Abstract
We measured direct photons for in minimum bias and 0%–40% most-central events at midrapidity for collisions at . The contribution from quasireal direct virtual photons has been determined as an excess over the known hadronic contributions in the mass distribution. A clear enhancement of photons over the binary scaled fit is observed for in data. The spectra are consistent with the data covering a similar number of participants. The inverse slopes of the exponential fits to the excess after subtraction of the baseline are and for minimum bias and 0%–40% most-central events, respectively. The rapidity density, , of photons demonstrates the same power law as a function of observed in at the same collision energy.
1 More- Received 13 May 2018
DOI:https://doi.org/10.1103/PhysRevC.98.054902
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Published by the American Physical Society