Sources of charge symmetry breaking:

1
Scientific Motivation
Sources of charge symmetry breaking primary (1)
Coulomb and/or magnetic forces (2) down-up
quark mass difference secondary (appearing in
meson-exchange models) (1) meson mixing (r w,
or p h, h) (2) neutron-proton mass difference
Chiral perturbation theory provides organizing
framework.
Experimental input for primary sources
(1) Neutron-proton mass difference
mn-mp 1.29 MeV Dm DmduDmg
Electromagnetic Dmg -1 MeV thus quark term
Dmdu few MeV
(2) Fore-aft asymmetry in np6dp0
CSB mixes outgoing P-wave with S-wave near
threshold
Run completed on spectrometer at TRIUMF. Data
taking done. Analysis nearly complete. Expected
asymmetry error 0.0010 (in sf-sb/sfsb) The
oretical predictions Dm Dmdu-Dmg /2 6
0.0060 ph mixing 6 -0.0037
(3) Isospin-forbidden dd64Hep0
Total cross section is square of a CSB amplitude.
Experiment to be run at IUCF Cooler Construction
and commissioning underway Expected sensitivity,
sTOT lt 2 pb Theoretical predictions Dm
Dmdu-Dmg /2 but with little meson
mixing Theoretical effort organized by G. Miller
and U. von Kolck.