122809176
Measurement of the single-jet invariant cross section at Fermilab
Abstract In an experiment performed at Fermilab we have studied the production of high p t hadron jets from 400 GeV/ c pp interactions. A large solid-angle, towered calorimeter was used to trigger and reconstruct the jet events. We report results for inclusive single-jet production and compare those results with QCD predictions and results obtained at the ISR and the SPS Collider.
198138883
Experimental information on the pion gluon distribution function
An experiment performed at Fermilab used double-arm calorimeter triggers to study di-jet production by 400 GeV protons and 200 GeVπ− mesons incident on liquid hydrogen. The observed ratio of positive to negative leading particles in the jets was compared forpp andπp production using a tree level parton scattering model. The results are moderately sensitive to the form of the pion gluon distribution function and yieldx g(x)⋍(1−x)2.75±0.40±0.75.
120365910
Modular TPCs for relativistic heavy-ion experiments☆
Abstract A description is given of a TPC system that operates in a relativistic heavy-ion beam and yields good track reconstruction efficiency in very-high-multiplicity events. The mechanical construction of the chamber is discussed. A set of custom hybrid circuits are used to build a very compact, cost-effective electronics system mounted directly on the chamber. Results from running in test beams and from preliminary experimental runs are given.
120544624
Triggering on high-transverse-momentum jets
We compare the characteristics of events selected by ''global'' and ''two-high'' triggers in large-transverse-energy hadron-hadron collisions. Using a QCD-based Monte Carlo model of Fox and collaborators, we find that the former is effectively a high-multiplicity trigger, the latter a high-planarity trigger favoring unusually clean jet events. Predictions of the model for both triggers are in good qualitative agreement with recent data.
119722876
Measurement of the dijet cross section in 400-GeV pp collisions
The invariant cross section for production of jet pairs in 400-GeV/c pp interactions has been measured as a function of p{tau} in the p{tau} range 4 to 9 GeV/c. The results are in good agreement with predictions of perturbative QCD models. 20 refs., 3 figs., 1 tab.
125525593
HADRON JETS IN 400-GeV p p COLLISIONS
121339748
MOMENTUM TRANSFER DEPENDENCE IN DIFFRACTION DISSOCIATION.
Abstract The mechanism of kinematic coupling between momentum transfers in producing a low mass two particle system with double-peripheral dynamics is studied theoretically and model calculations. A method of data analysis which eliminates the effects of this kinematic reflection is presented. The data of the reaction pp → pnπ + at 19 GeV/ c have been analyzed using this method. It is seen that the high production slope of the low mass ηπ + system observed in this process is not a cosequences of double-peripheral dynamics plus kinematics but must be explicitly present in the invariant matrix element.
123478569
Coherent production on nuclei does not measure total cross sections for unstable particles
We calculate diffractive production in nucleon-nucleus collisions using a parton model. We fit the result by the standard optical-model formula, and obtain estimates of 12--30 mb for the cross section of the diffractively produced system on a nucleon. The actual value of that cross section in the model is 65 mb. Estimates for the total cross section of an unstable hadron which are based on the A dependence of coherent production should therefore not be trusted.
121052661
Muon pair production in very high energy nucleus-nucleus collisions
Characteristics of muon pair production in very high energy nucleus-nucleus collisions are discussed. Particular attention is given to comparing the rate of muon pairs produced from thermalized quark-gluon matter to that of pairs produced via the usual Drell-Yan mechanism. The thermal rate is at least of the same order of magnitude as the direct Drell-Yan rate and will certainly dominate whenxF for the pair approaches 1. BeyondxF=1 the thermal rate is also substantial. This region is particularly easily accessible in fixed target experiments.
122801502
Quark Dynamics of Polarization in Inclusive Hadron Production
The parton-recombination model plus SU(6) symmetry is used to relate polarizations in inclusive baryon production to those of the underlying constituent subprocesses. A large number of predictions are given, none of which disagrees with experiment. It is suggested that the polarization arises via Thomas precession of the quarks' spins in the recombination process. This description accounts for all of the qualitative features of the baryon and antibaryon polarization data.
121815942
Evidence that hadronic interiors have a denser matter than charge distribution
Abstract An analysis of high-energy elastic and inelastic diffraction scattering provides strong evidence that the charge and matter densities of hadrons are different. When hadrons are treated as composite objects, then a correct Glauber analysis leads to an optical model with important corrections due to the hadronic wave function: One expects inelastic diffraction due to the fluctuations in the matter density of hadrons. Conversely, the experimental existence of dissociation processes gives phenomenological information about the hadronic wave function. We find the distribution of matter in nucleons to be denser than the observed charge distribution. This result has a natural interpretation from a constituent description of hadrons made from spin 1 2 quarks and colored vector gluons, which is a generalization of the Chou-Yang picture of diffraction scattering.