%0 Journal Article %T Low-energy ¦Ð NN system %A Baru V. %J EPJ Web of Conferences %D 2010 %I %R 10.1051/epjconf/20100303003 %X The reaction NN ¡ú NN¦Ð is studied at low energies within chiral perturbation theory (ChPT). Special emphasis is put on p-wave pion production in di erent channels of NN ¡ú NN¦Ð and Charge Symmetry Breaking (CSB) e ects in pn ¡ú d¦Ð0 recently measured at TRIUMF. A very good agreement of the p-wave amplitudes with experimental observables demonstrates the applicability of ChPT to these reactions regardless the large momentum transfer. The results of a complete calculation of CSB e ects at leading order are presented. Based on this calculation we extract the strong contribution to the neutron-proton mass di erence. %U http://dx.doi.org/10.1051/epjconf/20100303003