Direct-Photon Production in p+p Collisions at sqrt(s)=200 GeV at Midrapidity

A. Adare , Laurent Aphecetche (1) , E. T. Atomssa (2) , A. Baldisseri (3) , H. Borel (3) , J. -L. Charvet (3) , T. Dahms (2) , D. d'Enterria (2) , O. Drapier (2) , F. Fleuret (2) , M. Gonin (2) , J. Gosset (3) , R. Granier de Cassagnac (2) , A. Hadj Henni (1) , D. Jouan (4) , B. Lenzi (3) , M. Nguyen (2) , H. Pereira (3) , A. Rakotozafindrabe (3) , G. Roche (5) , P. Rosnet (5) , C. Silvestre (3) , F. Staley (3) , C. Suire (4) , V-N. Tram (2)

1 SUBATECH - Laboratoire SUBATECH Nantes
2 LLR - Laboratoire Leprince-Ringuet
3 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
4 IPNO - Institut de Physique Nucléaire d'Orsay
5 LPC - Laboratoire de Physique Corpusculaire - Clermont-Ferrand

The differential cross section for the production of direct photons in p+p collisions at sqrt(s)=200 GeV at midrapidity was measured in the PHENIX detector at the Relativistic Heavy Ion Collider. Inclusive-direct photons were measured in the transverse-momentum range from 5.5--25 GeV/c, extending the range beyond previous measurements. Event structure was studied with an isolation criterion. Next-to-leading-order perturbative-quantum-chromodynamics calculations give a good description of the spectrum. When the cross section is expressed versus x_T, the PHENIX data are seen to be in agreement with measurements from other experiments at different center-of-mass energies.

Domaines: Physique des Hautes Energies - Expérience [hep-ex]; Physique Nucléaire Expérimentale [nucl-ex]

A. Adare, Laurent Aphecetche, E. T. Atomssa, A. Baldisseri, H. Borel, et al.. Direct-Photon Production in p+p Collisions at sqrt(s)=200 GeV at Midrapidity. Physical Review D, 2012, 86, pp.072008. ⟨10.1103/PhysRevD.86.072008⟩. ⟨in2p3-00703928⟩