Role of the Delta(1232) in pion-deuteron scattering at threshold within chiral effective field theory
arXiv:0706.4023 · doi:10.1016/j.physletb.2007.10.063
Abstract
We investigate the role of the delta isobar in the reaction at threshold in chiral effective field theory. We discuss the corresponding power counting and argue that this calculation completes the evaluation of diagrams up to the order (m_pi/M_N)^(3/2), with m_pi (M_N) for the pion (nucleon) mass. The net effect of all delta contributions at this order to the pion-deuteron scattering length is (2.4 +/- 0.4)x 10^(-3) m_pi^{-1}.
11 pages