First results on angular distributions of thermal dileptons in nuclear collisions

NA60 Collaboration: R. Arnaldi , K. Banicz , K. Borer , J. Castor , B. Chaurand , W. Chen , C. Cicalo , A. Colla

show 44 more authors

P. Cortese S. Damjanovic A. David A. de Falco A. Devaux L. Ducroux H. En'yo J. Fargeix A. Ferretti M. Floris A. Foerster P. Force N. Guettet A. Guichard H. Gulkanian J. M. Heuser M. Keil L. Kluberg Z. Li C. Lourenco J. Lozano F. Manso P. Martins A. Masoni A. Neves H. Ohnishi C. Oppedisano P. Parracho P. Pillot T. Poghosyan G. Puddu E. Radermacher P. Ramalhete P. Rosinsky E. Scomparin J. Seixas S. Serci R. Shahoyan P. Sonderegger H. J. Specht R. Tieulent G. Usai R. Veenhof H. K. Woehri

Authors on Pith no claims yet

classification ⚛️ nucl-ex

keywords distributionsthermalangularcollisionsexcessfirstfoundradiation

0 comments

read the original abstract

The NA60 experiment at the CERN SPS has studied dimuon production in 158A GeV In-In collisions. The strong excess of pairs above the known sources found in the complete mass region 0.2<M<2.6 GeV has previously been interpreted as thermal radiation. We now present first results on the associated angular distributions. Using the Collins-Soper reference frame, the structure function parameters \lambda, \mu and \nu are measured to be zero, and the projected distributions in polar and azimuth angles are found to be uniform. The absence of any polarization is consistent with the interpretation of the excess dimuons as thermal radiation from a randomized system.

This paper has not been read by Pith yet.

First results on angular distributions of thermal dileptons in nuclear collisions

discussion (0)