Susan Cooper

Abstract:

A high statistics experiment was performed on Bhabha scattering at energies between 14 and 34 GeV. Good agreement with QED was observed. The combined data on Bhabha scattering and μ pair production were found to agree with the standard theory of electroweak interaction giving sin2 θ = 0.27-0.07+0.06. Assuming for the Z0 mass a value of 90 GeV the leptonic weak coupling constants were determined to gV2 = -0.04 ± 0.06 and gA2 = 0.35 ± 0.09. A search for scalar leptons sets lower limits on the mass of scalar electrons ofMse > 16.6 GeV and of scalar muons of Msμ > 16.4 GeV. © 1982.

Abstract:

We have observed ρ{variant}0 production in e+e- annihilation to hadrons at high energies. The differential cross section at a centre of mass energy W, of 34 GeV, is presented. In the range 0.2< x < 0.7, we measure 0.33 ± 0.06 (stat.) ± 0.07 (syst.), 0.22 ± 0.06 ± 0.05 and 0.22 ± 0.02 ± 0.05 ρ{variant}0/event at W = 14, 22 and 34 GeV respectively. © 1982.

Abstract:

The scale cross section sdσ dxp for inclusive charged-particle production in e+e- annihilation has been studied for c.m. energies W between 12.0 and 36.7 GeV. Scale breaking is observed. For xp>0.2 the cross section decreases by ≈20% when W increases from 14 to 35 GeV. The production angular distribution was used to separate the longitudinal and transverse cross-section contributions and to determine the ratio of the structure functions mW1 and vW2. © 1982.

Abstract:

The ration R = σ(e+e- → hadrons)σμμ was measured between 12.0 and 36.7 GeV c.m. energy W with a precision of typically ± 5.2%. R is found to be constant with an average R = 4.01 ± 0.03 (stat) ± (syst.) for W ≥ 14 GeV. Quarks are found to be point-like, the mass parameter describing a possible quark form-factor being larger than 186 GeV. Fits including QCD corrections and a weak neutral-current contribution are presented. © 1982.

Abstract:

The inclusive production of π± mesons in e+e- annihilation has been measured at c.m. energies of 14, 22 and 34 GeV for pion momenta between 0.3 ans 10 GeV/c. The fraction of pions among the charged hadrons is above 90% at 0.4 GeV/c and decreases to about 50% at high momenta. The scaled cross sections ( s β) dσ dx at 14, 22 and 34 GeV as well as the 5.2 GeV data from DASP have a rather similar x dependence. After integration over the x range from 0.2 to 0.6 the cross sections indicate a monotonic decrease with increasing centre-of-mass energy. © 1982.