Measurement of isolated photon production in hadronic Z decays

The production of high energy isolated photons in hadronic Z decays is measured with the ALEPH detector at LEP using a sample of 180 000 hadronic events. Such photons are mainly radiated by quarks, thus giving direct insights into the early parton showering mechanism. The observed rate is compared with a QCD calculation of final state radiation from quarks

One prong tau decays into charged kaons

Form a sample of about 75000 τ decays measured in the ALEPH detector, 1-prong charged kaon decays are identified by the dE/dx measurement in the central detector. The resulting branching ratios for the inclusive and exclusive modes are: B(τ → ντK− ≥ 0π0 ≥ 0K0) = (1.60±0.07±0.12)%, B(τ → ντK− = (0.64±0.05±0.05)%, B(τ → ντ−π0 = (0.53±0.05±0.07)% and B(τ → ντK−π0π0) = (0.04±0.03±0.02)%. Exclusive modes are corrected for measured KL0 production. The rate for τ → ντK− agrees well with the prediction based on τ - μ universality