Determination of the pi( /-)p ->pi( /-)pi( )n cross section near threshold
JB Lange, F Duncan, A Ambardar, A Feltham, G Hofman, RR Johnson, G Jones, M Pavan, KJ Raywood, D Vetterli, JT Brack, D Ottewell, GR Smith, ME Sevior
PHYSICAL REVIEW LETTERS | AMERICAN PHYSICAL SOC | Published : 1998
The total cross section for the π−p → π−π+n reaction has been measured at incident pion kinetic energies of 200, 190, 184, and 180 MeV. In addition, the π+p → π+π+n reaction was measured at 200 and 184 MeV. A fit of the cross sections by heavy baryon chiral perturbation theory yields values of 8.5 ± 0.6(mπ−3) and 2.5±0.1(mπ−3) for the reaction matrix elements A10 and A32, which correspond to values for the s-wave isospin-0 and isospin-2 π-π scattering lengths of a0 = 0.23 ± 0.08(mπ−1) and a2 = −0.031 ± 0.008(mπ−1), respectively. © 1998 The American Physical Society.