D. Rahm

Absorption cross section of π±, K±, p and p on nuclei between 60 and 280 GeV/c

Abstract Absorption cross sections of π±, K±, p and p have been measured on targets of Li, C, Al, Cu, Sn and Pb at 60, 200, and 280 GeV/c.

A large liquid-argon shower detector for an ISR experiment

A large liquid-argon shower detector system has been constructed for the detection of photons and electrons at the CERN ISR. The calorimeter system is built in a modular way such that eight modules would cover = 2 π azimuthally with a total solid angle of Ω = 8 sr. Each module consists of 1.5 mm thick lead plates, spaced 2 mm apart. Longitudinal grouping and transversal division into strip-like sections of the charge-collecting electrodes provide the required spatial resolution and hadron discrimination. Measurements on energy and space resolution and electron/hadron discrimination are described. The signal-processing system, designed to minimize electronics noise, can handle event rates up to 0.5 MHz and provides energy information for trigger purposes. The performance of this calorimeter system during two years of ISR operation is reported.

Performance of a liquid argon electromagnetic calorimeter with an “accordion” geometry

Abstract The first prototype of a lead—liquid-argon e.m. calorimeter with accordion-shaped absorber and electrode plates has been built and tested with electron and muon beams at the CERN SPS. This novel geometry combines good granularity with high readout speed and minimal dead space. For a response peaking time of 140 ns, an energy resolution of 10%/ E[ GeV ] and a space resolution of 4.4 mm/ E[ GeV ] with a 2.7 cm cell size have been achieved for electrons. The position accuracy for muons is better than 2 mm.

Identified pion interferometry in heavy-ion collisions at CERN

Abstract π + π + correlations from S + Pb collisions at 200 GeV/ c per nucleon, measured by the focusing spectrometer of the NA44 experiment at CERN, are presented. The large data set, particularly at small values of Q inv , allows determination of the detailed shape of the correlation function. We construct the background by event mixing, and correct for resolution, Coulomb interaction, and distortion of single-particle spectra which produce effects large compared to the statistical errors at small Q inv . An exponential, rather than gaussian, source distribution is slightly favoured, but both are statistically acceptable.

Study of photons produced simultaneously with the J/ψ particles at the CERN intersecting storage rings

Abstract As a part of the study of the inclusive production of electron pairs in pp collisions at the CERN Intersecting Storage Rings (ISR), a search has been performed for additional photons accompanying J/ψ particles. The results suggest that (43±21)% of the J/ψs are produced via the photonic decay of one of the χ(3.5) states.

High-p T direct photon production inpp collisions

AbstractDirect photon and neutral-pion production have been measured inpp collisions at the CERN ISR for 30<

A comparison of direct photon, π0 in pp and pp interactions at the CERN ISR

\sqrt s

Three Pion Correlations in Sulphur Lead Collisions at the CERN SPS

<63 GeV and transverse momenta up to 12 GeV/c. The direct photon signal relative to neutral-pion production increases withpT and shows little