Study of tau decays involving kaons, spectral functions and determination of the strange quark mass
Collaboration
38 pages
Published in:
- Eur.Phys.J.C 11 (1999) 599-618
e-Print:
- hep-ex/9903015 [hep-ex]
Report number:
- CERN-EP-99-026
Experiments:
Citations per year
Abstract:
All ALEPH measurements of branching ratios of tau decays involving kaons are summarized including a combination of results obtained with K^0_S and K^0_L detection. The decay dynamics are studied, leading to the determination of contributions from vector K^*(892) and K^{*}(1410), and axial-vector K_1(1270) and K_1(1400) resonances. Agreement with isospin symmetry is observed among the different final states. Under the hypothesis of the conserved vector current, the spectral function for the K\bar{K}\pi mode is compared with the corresponding cross section for low energy e^+e^- annihilation, yielding an axial-vector fraction of (94^{+6}_{-8})% for this mode. The branching ratio for tau decay into all strange final states is determined to be B(\tau^-\to X^-(S=-1)\nu_\tau)=(28.7\pm1.2)\times 10^{-3}. The measured mass spectra of the strange tau decay modes are exploited to derive the S=-1 spectral function. A combination of strange and nonstrange spectral functions is used to determine the strange quark mass and nonperturbative contributions to the strange hadronic width. A method is developed to avoid the bad convergence of the spin zero hadronic component, with the result m_s(M_\tau^2)=(176^{+46}_{-57}) MeV/c^2. The evolution down to 1 GeV gives m_s(1 {GeV}^2) = (234^{+61}_{-76}) MeV/c^2.Note:
- 34 pages, 12 figures Report-no: CERN-EP/99-026
- review: experimental results
- electron positron: colliding beams
- electron positron: annihilation
- tau: pair production
- tau: semileptonic decay
- tau: branching ratio
- K: production
- decay: amplitude analysis
- universality: (tau muon)
- K*(892)
References(77)
Figures(0)