Evidence for a Large Breaking of Charge Independence in theNNInteraction

In an energy-dependent phase-shift analysis of all np scattering data below Tlab=30 MeV, we find a large breaking of charge independence in the πNN coupling constants g₀² and gc². For 495 degrees of freedom we obtain χₘᵢₙ²=533.8 and Δg²≡gc²-g₀²=1.28±0.15. A combined analysis, including also all pp scattering data below Tlab=30 MeV, results in χₘᵢₙ²=847.2 for 840 degrees of freedom. We then obtain Δg²=1.62±0.27. The effect of such large values for Δg² is most strikingly seen in the ³P waves. The np³P phase shifts at Tlab=25 MeV are much larger than those of our phase-shift analyses.