  A novel type of correlation involving particle-antiparticle pairs was found
out in the 1990's. Currently known as Squeezed or Back-to-Back Correlations
(BBC), they should be present if the hadronic masses are modified in the hot
and dense medium formed in high energy heavy ion collisions. Although
well-established theoretically, such hadronic correlations have not yet been
observed experimentally. In this phenomenological study we suggest a promising
way to search for the BBC signal, by looking into the squeezed correlation
function of phi phi and K^+ K^- pairs at RHIC energies, as function of the pair
average momentum, K_{12}=(k_1+k_2)/2. The effects of in-medium mass-shift on
the identical particle correlations (Hanbury-Brown & Twiss effect) are also
discussed.
