Search

The paper presents results on measuring the polarization in the reaction π − p→ π 0 n at 40 GeV/ c in the 4-momentum transfer range 0 t |⩽2 (GeV/ c ) 2 . The results based on the statistics of about 2.2 million recorded events made it possible to observe a noticeable value and complex structure in the polarization behaviour up to | t |⩽2 (GeV/ c ) 2 .

Differential cross sections for the elastic scattering of negative pions on protons, as well as total cross sections have been measured for the incident momentum range from 33 up to 60 GeV/c. The values for four-momentum transfer were within the limits of −(10−3−8·10−2) (GeV/c)2. The energy dependence of the ratio ϱ(0) of the real part of the forward elastic scattering amplitude to the imaginary part has been determined from the experimental data. The magnitude ϱ(0) smoothly increases from (−10.9 ± 1.2)% at momenta 33.52 GeV/c up to (−1.8 ± 1.8)% at 59.4 GeV/c. The results obtained are compared with the predictions of theoretical models.

The π − p differential elastic scattering cross sections have been measured for eight momenta in the 33–55 GeV/ c range. The energy dependence of the slope and of the total elastic scattering cross sections has been determined experimentally. The results are compared with the known data. The experimental data are compared both with the Regge pole model and with the quasi-potential one.

The differential cross sections for elastic π − p, K − p , p p and π + p, pp scattering at 39 and 44.5 GeV/c, respectively, have been measured in the interval of momentum transfer squared 0.15 ≤ ovbt| ≤ 2 (GeV/c)2.

The helicity amplitudes for isospin-0 exchange are determined at 40 GeV/ c . For isospin-1 exchange only partial information is obtained. The model-independent analysis is extended to the four-momentum transfer interval from t = 0 to t = −0.6 (GeV/ c ) 2 . One of the two solutions presented has a behaviour similar to the previous results at lower energy.