pi0 pi0 Scattering Amplitudes in the pi- p Charge Exchange Process and pi0 pi0 Phase Shift Analysis

TL;DR

This paper analyzes pi0 pi0 scattering amplitudes in the pi- p charge exchange process, extracting phase shifts and resonance parameters, and compares results with standard data and previous analyses.

Contribution

It provides a detailed analysis of pi0 pi0 scattering amplitudes and phase shifts, including resonance parameters, using Chew-Low extrapolation and partial wave analysis, with new agreement findings.

Findings

pi0 pi0 phase shift agrees with pi+ pi- data below 650 MeV

Resonance parameters for sigma meson are precisely determined

pi0 pi0 phase shift deviates from standard data above 650 MeV

Abstract

The amplitude analysis has been performed on the pi0 pi0 final state obtained in the pi- p charge exchange process. The pi0 pi0 scattering amplitudes have been obtained for the S and D waves by the Chew-Low extrapolation and the partial wave analysis. Breit Wigner parameters have been obtained for f0(1370) and f2(1270). I=0 S wave pi0 pi0 scattering phase shift has been obtained below K Kbar threshold. They agree well with the pi+ pi- standard phase shift data below 650GeV and deviate by about 10 degrees from the standard data above 650MeV. They show a different behavior from those of Cason and others. The pi0 pi0 phase shift data have been analyzed by the IA method. Resonance parameters have been obtained to be m_sigma =588 pm 12MeV and Gamma_sigma =281 pm 25MeV with r_c=2.76 pm 0.15GeV^-1. They are excellently in agreement with those obtained in the reanlysis on the pi+ pi- phase shift data.