High Energy P+P(P)→P+P(P)+Xj(cc) Process and Two Methods for Calculating Double-Pomeron Exchange Mechanism

Using the X_j(cc) double diffractive production processes in high energy P + P(P) collisions, we have comparatively discussed the D-L phenomenological method of calculating the double-pomeron exchange (DPE) and the method based on the exchange of a pair of nonperturbative color singlet gluons. From the energy dependence of the total cross sections calculated with the two methods we find the two methods fitting well. We conclude that the two methods are consistent.