prevailed in early universe in first 30 microseconds. The study of color confinement and the transformation of color confining = quark confining vacuum state to the excited state physicists call perturbative vacuum, in which quarks and gluons can roam free, which occurs at Hagedorn temperature; The study the origins of hadron (proton, neutron etc.) matter mass believed to be related to the phenomenon of quark confinement and vacuum structure. Experimental program This experimental program follows on a decade of research at the RHIC collider at BNL and almost two decades of studies using fixed targets at SPS at CERN and AGS at BNL. This experimental program has already confirmed that the extreme conditions of matter necessary to reach QGP phase can be reached. A typical temperature range achieved in the QGP created is more than times greater than in the center of the Sun. This corresponds to an energy density . The corresponding relativistic-matter pressure is More information Rutgers University Nuclear Physics Home Page Publications - High Energy Nuclear Physics (HENP) https://web.archive.org/web/20101212105542/http://www.er.doe.gov/np/ References Nuclear physics Quantum chromodynamics