{us}| from hadronic tau decay data in light of recent BaBar and Belle results on the branching fractions of a number of important strange decay modes. A range of sum rule analyses is performed, particular…