Richard Nickerson

Abstract:

The multiplicity of particles associated with electron pairs with mass greater than 11 GeV/c2 is found to increase with the transverse momentum pT of the electron pair. The associated particles are observed to recoil against the electron pair and compensate locally its transverse momentum. The data are compared with lower √s dimuon data using the scaling form: s2pT2(d3 σ/dy dpT2 dm2) = H (xT, y, τ). © 1984.

Abstract:

A sample of 58e⁺e^- events with an invariant mass greater than 11 GeV/c² produced in pp collisions at a centre-of-mass energy of 62.3 GeV is discussed. The cross sections are presented as a function of the mass and transverse momentum. The electron pairs produced with a mean transverse momentum of 2.50 ± 0.25 GeV/c. © 1984.

Abstract:

Most events with high neutral transverse energy, ET0, produced in pp colisions at √s = 62.3 GeV, are jet-like. The evidence for this is presented, based on data collected using an electromagnetic calorimeter covering 90% of 2π in azimuth. The spectrum dN/dET0 has been measured over the ET0 range from 10 to 35 GeV. Properties of the observed jets are discussed. © 1984.

Abstract:

The spectra in total neutral energy, E^TOT0, have been measured in pp, dd and αα collisions at centre-of-mass energy per nucleon pair, sNN, of 31 GeV. The range in ETOT⁰ covered was 1 to 19 GeV in pp, 18 to 24 GeV in dd and 1 to 34 GeV in αα interactions. The ratio of the αα to the pp spectra rises monotonically from 7 at ETOT⁰ = 1.5 GeV to 10⁵ at ETOT ⁰ = 19 GeV. Since ETOT⁰ is the sum over many particles in the detector, it is directly sensitive to multiple nucleon-nucleon collisions in the interacting α particles. The αα spectrum in the range 8 < ETOT⁰ < 17 GeV is consistent with being described by a simple model of 4 simultaneous nucleon-nucleon collisions with a cross section about equal to 10% of the observed αα interaction cross section. The spectrum of ETOT⁰ above 17 GeV is even flatter than this extreme case where four nucleon pairs are interacting. © 1984.