Measurement of the polarization parameter P in π−p elastic scattering in the energy range 450–600 MeV

Phase-shift analysis of ?+ p-scattering in the energy region from 194 to 600 MeV

“…The results of the LNPI PSA are compared in Figs. 1 and 2 with the results of the latest phase-shift analyzes [6,21,24] that do not utilize the data on P(O) obtained in LNPI [2,3]. The inverse solutions of the LNPI PSA are assigned asterisks.…”

“…In those cases when the difference in energy was only 10-20 MeV linear interpolation of o-(O) and P(O) was performed with respect to the energies and angles (within 2~ The quantities Reg(0) [8] and ato t [9,10] were interpolated accounting for the adjacent experimental points. Upon finding each solution we excluded those experimental points in a(O) and P(O) for which Z2~ [3][4]. Those experimental data in overlapping angular intervals for which statistical errors were significantly higher than in later and more accurate experiments were also excluded.…”

“…Within the framework of this program at the LNPI the measurements of the differential cross sections a+(O) [-1] and of the polarization parameters P_+(O) [2,3] in ~-+p scattering have been carried out. Before the investigations were initiated, and during accumulation of experimental data at the LNPI, phase-shift analyses (PSA) of ~N scattering were performed [-4, 5].…”

Measurement of the polarization parameterP in? + p elastic scattering in the region of low-lying pion-nucleon resonances

“…Measurement of the polarization parameter P in ~z+p scattering is a part of this program. Earlier experimental data [3][4][5][6] were quite scarce and did not allow to obtain a complete picture of the behaviour of the parameter P vs. angle and energy. Moreover, some of these measurements had such large errors that it was very difficult to determine the shape of dependences P(O*) even qualitatively.…”

“…The experiment was performed on a pion channel [7] of the LNPI synchrocyclotron using a polarized proton target [-8] and wire spark chambers with magnetostrictive read-out [9]. The experimental layout is shown in Fig.…”