High- p T pion quenching versus anti+baryon enhancement in nucleus-nucleus collisions

Abstract

Jet quenching of quarks and gluons in central A + A collisions suppresses the high- p T meson production and exposes novel baryon dynamics that we attribute to (gluonic) baryon junctions. This mechanism predicts baryon enhancement in a finite moderate- p T window that decreases with increasing impact parameter. We also extend recent calculations of the transverse momentum behavior of p/π + and p ¯ / π − to other baryon species and show that a similar pattern is expected for the K −/Λ and K + / Λ ¯ ratios. Within the framework of the model constant p ¯ / p and Λ ¯ / Λ ratios are found in central Au + Au collisions at RHIC energies up to p T ≅ 4 – 5 GeV.