Philip Burrows

Abstract:

We report on total cross section and forward backward charge asymmetry measurements of the reaction e+e- → τ+τ- at centre of mass energies of 35.0 GeV and 42.4 GeV using the TASSO detector. Including previous data an analysis in terms of electroweak parameters of the standard model is presented, and lower limits on mass scale parameters of residual contact interactions are given. A combined analysis of electroweak couplings using all our results on leptonic reactions e+e-→l+l- has been performed. © 1989 Springer-Verlag.

Abstract:

Intermittency effects have been studied directly for the first time in e+e- annihilation, using 37 509 hadronic events at an average CM energy of 〈√s〉=35 GeV. The factorial moments F2, F3 and F4 are given for the rapidity distribution and for the two-dimensional distributions in rapidity and azimuthal angle. The effects of cuts in sphericity and particle momentum are large. Comparison with several fragmentation models are made; some models like the Lund model with O(αs2) matrix element give a qualitative description of the phenomena. The importance of detector effects is demonstrated. The results are discussed in terms of various suggested interpretations of this effect. © 1989.

Abstract:

The production of strange baryons in e⁺e^- annihilation has been studied at centre of mass energies of 34.8 GeV and 42.1 GeV, using the TASSO detector at DESY. Inclusive cross-sections have been obtained for Λ⁰ and Ξ^- production and an upper limit has been placed upon the production rate of Σ^*±(1385). We measure the Λ⁰ multiplicity per event to be {Mathematical expression} and {Mathematical expression} at {Mathematical expression} and 42.1 GeV respectively. The Ξ^- multiplicity per event is found to be {Mathematical expression} at {Mathematical expression}. An investigation has been made of the extent to which Λ⁰ are produced in pairs. The Λ⁰ cross-section has been studied as a function of event sphericity. © 1989 Springer-Verlag.

Abstract:

We present a simple dynamical model of baryon production which predicts the form of baryon fragmentation functions to be softer than that for mesons. These predictions are in good accord with recent measurements of the spectra of baryons produced in e+e- annihilation. The model relates the degree of softening of the baryon fragmentation function to the probability of producing mesons between baryon and anti-baryon. © 1989.