Search

Total cross sections for π − , K − and p on protons and deutrons have been measured in the momentum range 15 to 60 GeV/c. Total cross sections for particle interactions with neutrons have been determined with an energy dependent Glauber correction. Using the positive particle data obtained earlier with the same experimental apparatus, the differences of total cross sections for particles and antiparticles as well as for particles belonging to the same isospin multiplet have been calculated. The differences of total cross sections for particles and antiparticles decrease with momentum following a power law. The differences between the pure isospin state cross sections are either close to zero or continue to decrease. The measured total cross sections and their differences are in agreement with relations predicted by quark and Regge-pole models.

The reaction π−p→Ks0Ks0n was studied at the incident momentum 40 GeV/c making use of the 6 m magnetic spark spectrometer MSS ITEP. Partial wave analysis was carried out using ∼ 6700 events of this reaction with t′

The paper presents the results on differential cross sections for elastic scattering of 7+-, K+-mesons and protons on protons in the 4-momentum transfer squared range 0·08 ≦¦t¦≦ ≦1·0 (GeV/c)2 and incident particle momentum of 29 and 43 GeV/c for pions and kaons and 29, 43, 50 and 65 GeV/c for protons. The measurements were taken with the spectrometer Sigma, installed in the positive beam of the IHEP accelerator.

The absorption cross sections of antideuterons with the momentum P = 13.3 GeV/c by Li, C, Al, Cu and Pb nuclei have been measured. Antiproton stripping of antideuterons has been registered and its cross section for C, Al and Cu has been defined. The binding energy of antideuteron is found to be ed = 2.4 ± 0.6 MeV by measuring the angular distribution of antiprotons from stripping.

Total cross-section data are presented for negative pions, kaons, and antiprotons on protons and deuterons in the momentum range 20 GeV/c to 65 GeV/c in 5 GeV/c steps.

The paper describes differential Cerenkov counters detecting Cerenkov light at the angles of 23 and 12 mrad. The counter lengths are 5 m (θ = 23 mrad) and 10 m (θ = 12 mrad). The spectrum band of the counters is 2500–6000 A. The counter characteristics have been investigated in 35 to 45 GeV/c beams of the 70 GeV accelerator. The velocity resolutions measured are equal to 2×10−6 for a 10 m counter and 6×10−6 for a 5 m counter. The 10 m counter can separate pions and kaons up to 200 GeV/c and kaons and protons (antiprotons) up to 350 GeV/c.

This paper describes a 5 m gas Cerenkov threshold counter with a velocity resolution δ = 6.5 × 10 −6 . Resolution of δ = = 3.6 × 10 −6 has been achieved as the result of summarizing the signals from two counters. High velocity resolution has been obtained due to the effective registration of Cerenkov light in the short-wave region (counter spectral range: 1800–6000 A). The threshold counter characteristics have been investigated in 5 to 60 GeV/c beams of the 70 GeV accelerator. The particle registration efficiency on the plateau is more than 99.99994%. The probability of the particle registration below the threshold is less than 3 × 10 −4 .

d p and p d total cross-sections have been measured at 13.3 and 6.65 GeV/c respectively to check CPT-invariance. The standard transmission technique was used. The difference of d p and p d total cross-sections appeared to be equal 0.2 ± 2.6 mb. In addition d d and p p total cross-sections have been obtained. The experimental data allowed us to derive the total cross-section of antineutrons on protons, neutrons and deutrons.

The yields of pions, kaons, antiprotons and antideuterons, produced by the 70 GeV protons on Al and Be nuclei at the momenta 10 and 13.3 GeV/ c have been measured. Gas Cerenkov counters and time-of-flight spectrometers were used for particle identification.