A MEASUREMENT OF THE KAON CHARGE RADIUS

The negative kaon electromagnetic form factor has been measured in the space-like q2 range 0.015-0.10 (GeV/c)2 by the direct scattering of 250 GeV kaons from electrons at the CERN SPS. It is found that the kaon mean square charge radius = 0.34 +/- 0.05 fm2. From data collected simultaneously for \u3c0e scattering, the difference between the charged pion and kaon mean square radii (which is less sensitive to systematic errors) is found to be - <r2K = 0.1 0 +/- 0.045 fm2

Measurement of B(b)over-bar Correlations At the Cern P(p)over-bar Collider

We report on measurements of correlated bbBAR production in ppBAR collisions at square-root s = 630 GeV, using dimuon data to tag both the b and bBAR quarks. Starting from an inclusive dimuon sample we obtain improved cross-sections for single inclusive beauty production and confirm our earlier results on B0-B0BAR mixing. From a study of bbBAR correlations we derive explicit cross-sections for semi-differential bbBAR production. We compare the measured cross-sections and correlations to O(alpha(s)3) QCD predictions and find good quantitative agreement. From the measured angular distributions we establish a sizeable contribution from higher order QCD processes with a significance of about seven standard deviations. A large nonperturbative contribution to these higher order corrections is excluded

Events With Large Missing Transverse Energy At the Cern Collider .2. Search For the Decays of W+/-into Heavy-leptons and of Z0 Into Noninteracting Particles

We report on further analysis of events with large missing transverse energy from 715 nb-1 of data from the UA1 experiment at the CERN proton-antiproton collider. Measured W and Z0 rates and heavy flavour cross sections are used to predict rates of missing transverse energy event from all known standard model process. Limits are derived on two possible new sources, namely: (1) semi-hadronic decays of a fourth sequential charged heavy lepton coupling to the W boson, (2) Z0 decays into additional pairs of non-interacting particles. After taking into additional pairs of non-interacting particles. After taking into account all known sources of missing transverse energy events, we find a mass limit on a fourth-generation charged lepton of mL&gt;41 GeV/c2 (90% CL) and a limit on the number of additional neutrino species of n≤7 (90% CL). © 1987