L. Rosenson

Measurement of p̄p→π0π0, π0η0 in the T and U-meson region

Abstract We present measurements from a counter-optical spark chamber experiment of the differential cross sections for pp → π 0 π 0 , π 0 η 0 at 25 momenta in the range 1.1 − 2.0 GeV/ c (c.m. energy 2.12 to 2.43 GeV). Approximately 750 000 pictures were taken in the experiment.

Observation of structure in p̄p → π0π0

Abstract We present a partial wave amplitude analysis of the differential cross sections for pp → π 0 π 0 at 25 energies from 2.12 to 2.43 GeV. The results suggest the presence of a J PC I G = 2 ++ 0 + resonance at 2.15 GeV. An isospin decomposition of pp → π + π - is also presented.

Differential cross sections for backward π− p → nπ0 from 2.6 to 8 GeV/c

Abstract We report differential cross sections for π − p → n π 0 in the backward hemisphere at incident momenta of 2.6, 3.5, 4.3, 6.0, and 8.0 GeV/c. We observe less pronounced structure than some previous measurements with a shallow dip displaced from that seen in π + p elastic scattering.

A 4π scintillation counter-optical spark chamber system for neutral particles

Abstract We describe a scintillation counter - optical spark chamber system developed for the detection of high energy gamma rays and neutrons. We describe the system components and their use in two completed experiments.

THE USE OF AN INTERNAL LIQUID HYDROGEN TARGET WITH A METHYL IODIDE BUBBLE CHAMBER

Design and use of a 15 in. dia. by 14 in. deep methya iodide chamber with a small internal target of liquid H/sub 2/ are described. Such a system is useful for the study of reactions on free protons with pi /sup 0/ among the products. (J.R.D.)

Alternate polarity multiple spark gap for high efficiency shower detectors

Abstract The developments in the hv pulsing system which have been made in order to reduce the rise time and the delay of the hv pulse at the plates of a large spark chamber system are reported. Higher efficiency has been achieved feeding each chamber through an alternate polarity multiple spark gap.

A PORTABLE 5 cm FREON BUBBLE CHAMBER FOR THE INVESTIGATION OF PARTICLE BEAM PROFILES

A freon bubble chamber weighing 100 lb and with overall dimensions of 18 x 18 x 7 is described. It was used successfully to investigate the cross sectional shape of a particle beam and to facilitate adjustment of the beam magnets to produce the desired shape. It could also be used to investigate the convergence or divergence of a beam. (A.G.W.)

Measurement of neutral to charged pion ratio in pp annihilations in the 2200 MeV mass region

The relative probability distribution of π±and π0 mesons in pp annihilation was measured in 10 MeV bins from 2.15 to 2.23 GeV. No significant variation in probabilities was found, and mean values are consistent with those reported at 2.28 GeV. Observed multiplicity distributions are consistent with two-body cascading on the statistical model under equal weighting of G = ±1 states.