Measurement of Direct-Photon Cross Section and Double-Helicity Asymmetry at √s =510 GeV in p.sup.→./sup. + p.sup.→./sup. Collisions

0582480 - FZÚ 2024 RIV US eng J - Journal Article
Abdulameer, N.J. - Acharya, U. - Adare, A. - Vrba, Václav … Total 360 authors
Measurement of Direct-Photon Cross Section and Double-Helicity Asymmetry at √s =510 GeV in p^→ + p^→ Collisions.
Physical Review Letters. Roč. 130, č. 25 (2023), č. článku 251901. ISSN 0031-9007. E-ISSN 1079-7114
Institutional support: RVO:68378271
Keywords : calorimeter * electromagnetic * asymmetry * quantum chromodynamics * PHENIX
OECD category: Particles and field physics
Impact factor: 8.6, year: 2022
Method of publishing: Open access

We present measurements of the cross section and double-helicity asymmetry ALL of direct-photon production in p→+p→ collisions at s=510  GeV. The measurements have been performed at midrapidity (|η|<0.25) with the PHENIX detector at the Relativistic Heavy Ion Collider. At relativistic energies, direct photons are dominantly produced from the initial quark-gluon hard scattering and do not interact via the strong force at leading order. Therefore, at s=510  GeV, where leading-order-effects dominate, these measurements provide clean and direct access to the gluon helicity in the polarized proton in the gluon-momentum-fraction range 0.02<x<0.08, with direct sensitivity to the sign of the gluon contribution.
Permanent Link: https://hdl.handle.net/11104/0350966