2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/185905Using a relativistic hadron transport model, we investigate the utility of the elliptic flow excitation function as a probe for the stiffness of nuclear matter and for the onset of a possible quark-gluon-plasma (QGP) phase-transition at AGS energies 1 < E_Beam < 11 AGeV. The excitation function shows a strong dependence on the nuclear equation of state, and exhibits characteristic signatures which could signal the onset of a phase transition to the QGP.11 pages, 4 Postscript figures, uses epsf.sty, submitted to Physical Review LettersNuclear Theorytext