Franco Bonaudi

Observation of single isolated electrons of high transverse momentum in events with missing transverse energy at the CERN pp collider

Abstract We report the results of a search for single isolated electrons of high transverse momentum at the CERN p p collider. Above 15 GeV/c, four events are found having large missing transverse energy along a direction opposite in azimuth to that of the high-pT electron. Both the configuration of the events and their number are consistent with the expectations from the process p + p → W ± + anything , with W→e+ν, where W± is the charged Intermediate Vector Boso postulated by the unified electroweak theory.

Evidence for Z0→e+e− at the CERN p collider

Abstract From a search for electron pairs produced in p p collisions at s = 550 GeV we report the observation of eight events which we interpret as resulting from the process p +p→Z 0 + anything, followed by the decay Z0→e++e− or Z0→e++e−+γ, where Z0 is the neutral Intermediate Vector Boson postulated by the unified electroweak theory. We use four of these events to measure the Z0 mass M Z = 91.9 ± 1.3 ± 1.4 (systematic) GeV /c 2 .

Observation of very large transverse momentum jets at the CERN pp collider

The distribution of total tranverse energy ΣET over the pseudorapidity interval −1 < η < 1 and an azimuthal range Δφ=300° has been measured in the UA2 experiment at the CERN pp collider (s = 540 GeV) using a highly segmented total absorption caloriter. In the events with very large ΣET (ΣET⪆60 GeV) most of the transverse energy is found to be contained in small angular regions as expected for high transverse momentum hadron jets. We discuss the properties of a sample of two-jet events with invariant two-jet masses up to 140 GeVc2 and we measure the cross section for inclusive jet production in the range of jet transverse momenta between 15 and 60 GeVc.

The central calorimeter of the UA2 experiment at the CERN pp collider

Abstract The highly segmented electromagnetic and hadronic calorimeter of the UA2 experiment has been successfully operated at the CERN p p Collider for more than 3 years. The mechanical design and construction technique of the calorimeter as well as its performance and stability in test beams and at the p p Collider are described in detail.

Inclusive Charged Particle Production at the CERN anti-p p Collider

Transverse momentum distributions of pions, kaons and protons have been measured around 90° in the UA2 detector at the SPS p p collider, at a CM energy of 540 GeV. All the cross sections have increased by more than a factor of 2 over those measured at ISR energies and exhibit a flatter behaviour with respect to transverse momentum.

Measurement of production and properties of jets at the CERN\(\bar pp\) collider

AbstractThe production and properties of high transverse momentum hadron jets have been measured in the UA2 experiment at the CERN

Inclusive particle production in the transverse momentum range between 0.25 and 40 GeV/c at the CERN\(Sp\bar pS\) collider

\bar pp

A new search for relativistic particles with fractional electric charge at the CERN pp collider

Collider