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 |gA ^c| = 0.89 ± 0.44 for the axial vector coupling of the charm quark. © 1983.