NEW RESULTS AND PERSPECTIVES ON RAA MEASUREMENTS BELOW 20 GeV CM-ENERGY AT FIXED TARGET MACHINES

Transverse momentum spectra of π at midrapidity are measured at high p T in p+p and p+Pb collisions at 158GeV/nucleon beam energy by the NA49 experiment. This study is complementary to our previous results on the same spectra from Pb+Pb collisions. The nuclear modification factors RA+A/p+p, Rp+A/p+p and RA+A/p+A as a function of p T are extracted and compared to RHIC measurements, thus providing insight into the energy dependence of nuclear modification. The modification factor RA+A/p+A proved to be consistent with our previous results on the central to peripheral modification factor RCP . The limitation of our current p T range is discussed and planned future upgrades are outlined. Some aspects of the FAIR-CBM experiment are also presented as a natural future continuation of the measurements at very high p T .