Direct photon production in d+Au collisions at sqrt(s_NN)=200 GeV at midrapidity
A. Adare
,
E. T. Atomssa
(1)
,
A. Baldisseri
(2)
,
H. Borel
(2)
,
Xavier Camard
(3, 4)
,
J. -L. Charvet
(2)
,
Y. Cobigo
(2)
,
Jean-Pierre Cussonneau
(3, 4)
,
T. Dahms
(1)
,
Hugues Delagrange
(3, 4)
,
O. Drapier
(1)
,
C. Finck
(3)
,
F. Fleuret
(1)
,
S. Gadrat
(5)
,
M. Gonin
(1)
,
J. Gosset
(2)
,
R. Granier de Cassagnac
(1)
,
Ahmed Hadj Henni
(3, 4)
,
B. Lenzi
(2)
,
Gines Martinez Garcia
(3, 4)
,
M. Nguyen
(1)
,
H. Pereira
(2)
,
A. Rakotozafindrabe
(2)
,
G. Roche
(5)
,
P. Rosnet
(5)
,
Yves Schutz
(3, 4)
,
F. Staley
(2)
,
V-N. Tram
(1)
A. Adare
- Fonction : Auteur
Jean-Pierre Cussonneau
- Fonction : Auteur
- PersonId : 15492
- IdHAL : jean-pierre-cussonneau
- ORCID : 0000-0001-5061-4973
- IdRef : 122521285
R. Granier de Cassagnac
- Fonction : Auteur
- PersonId : 739189
- IdHAL : raphgrandecass
- ORCID : 0000-0002-1275-7292
- IdRef : 132136651
Gines Martinez Garcia
- Fonction : Auteur
- PersonId : 169952
- IdHAL : gines-martinez
- ORCID : 0000-0002-8657-6742
- IdRef : 068952961
Résumé
Direct photons have been measured in psNN = 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 due
to a source other than the initial-state nuclear effects.