Experimental evidence against goldstone bosons with only pairwise interactions: More difficulties for broken R-invariance in supersymmetric theories

It is well known that Goldstone bosons cannot couple directly to quarks, except very weakly, without conflict with axion search experiments. We show here that beam-dump experiments also exclude the interesting possibility of Goldstone bosons which are semi-strongly coupled to hadrons through gluons, but only interact in pairs due to a vanishing QCD anomaly. Supersymmetric models with spontaneously broken R-invariance are an example of a class of models which could have exhibited such behavior.