Measurement of Spin-Rotation Parameters in Elastic π~+p Scattering at a Momentum of 1.62 GeV/c and Calibration of a Carbon Polarimeter

摘要

Experimental data on the spin-rotation parameters A and R in elastic π~+p interaction were obtained for the first time at a momentum of p=1.62 GeV/c. These data are necessary for unambiguously reconstructing the amplitude of pion–nucleon scattering and, hence, for deducing a correct spectrum of nonstrange baryon resonances. In order to obtain results for the polarization parameters A and R with the minimum possible systematic error, the carbon polarimeter used was preliminarily calibrated in a dedicated experiment; that is, the analyzing power was measured in proton–carbon scattering for incident-proton energies in the range T_p = 0.7–1.3 GeV. The experimental data reported in the present article were obtained by a collaboration of researchers from the Petersburg Nuclear Physics Institute and Institute of Theoretical and Experimental Physics (ITEP, Moscow) at the ITEP synchrotron.