E. W. Anderson

Direct measurement of the lifetime of the neutral pion

Abstract The lifetime of the neutral pion (π0) has been directly measured. The lifetime has been found to be τπ0 = (0.897±0.022±0.017) × 10−16 s. The systematic error results from uncertainties in the momentum spectrum of the π0 used for the measurement. This measurement yields a decay width of the π0 of (7.34±0.18±0.11) eV. An axial anomaly calculation, which neglects the finite mass of the π0, predicts a value of 7.87 eV.

Inclusive production of π0, Ks0, Λ0, and Λ0 in 100, 200 and 360 GeV/c π−p interactions

Inclusive cross sections for π0, Ks0, Λ0 and Λ0 production in 100, 200 and 360 GeV/c π−p interactions are presented and compared with data at other energies. Invariant cross sections for γ, Ks0, Λ0 and Λ0 production are presented in terms of Feynman x, the rapidity y, and transverse momentum squared, pT2. A comparison of the observed γ spectrum is made with the spectra computed assuming that the π0 momentum distribution is identical to that of the observed π+ orπ−.

Two particle correlations in the central region of pp and π−p interactions at 100–300 GeV/c

Abstract Significant positive correlations are seen for all charge combinations of pion pairs with small rapidity separation. Joint rapidity-azimuthal correlations show that this positive correlation occurs when like (unlike) pions are produced with small (large) separation in azimuth.

ρ0production inπ−pinteractions at 100, 200, and 360 GeV/c

Inclusive and semi-inclusive cross sections for rho/sup 0/ production in 100, 200, and 360 GeV/c ..pi../sup -/p interactions are presented. Differential cross sections for rho/sup 0/ production as functions of c.m. rapidity and transverse momentum are compared with the corresponding differential cross sections for pion production. Effects of various methods of estimating background on the values obtained for rho/sup 0/ production cross sections are discussed. About 10% of the final-state charged pions appear to come from rho/sup 0/ decay. Thus, while rho/sup 0/ production and decay is a significant source of final-state pions, other sources must contribute the majority of the produced pions.

A scintillator hodoscope at the Tevatron collider

Abstract A plastic scintillator hodoscope for an experiment at the Fermilab Tevatron proton-antiproton collider is described. The hodoscope is used on-line to form a charged multiplicity trigger and off-line to study charged particle multiplicity distributions. The hodoscope consists of 240 counters covering the pseudorapidity range of ±3.25. It is designed to survive a radiation dose of up to 100 krad over the experiments lifetime.

A quark-gluon plasma search in p̄-p at s = 1.8 TeV

Abstract We present a survey of the recent results of E-735 in its search for QGP signals at the Fermilab Collider. The basic data are the inclusive P t distributions of centrally produced π, K, p and Λ 0 as a function of total charged multiplicity in the collision; the variation of 〈P t 〉 and particle ratios are derived. Preliminary results on π-π correlations and inclusive photon production are also presented.

Semi-inclusive π− cross sections in pp interactions up to 300 GeV/c

Abstract Semi-inclusive π − cross sections in 200 and 300 GeV/ c pp interactions are presented and compared with lower energy data. In the target fragmentation region the data are compared to the hypothesis of semi-inclusive KNO scaling. The energy and charge multiplicity dependences of the semi-inclusive cross sections in the central region are studied and a simple parametrization of the semi-inclusive density function is described.

Three and higher order rapidity distributions in pp collisions at 200 GeV/c

Abstract Three-particle rapidity distributions have been studied for different charged multiplicities in pp interactions at 200 GeV/ c . Appropriately defined semi-inclusive three-particle correlations are found to be sufficiently small, leading us to conclude that the three-particle density can be expressed in terms of one- and two-particle densities. For events with more than four charged particles, a superposition approximation for the three-particle density holds surprisingly well. This approximation enables us to express all higher order rapidity distributions in terms of one- and two-particle distributions alone.

Study of the energy and charged multiplicity dependence of inclusiveπ− production in π−p interactions up to fermilab energies

Abstract Using new data from 100 GeV c π − interactions, we find the energy dependence of the invariant cross-section in the target fragmentation (central) region to be consistent with an A + Bs − 1 2 (C + Ds − 1 4 ) behavior. The leading particle peak near x = + 1 exhibits a width in x which becomes smaller with increasing energy and an integrated cross section which is approximately energy independent.

Recent results from E-735 at the Fermilab Tevatron proton-antiproton collider with √s = 1.8TeV

Abstract E-735 is searching for signs of the quark-gluon-plasma phase transition in minimum bias proton-antiproton events. Results from the 1987 run at the Tevatron Collider at √ s = 1.8TeV are presented. Included are distributions of the average Pt versus multiplicity dependence for charged particles, and preliminary particle identification analysis using time of flight.