A study of three-jet events at the CERN {Mathematical expression} collider

The UA2 experiment, running at the CERN SPS {Mathematical expression} Collider, has performed a study of events containing three hard jets in the final state. The angular distributions of the three jets show evidence for gluon bremsstrahlung, in good agreement with a QCD model to leading order in the strong coupling constant αs. The yield of three-jet events relative to that of two-jet events provides a measure of the strong coupling constant: ;3K3/K2=0.23±0.01±0.04, where K2 and K3 represent the contributions arising from higher order corrections in α3 to the two- and three-jet exclusive cross-sections. A detailed discussion of the systematic and theoretical uncertainties is given. © 1986 Springer-Verlag

Experimental study of the emergence of two-jet dominance in p‾\overline{p}p collisions at s\sqrt{s} = 630 GeV

A heuristic model is used to describe data collected by the UA2 experiment at √s = 630 GeV. Distributions of the energy sharing between the leading clusters and the rest of the event are examined. The main features of these distributions can be described by a two-component model with soft, collective interactions dominating at low transverse energy and hard, constituent interactions dominating at high transverse energy. This model provides a simple picture of the emergence of two-jet dominance at SPS pp Collider energies. © 1985

Measurement of W± and Z0 properties at the CERN {Mathematical expression}p collider

A study of W± and Z0 properties has been performed using the UA2 detector at the {Mathematical expression} collider. The data correspond to a total integrated luminosity of 142 nb-1 at {Mathematical expression}=546 GeV, and of 310 nb-1 at {Mathematical expression}=630 GeV. The experimental results are compared with the predictions of the Standard Model of the unified electroweak theory. © 1986 Springer-Verlag

Direct photon production at the CERN p‾\overline{p}p collider

Using the UA2 apparatus, the inclusive cross section has been measured for production of high-pT direct photons in p̄p collisions at s=546 GeV and s=630 GeV. The results are in good agreement with QCD predictions. © 1986