L. I. Koroleva

Measurements of spin rotation parameter A in pion proton elastic scattering at 1.62-GeV/c

Abstract The ITEP-PNPI Collaboration presents the results of the measurements of the spin rotation parameter A in the elastic scattering of positive and negative pions on protons at Pbeam=1.62 GeV/c. The setup included a longitudinally-polarized proton target with superconductive magnet, multiwire spark chambers and a carbon polarimeter with thick filter. Results are compared with the predictions of partial wave analyses. The experiment was performed at the ITEP proton synchrotron, Moscow.

Measurement of the pC analyzing power in the momentum range 1.35–2.02 GeV/c

Abstract The paper presents the experimental results on measurements of carbon analyzing power for polarized protons at momenta 1.36, 1.60, 1.78, 2.02 GeV/ c and the carbon thickness 4.9, 19.4, 36.5 g/cm 2 . The data shows that the analyzing power does not depend on the thickness in the interval 19–36 g/cm 2 . The results of this experiment for carbon thickness 19.4 and 36.5 g/cm 2 together with the Saclay data were used for parametrization over the momentum and the scattering angle. Proton polarization in the quasielastic scattering on carbon at 10.5° was also measured. The experiment was completed at the ITEP accelerator.

Measurement of the spin rotation parameter A+ in the elastic scattering of positive pions on a longitudinally-polarized proton target in the second resonance region

Abstract The ITEP-PNPI collaboration presents the first results of the spin rotation parameter A+ measurements in the second resonance region. The experiment was performed at the ITEP accelerator at a positive pion beam momentum 1.43 GeV/c for scattering angles θcm = 127° and 133°. The setup was based on a polarized proton target and a carbon-plate polarimeter. The obtained data is compared with the predictions of the existing partial-wave analyses.

High-precision measurements of π p elastic differential cross sections in the second resonance region

Cross sections for pi+-p elastic scattering have been measured to high precision, for beam momenta between 800 and 1240 MeV/c, by the EPECUR Collaboration, using the ITEP proton synchrotron. The data precision allows comparisons of the existing partial-wave analyses (PWA) on a level not possible previously. These comparisons imply that updated PWA are required.

Backward asymmetry measurements in the elastic pion-proton scattering at resonance energies

The asymmetry parameter P was measured for the elastic pion-proton scattering in the very backward angular region of

Search for narrow resonances in

\theta_{{\rm CM}}^{}

elastic scattering from the EPECUR experiment

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Measurement of the spin rotation parameter Ain the elastic pion-proton scattering at 1.43 GeV/c

150 - 170° at several pion beam energies in the invariant-mass range containing most of the pion-proton resonances. The general goal of the experimental program was to provide new data for partial wave analyses in order to resolve their uncertainties in the baryon resonance region to allow the unambiguous baryon spectrum reconstructions. Until recently the parameter P was not measured in the examined domain that might be explained by the extremely low cross-section. At the same time the predictions of various partial wave analyses are far from agreement in some kinematic areas and specifically those areas were chosen for the measurements where the disagreement is most pronouncing. The experiment was performed at the ITEP U-10 proton synchrotron, Moscow, by the ITEP-PNPI Collaboration in the latest 5 years.

EPECUR setup for the search for narrow baryon resonances in pion-proton scattering

The analysis of high-precision