Isospin breaking exposed in f0(980)−a0(980) mixing

We suggest that mixing between the f0(980) and a0(980), due to their dynamical interaction with the nearby KK̄ thresholds, can give rise to a significantly enhanced production rate of a0(980) relative to a2(1320) in pp→ps(ηπo)pf as xF→0. The peaking of the cross section as φ→0 should also occur. We show that such effects are seen in data and deduce that the f0(980)−a0(980) mixing intensity is 8±3 %.