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

I. G. Alekseev; N. A. Bazhanov; Yu. A. Beloglazov; P. E. Budkovsky; E. I. Bunyatova; E. A. Filimonov; V. P. Kanavets; A. I. Kovalev; L. I. Koroleva; B. V. Morozov; V. M. Nesterov; D. V. Novinsky; V. V. Ryltsov; V. A. Shchedrov; A. D. Sulimov; V. V. Sumachev; D. N. Svirida; V. Yu. Trautman; L. S. Zolin

doi:10.1140/epja/i2008-10709-0

2022 Impact factor 2.7

Hadrons and Nuclei

Eur. Phys. J. A (2009) 39: 163-168
https://doi.org/10.1140/epja/i2008-10709-0

Regular Article - Experimental Physics

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

I. G. Alekseev¹, N. A. Bazhanov², Yu. A. Beloglazov³, P. E. Budkovsky¹, E. I. Bunyatova², E. A. Filimonov³, V. P. Kanavets¹, A. I. Kovalev³, L. I. Koroleva¹, B. V. Morozov¹, V. M. Nesterov¹, D. V. Novinsky³, V. V. Ryltsov¹, V. A. Shchedrov³, A. D. Sulimov¹, V. V. Sumachev³, D. N. Svirida¹, V. Yu. Trautman³ and L. S. Zolin²

¹ Institute for Theoretical and Experimental Physics, 117218, Moscow, Russia
² Joint Institute for Nuclear Research, 141980, Dubna, Moscow area, Russia
³ Petersburg Nuclear Physics Institute, 188300, Gatchina, Leningrad district, Russia

Received: 14 October 2008
Revised: 16 December 2008
Accepted: 22 December 2008
Published online: 26 January 2009

Abstract

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