Next Article in Journal
Natural Products and the Hallmarks of Chronic Diseases NutRedOx COST Action 16112—Personalized Nutrition in Ageing Society: Redox Control of Major Age-Related Diseases
Previous Article in Journal
Comparison of Redox Properties of Flavonoid Aglycones and Corresponding Glycosides and Their Mixtures in the Cellular Model
Article Menu
Issue 1 (HQ 2018) cover image

Export Article

Open AccessProceedings

Photons as Probes of Gluon Saturation in Dilute + Dense Collisions

Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan
Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg, Germany
Physics Department, Brookhaven National Laboratory, Bldg. 510A, Upton, NY 11973, USA
Author to whom correspondence should be addressed.
Presented at Hot Quarks 2018—Workshop for Young Scientists on the Physics of Ultrarelativistic Nucleus-Nucleus Collisions, Texel, The Netherlands, 7–14 September 2018.
Proceedings 2019, 10(1), 33;
Published: 18 April 2019
PDF [267 KB, uploaded 18 April 2019]


We use the Color Glass Condensate (CGC) effective field theory (EFT) to calculate inclusive photon production to leading order q g q γ , (LO), and next-to leading order g g q q ¯ γ (NLO) at LHC energies. These processes dominate the photon production at small-x , where x 0 . 01 in the target and projectile protons. We show that the NLO contribution dominates at values of x typical at the LHC, since its cross-section is sensitive to the gluon distributions in both protons. We perform a comparison of our results to the available inclusive photon data, from ATLAS and CMS at center-of-mass energies of 2 . 76 and 7 TeV . This data lies in the range k > 20 GeV . We show that for this range, the k -factorized cross-section converges to the full CGC EFT result, and can be used for the comparison. We find that it gives good agreement with experimental results. Our results are to be considered as a first step towards constraining unintegrated gluon distributions, which will be continued for larger systems, where coherent scatterings are enhanced.
Keywords: prompt; inclusive; photon; saturation; color glass condensate prompt; inclusive; photon; saturation; color glass condensate
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Benić, S.; Fukushima, K.; Garcia-Montero, O.; Venugopalan, R. Photons as Probes of Gluon Saturation in Dilute + Dense Collisions. Proceedings 2019, 10, 33.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Metrics

Article Access Statistics



[Return to top]
Proceedings EISSN 2504-3900 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top