Chiral effective field theory predicts a specific charge symmetry violating amplitude for pion production. This term is shown to provide the dominant contribution to the forward-backward asymmetry in the angular distribution for the reaction pn → dπ 0 , for reasonable values of the mass difference between down and up quarks, δm N . Using a value δm N ≈ 3 MeV leads to a prediction of a 10 standard deviation effect for a TRIUMF experiment.
Using multiple scattering theory the scattering lengths of η mesons on helium nuclei are calculated and checked against final state η interactions from the pd → η 3 He and dd → η 4 He reactions. The existence of an η 4 He quasibound state is indicated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.