出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We present preliminary results on the production of intermediate mass dimuons in 158 AGeV
In-In collisions at the CERN SPS. NA38 and NA50 observed a strong excess in this region in
S-U and Pb-Pb interactions with respect to the dimuon production rate expected from p-A data.
Thanks to the use of a pixel vertex tracker, NA60 can separate the prompt dimuons from the pairs
resulting from open charm decays and show that the excess dimuons are of prompt origin.
