Professor Brian Foster OBE, FRS

Abstract:

Exclusive production of proton-antiproton pairs by two photon scattering at CM energies between 2.0 GeV and 3.1 GeV has been measured with the TASSO detector at the e+e- storage ring PETRA. The angular distribution is flat within the accepted CM angular range |cos Θ*|≤0.7. The integrated cross section (|cos Θ*|≤0.6) drops from about 4 nb at 2 GeV to less than 0.5 nb above 3 GeV. For the two-photon production of the ηc(2984) and its subsequent decay into proton-antiproton the upper limit Γ(ηc→γγ)·B(η c→pp)<0.32 keV (95% CL) is found. © 1983.

Abstract:

We present evidence for the production of Ξ·-, Ξ- in e+e- annihilation into hadrons. Our measurements yields: 0.026 ± 0.008 (stat.) ± 0.009 (syst.) Ξ-,Ξ- per hadronic event at W ∼ 34 GeV. Using our previous measurements of Λ, Λ and p,p production we obtain the relative yields (Ξ-, Ξ-/(Λ, Λ = 0.087 ± 0.03 (stat.) ± 0.03 (syst.) and (Ξ-, Ξ-/(p, p = 0.033 ± 0.011 (stat.) ± 0.011 (syst.). © 1983.

Abstract:

D*± production via e+e-→D*±X has been measured at an average CM energy of 34.4 GeV. The D*± energy spectrum is hard, with a maximum near χ = 0.6. The size of the D* cross section, RD* = σ(e+e- → D*X) σμμ = 2.50 ± 0.64 ± 0.88 (assuming RD*0 = RD*+) indicates that a large fraction of charm quark production yields D* mesons. The D*± angular distribution exhibits a forward-backward asymmetry, A = -0.28 ± 0.13. This is consistent with that expected in the standard theory for weak neutral currents and leads to |gAc| = 0.89 ± 0.44 for the axial vector coupling of the charm quark. © 1983.

Abstract:

The inclusive production of π± and K± mesons and of protons and antiprotons in e+e- annihilation has been measured at c.m. energies of W=14, 22 and 34GeV. Using time of flight measurements and Cerenkov counters the full momentum range has been covered. Differential cross sections and total particle yields are given. At particle momenta of 0.4 GeV/c more than 90% of the charged hadrons are pions. With increasing momentum the fraction of pions among the charged hadrons decreases. At W=34 GeV and a momentum of 5 GeV/c the particle fractions are approximately π±:K±:p, {Mathematical expression}. On average an event at W=34 GeV contains 10.3±0.4π±, 2.0±0.2 K± and 0.8±0.1 p, {Mathematical expression}. In addition, we present results on baryon correlations using a sample of events where two or more protons and/or antiprotons are observed in the final state. © 1983 Springer-Verlag.

Abstract:

We have searched for hadronic decay modes of unstable pointlike charged spin-zero particles such as charged Higgs bosons or technipions, produced in pairs in e+e- annihilation. Together with previous results on leptonic decay modes from other experiments, we conclude that at the 95% confidence level such particles do not exist in the mass range of 5 to 13 GeV. © 1983.