R.W. Williams

A measurement of the energy dependence of the inclusive yield of high-Pt events triggered by a large solid angle calorimeter

Abstract Large aperture calorimeter measurements of high transverse momentum events from 100, 200 and 340 GeV pp collisions are reported. Yields are higher by one to two orders of magnitude than the yield expected from uncorrelated statistical fluctuations in multiparticle events. The exponential slopes of the yields versus xt exhibited a systematic change with s (x t = 2P t / s ) . The events are shown to be more diffuse than pure jets as produced in e+e− collisions. However, these events are consistent with a QCD-inspired 4-jet model.

Dimuon production by protons in Tungsten

The mass spectrum of dimuons produced by 400 GeV/c protons in Tungsten has been measured for masses greater than 7 GeV. A clear resonant signal of 2700 upsilons has been seen. The dependence of dimuon production on xF and pT has been determined for dimuon masses in the range 7.0 to 8.25 GeV as well as for masses in the upsilon region 8.25 to 9.75 GeV.

A measurement of high-pT correlations in 340 GeV/c pp and 280 GeV/c π−p reactions

We have measured correlations between single high-pT(1.5<pT<3.5 GeV/c) trigger particles on one side of the beam line and groups of particles entering a calorimeter on the opposite side of the beam line. The mean transverse momentum measured in the calorimeter is found to increase with the trigger-particle transverse momentum. The coplanarity of the events increases with trigger-particle transverse momentum. We have compared our data with the predictions of a phenomenological four-jet model. To fit our data we find that we must give large (0.9 GeV/c) mean transverse momenta to the constituents of the initial hadrons.

Single Particle Distributions in Inclusive π−p Reactions at 10.0 and 15.5 GeV/c

Data are presented on single particle distributions from the inclusive reactions π+p⇒π+… and π+p⇒p+… carried out at 10.0 and 15.5 GeV/c. All four pion charge combinations were studied at both energies. Data are available for x≥0 and for transverse momenta up to 0.9 GeV/c. Positive identification of final state particles was accomplished with a Cerenkov counter and time of flight system. Production angles and momentum were measured with spark chambers, proportional chamber and a large aperture magnet.