Squeezed Correlations Among Particle-Antiparticle Pairs

The hadronic correlation among particle-antiparticle pairs was highlighted in the late 1990's, culminating with the demonstration that it should exist if the masses of the hadrons were modified in the hot and dense medium formed in high energy heavy ion collisions. They were called Back-to-Back Correlations (BBC) of particle-antiparticle pairs, also known as squeezed correlations. However, even though they are well-established theoretically, such hadronic correlations have not yet been experimentally discovered. Expecting to compel the experimentalists to search for this effect, we suggest here a clear way to look for the BBC signal, by constructing the squeezed correlation function of phi phi and K+K- pairs at RHIC energies, plotted in terms of the average momentum of the pair, K-12=1/2(k(1) + k(2)), inspired by procedures adopted in Hanbury-Brown & Twiss (HBT) correlations.