Possible consequences of the quark model for fragmentation processes

The quark model is used to predict various sum rules for limiting fragmentation. In particular, the ratio of the cross section of p --+ p to that of n --+ n is found to be 9 : 4. An initial combination of the quark model with the generalized optical theorem is found to produce results which violate the quark-model selection rules and differ from experimental values by a factor of 103-106 ? A possible modification is proposed and further tests are suggested.