0000000000541410
AUTHOR
Stephan Narison
The tau-->nu tauetapi process in and beyond QCD
We estimate various sources of the tau-->nu tauetapi process by using QCD-duality sum rule information on the decay constants of standard and exotic mesons. We use the pi--> lnu l decay in order to constrain the effects of new interactions. We conclude from our analysis that in al cases, the tau-->nu tauetapi branching ration is small. We also point out that the present data on the tau-->nupi process already provide an upper limit of 0.1% on the etapi mode while the tau-->nu tauKK¯ data imply an upper limit of 0.5% if the a 0 (980)- meson is a four-quark state.
QCD formulation of the tau decay and determination of Lambda (MS)
Abstract We present a simple formulation of the inclusive and exclusive semi-hadronic decays of the tau lepton using QCD-duality finite energy sum rules (FESRs). We find that the tau decay is a good laboratory for measuring the QCD scaleΛ. Within the present experimental accuracy, we obtain Λ M S ¯ ⋍ 100–200 MeV to four loops. This prediction can be sensibly improved once the experimental situation has been clarified.
QCD analysis of the tau hadronic width
32 páginas, 1 figura, 4 tablas.-- CERN-TH-6070-91 ; NUHEP-TH-91-8 ; PM-91-8.
Semi-inclusive tau decays involving the vector or axial-vector hadronic currents
7 páginas, 1 figura, 4 tablas.