A multi-Regge model with the threshold factor for cluster production

The threshold factor in rapidity space Δ for the production of one additional cluster is shown to have the smaller value 0.1 -- 0.2 than that predicted by Chew and Koplik. The negative correlation among the clusters is brought in through Δ. The weaker correlation, i.e. Δ=0.1, is more provable. The cluster size of 1.3 -- 1.4 negative particles per cluster is predicted as most provable. But the larger value up to 1.7 cannot be excluded. The diffractive cross section is found to be about 9 -- 10 mb and the diffractive multiplicity distribution is shown to be consistent with the Poisson distribution with the mean 1.4 -- 1.7. (auth.)