First saturation correction in high energy proton-nucleus collisions. Part III. Ensemble averaging

Journal Article · 26 January 2022 · Journal of High Energy Physics (Online)

DOI: https://doi.org/10.1007/jhep01(2022)160 · OSTI ID:1845870

Li, Ming  ^[1]; Skokov, Vladimir V. ^[2]

---

1. North Carolina State Univ., Raleigh, NC (United States); North Carolina State University
2. North Carolina State Univ., Raleigh, NC (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)

In high energy proton-nucleus collisions, the gluon saturation effects from the nucleus are fully incorporated into the light-like Wilson lines. The gluon saturation effects from the proton, which are anticipated to be important either in the extreme high energy limit or towards the dense-dense (nucleus-nucleus) collision regimes, have been studied perturbatively within the Color Glass Condensate effective theory in previous papers of this series. A configuration-by-configuration expression for the single inclusive semi-hard gluon production including the first saturation correction was obtained. In this paper, we perform ensemble averaging in the McLerran-Venugopalan model and the Dipole Approximation. We find that, in the saturation correction, the effects of the initial state interactions are negligible while the final state interactions play most important role and give a positive-valued contribution to the semi-hard gluon spectrum. Furthermore, we show that the single gluon spectrum scales approximately 1/$$k$$$^{4}_{⊥}$$ at small k_⊥, suggesting that a resummation of higher order saturation corrections is required to regulate the infrared region of the gluon spectrum.

• Research Organization: North Carolina State Univ., Raleigh, NC (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Grant/Contract Number: SC0020081
• OSTI ID: 1845870
• Journal Information: Journal of High Energy Physics (Online), Journal Name: Journal of High Energy Physics (Online) Journal Issue: 1 Vol. 2022; ISSN 1029-8479
• Publisher: Springer NatureCopyright Statement
• Country of Publication: United States
• Language: English