S. Katcoff

A Single arm spectrometer detector system for high-energy heavy ion experiments

The recent availability of 14.6 GeV/c per nucleon 16O and 28Si ions from the Brookhaven National Laboratory Tandem-AGS accelerator facility has prompted the design, construction and operation of a large-solid-angle (25 msr) magnetic spectrometer with particle identification from ∼0.5 to ∼4.7 GeV/c. A small-solid-angle Cherenkov counter complex views the target through the magnet and extends the particle identification up to ∼15 GeV/c. This experiment (E-802) employs event characterization detectors, a charged-particle multiplicity array, a highly segmented lead-glass detector, and a zero degree calorimeter. The facility measures momentum spectra of identified heavy-ion-produced hadrons with high resolution (Δp/p≤0.005) as a function of collision centrality given by triggers from the event characterization detectors. Construction and performance details of the spectrometer components and auxiliary detectors are described.

Measurement of energy emission from O+A and p+A collisions at 14.5 GeV/c per nucleon with a lead-glass array

Abstract The first data from a 16O beam of total energy 232 GeV at the BNL Tandem-AGS are reported. A lead-glass array covering the laboratory pseudo-rapidity interval 1.25

Results from the BNL E802 spectrometer for 14.5 GeV/c per nucleon silicon beams

We present selected results of measurements of inclusive ..pi.., K, proton, and deuteron spectra from 14.5 A GeV/c Si collisions with various targets. Results of neutral energy and charged particle dN/d/eta/ measurements are also discussed. Large K to ..pi.. ratios are observed in Si + Au collisions. Results are compared to the Lund-Fritiof model. 11 refs., 11 figs.

Recent results from E802 and E859

Abstract Recent single-particle inclusive measurements and two-particle correlation data from E802 and its succesor, E859, are presented. The K + / π + ratio observed for collisions of 14.6 A·GeV 28 Si ions on various targets is presented as a function of both forward and transverse energy. Source sizes are determined via interferometry using π + , π − , K + and proton pairs.

Measurement of energy and charged particle emission in the central rapidity region from O+A and p+A collisions at 14.5 GeV/c per nucleon and preliminary results from Si+A collisions

The first data from a16O beam of total energy 232 GeV at the BNL Tandem-AGS are discussed. Preliminary results from a28Si beam of total energy 406 GeV are also shown. The full complement of E802, including a magnetic spectrometer, was used for the28Si measurement. A different experimental arrangement was used for16O. Comparison measurements with proton beams are presented for both configurations.

Centrality dependence of K+ and π+ multiplicities from Si + A collisions at 14.6 A GeV/c☆

Abstract K + and π + multiplicities have been measured in magnetic spectrometer for Si++ Al, Si+ Cu and Si + Au collisions at 14.6 A GeV/ c incident momentum. The multiplicities were obtained for five different windows of forward kinetic energy as detected in a zero degree calorimeter. The K + / π + multiplicity ratio ranges from ≈9% in peripheral interactions to 19% in central Si+Au. The largest K + / π + ratios are observed for those events for each target that leave the least energy in the zero degree calorimeter and the ratio increases with target mass. The observations suggest that multiple interactions are important in the particle production mechanism.

A calorimeter for relativistic heavy-ion experiments

Abstract An iron-scintillator sampling calorimeter is described for measurement of the energy of projectile-like fragments and forward reaction products from interactions of 13.6 GeV/nucleon heavy ions with complex nuclei. Studies of the response of this device to charge- and mass-identified ions from 1 H to 28 Si indicate good linearity over the range 14–381 GeV with a resolution, σ E of 0.73 GeV 1 2 . Some factors that influence the resolution of heavy-ion calorimeters are discussed.

Intermittency in central collisions of 16O+A at 14.6A GeV/c☆

Abstract Fluctuations in pseudorapidity distributions of charged particles from central collisions of 16 O+Al and 16 O+Cu at 14.6 A GeV/ c are analyzed using scaled factorial moments. A power-law growth of moments with decreasing bin size is observed down to δη ∼ 0.1. About half the measured signal remains after making corrections based on Monte Carlo calculations with Fritiof and GEANT which include γ-conversions, Dalitz decays and detector effects.

Bose-Einstein correlations in 14.6 A · GeV/c 28Si + A collisions

Abstract The E802 spectrometer at the Brookhaven AGS has been used to obtain two-particle inclusive pion distributions from E / A = 14.6 GeV 28 Si + 197 Au arid 27 A1 interactions. Data are presented for pions near center-of-mass rapidity, in the nucleon-nucleon frame, from central events. We present preliminary results for source distribution parameters obtained by fitting the two-particle correlation function. The potential for studying kaon correlations in the E802 apparatus is also discussed.

Proton production from Si+Au collisions at 14.5 A-GeV

Abstract Recent results are presented from the study of central Si+Au → p+X, Si+Au → π±+X, and Si+Cu → p+X at 14.5 A.GeV. The distribution of protons in rapidity indicates that many target protons are found above 0.5 units. The variation of the slope parameter in rapidity is consistent with a thermal source of protons at the geometric center-of-mass rapidity.