C. DeMarzo

The macro detector at the Gran Sasso Laboratory

Abstract The MACRO detector is presently under construction, its installation at Gran Sasso being planned to start in September 1987. It is a large area detector, the acceptance for isotropic particle fluxes being around 10 000 m 2 sr, designed to search for rare phenomena in the cosmic radiation. It makes use of three detection techniques: liquid scintillator counters, plastic streamer tubes, and track-etch. It will perform a search for GUT monopoles (or any supermassive charged penetrating particle), a survey of cosmic point sources of HE gammas and neutrinos, a systematic study of the penetrating cosmic ray muons, and will be sensitive to neutrino bursts from gravitational stellar collapses in the Galaxy.

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.

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.