Prompt photon-jet angular correlations at central rapidities in p+A collisions

Scientific paper - Original scientific paper

• Author: Sanjin Benić; MBZ: 310875
• Author: Adrian Dumitru
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

Photon-jet azimuthal correlations in proton-nucleus collisions are a promising tool for gaining information on the gluon distribution of the nucleus in the regime of nonlinear color fields. We compute such correlations from the process g → qq¯ γ in the rapidity regime where both the projectile and target lightcone momentum fractions are small. By integrating over the phase space of the quark which emits the photon, subject to the restriction that the photon picks up most of the transverse momentum (to pass an isolation cut), we effectively obtain a g þ A → qγ process. For nearly back-to-back photon-jet configurations we find that it dominates over the leading-order process q þ A → qγ by two less powers of Q⊥=QS, where Q⊥ and QS denote the net photon-jet pair momentum and the saturation scale of the nucleus, respectively. We determine the transverse-momentum-dependent gluon distributions involved in g þ A → qγ and the scale where they are evaluated. Finally, we provide analytic expressions for hcos nϕi moments, where ϕ is the angle between Q⊥ and the average photon-jet transverse momentum P~ ⊥, and first qualitative estimates of their transverse momentum dependence.

• Keywords (english): Quantum Chromodynamics; quark and gluon jets; photon
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical Review D
• Numbering: vol. 97, no. 1, 014012
• p-ISSN: 2470-0010
• e-ISSN: 2470-0029
• DOI: https://doi.org/10.1103/PhysRevD.97.014012
• URN:NBN: urn:nbn:hr:217:560500
• Publication: 2018
• Project: Number: IP-2013-11-8799; Title (croatian): Tvar i međudjelovanja na ubrzivačima i u svemiru; Acronym: MIAU; Leader: Krešimir Kumerički; Jurisdiction: Croatia; Funding stream: IP
• Document URL: https://journals.aps.org/prd/abstract/10.1103/PhysRevD.97.014012
• Type of resource: Text
• Access conditions: Open access
• Public note: © 2018 American Physical Society. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license https://creativecommons.org/licenses/by/4.0/. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
• Created on: 2020-02-29 21:19:36