Charge symmetry breaking in np-->dpi(0).
/ Authors
A. Opper, E. Korkmaz, D. Hutcheon, R. Abegg, C. Davis, R. Finlay, P. W. Green, L. G. Greeniaus, D. Jordan, J. Niskanen
and 5 more authors
/ Abstract
The forward-backward asymmetry in np-->dpi(0), which must be zero in the center-of-mass system if charge symmetry is respected, has been measured to be [17.2+/-8.0(stat)+/-5.5(syst)]x10(-4), at an incident neutron energy of 279.5 MeV. This observable is compared to recent chiral effective field theory calculations, with implications regarding the du quark mass difference.
Journal: Physical review letters