Publication Type
Journal
Journal Name
Physical Review C
Publication Date
Page Number
054907
Volume
87
Issue
5
Abstract
Direct photons have been measured in √sNN=200 GeV d+Au collisions at midrapidity. A wide pT range is covered by measurements of nearly real virtual photons (1<pT<6 GeV/c) and real photons (5<pT<16 GeV/c). The invariant yield of the direct photons in d+Au collisions over the scaled p+p cross section is consistent with unity. Theoretical calculations assuming standard cold-nuclear-matter effects describe the data well for the entire pT range. This indicates that the large enhancement of direct photons observed in Au+Au collisions for 1.0<pT<2.5 GeV/c is attributable to a source other than the initial-state nuclear effects.
