Charge Symmetry Breaking in dd->4He{\pi}0 with WASA-at-COSY
  Charge symmetry breaking (CSB) observables are a suitable experimental tool to examine effects induced by quark masses on the nuclear level. Previous high precision data from TRIUMF and IUCF are currently used to develop a consistent description of CSB within the framework of chiral perturbation theory. In this work the experimental studies on the reaction dd->4He{\pi}0 have been extended towards higher excess energies in order to provide information on the contribution of p-waves in the final state. For this, an exclusive measurement has been carried out at a beam momentum of p=1.2 GeV/c using the WASA-at-COSY facility. The total cross section amounts to sigma(tot) = (118 +- 18(stat) +- 13(sys) +- 8(ext)) pb and first data on the differential cross section are consistent with s-wave pion production. 
WASA-at-COSY Collaboration: P. Adlarson, W. Augustyniak, W. Bardan, M.   Bashkanov, F.S. Bergmann, M. Ber{\l}owski, H. Bhatt...
nucl-ex