Professor Brian Foster OBE, FRS

Abstract:

We have determined the D0 lifetime from reconstructed vertices of D0 mesons produced in e+e- annihilations at an average center of mass energy of 42.2 GeV. From fifteen events the D0 lifetime was determined to be (4.3-1.4+2.0±0.8)×10-13s. © 1986 Springer-Verlag.

Abstract:

Bose-Einstein correlations between pairs of charged particles produced in e+e- annihilation into hadronic final states have been studied as a function of Q2, the relative momentum squared of the two particles in their centre of mass, and as functions of various pairs of kinematic variables. The observed Bose-Einstein enhancement reveals correlation between the position and time of particle emission, and the space-time structure of the source is shown to differ from that of a pion fireball. While most features of the data are well accounted for in terms of the space-time structure of a simple string model, the correlations are better described by the simple function 1+αe-βQ2. The implications of this result are discussed. The principal features of three particle correlations are explained in terms of the structure of the source inferred from the observed two particle correlations. © 1986 Springer-Verlag.

Abstract:

Vector meson production is studied in the reaction γγ→K⁺K^-π⁺π^-. A clear Φ(1020) signal is seen in the K⁺K^- mass distribution and a K^*0 (890) signal is visible in the K^±π^∓ one. Both do not seem to be strongly correlated with quasi two body final states. Cross sections for the processes γγ→K⁺K^-π⁺π^-, γγ→Φπ⁺π^-, γγ→K⁺⁰K^±π^∓ and upper limits for the production of Φp, ΦΦ and K^*0 {Mathematical expression} are given as function of the invariant γγ mass. © 1986 Springer-Verlag.

Abstract:

The cross section for the process e+e-→π0+ anything has been measured at an average center of mass energy of 34.6 GeV for π0 energies between 0.7 and 17 GeV. The angular distribution for π0 energies larger than 2 GeV is of the form dσ/dΩ∼1+Acos2θ, with A=1.2±0.5. The ratio of π0 to π± production in the measured energy range is 2σ(π0)/(σ(π+)+σ(π-))=1.13±0.18 The form of the differential cross sections agrees within the errors. The mean π0 multiplicity is 5.8±0.9. © 1986 Springer-Verlag.

Abstract:

We have studied the correlations between charged particles produced in e+e- annihilations into hadrons at c.m. energies between 29 and 37 GeV. We have analysed the correlations between the charged multiplicities of the jets and the two particle rapidity and charge correlations. No evidence for correlations between the multiplicities of the two jets is found. Two particle short range rapidity and charge correlations are observed, indicating that particles cluster in rapidity and that their charges compensate locally. An extensive study of these correlation effects by QCD Monte Carlo calculations was performed. Evidence for charge correlations due to Bose-Einstein statistics is also observed. © 1985 Springer-Verlag.