Analysis of the Low-Energy π^±p Elastic-Scattering Data

E. Matsinos, G. Rasche

Centre for Applied Mathematics and Physics, Zurich University of Applied Sciences, Winterthur, Switzerland.
Institut fur Theoretische Physik der Universitat, Zurich, Switzerland.

DOI: 10.4236/jmp.2012.310174                

Abstract

We report the results of a phase-shift analysis (PSA) of the low-energy π^±p elastic-scattering data. Following the method which we had set forth in our previous PSA [1], we first investigate the self-consistency of the low-energy π^±p elastic-scattering databases, via two separate analyses of (first) the π⁺p and (subsequently) the π^-p elastic-scattering data. There are two main differences to our previous PSA: 1) we now perform only one test for the acceptance of each data set (based on its contribution to the overall ²) and 2) we adopt a more stringent acceptance criterion in the statistical tests. We show that it is possible to obtain self-consistent databases after removing a very small amount of the data (4.57% of the initial database). We subsequently fit the ETH model [38] to the truncatedπ^±p elastic-scattering databases. The model-parameter values show reasonable stability when subjected to different criteria for the rejection of single data points and entire data sets. Our result for the pseudovector πNN coupling constant is 0.0726±0.0014. We extract the scattering lengths and volumes, as well as the s- and p-wave hadronic phase shifts up to T = 100 MeV. Large differences in the s-wave part of the interaction can be seen when comparing our hadronic phase shifts with the current SAID solution (WI08); there is general agreement in the p waves, save for the ^~1/2_1- hadronic phase shift.

Keywords

πN Elastic Scattering; πN Hadronic Phase Shifts;πN Coupling Constants; πN Threshold Constants

Conflicts of Interest

The authors declare no conflicts of interest.

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