Inclusive coherent interference phenomena between pions in an S-matrix model

Bubble-chamber data from Fermilab reveal structure at low dipion mass in the two-pion correlation distribution. We explore the possibility that some of this structure may be due to a second-order interference effect generated because of coherent superposition of resonances (for example, due to Bose-Einstein statistics). We consider models for amplitudes in which π and rho mesons are independently produced. A general technique is given for analytically summing the square of these amplitudes to give inclusive distributions. In a specific calculation, the size and range of coherent interference effects are found relative to the amount of inclusive rho production. The effect so generated could account for 10--20 % of the observed low-dipion-mass enhancement