Complete next-to-next-to-leading order calculation of NN → NNπ in chiral effective field theory
1 Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum, Germany
2 Institute for Theoretical and Experimental Physics, 117218, B. Cheremushkinskaya 25, Moscow, Russia
3 Institut für Kernphysik, (Theorie) and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich, Germany and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany
4 Department of Physics and Astronomy, University of South Carolina, Columbia, SC 29208, USA
a e-mail: email@example.com
Published online: 26 November 2014
We present the results of the pion production operator calculated up-to-and-including next-to-next-to-leading order (NNLO) in chiral effective field theory. We include explicit Delta degrees of freedom and demonstrate that they provide essential contribution required to understand neutral pion production data. Analysis of chiral loops at NNLO reveals new mechanisms which are important, but haven’t been considered in phenomenological studies so far.
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