Determination of the s-wave pion–nucleon threshold scattering parameters from the results of experiments on pionic hydrogen

✍ Scribed by G.C. Oades; G. Rasche; W.S. Woolcock; E. Matsinos; A. Gashi

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 166 KB
• Volume: 794
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/j.nuclphysa.2007.07.007

✦ Synopsis

We give the conversion equations which lead from experimental values of the 3p → 1s transition energy in pionic hydrogen and the total width of the 1s level to values of the s-wave threshold scattering parameters for the processes π -p → π -p and π -p → π 0 n respectively. Using a three-channel potential model, we then calculate the electromagnetic corrections to these quantities, which remove the effects of the Coulomb interaction, the external mass differences and the presence of the γ n channel. We give the s-wave scattering parameters obtained from the present experimental data and these electromagnetic corrections. Finally we discuss the implications for isospin invariance.