2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/81856One of the most dramatic results from the first RHIC run are the STAR results for pi+- pi+- interferometry. They showed that the ratio of the so-called R_{out} and R_{sid} radii seem to decrease below unity for increasing transverse momentum of the pair (K_T). This was subsequently confirmed by PHENIX, which also extended the K_T range of the measurements. We consider here the effects of opacity of the nuclei on this ratio, and find that such a small value is consistent with surface emission from an opaque source.24 pages, 8 Postscript figures; factor corrected in Eq.(15)Nuclear TheoryHigh Energy Physics - PhenomenologyNuclear Experimenttext