Study of isolated prompt photon production in $p$-Pb collisions for the ALICE kinematics

Abstract

Prompt photon production is known as a powerful tool for testing perturbative QCD predictions and also the validity of parton densities in the nucleon and nuclei especially of the gluon. In this work, we have performed a detailed study on this subject focusing on the isolated prompt photon production in $p$-Pb collisions at forward rapidity at the LHC. The impact of input nuclear modifications obtained from different global analyses by various groups on several quantities has been investigated to estimate the order of magnitude of the difference between their predictions. We have also studied in detail the theoretical uncertainties in the results due to various sources. We found that there is a remarkable difference between the predictions from the nCTEQ15 and other groups in all ranges of photon transverse momentum $p_{\text{T}}^{\gamma }$. Their differences become more explicit in the calculation of the nuclear modification ratio and also the yield asymmetry between the forward and backward rapidities rather than single differential cross sections. We emphasize that future measurements with ALICE will be very useful not only for decreasing the uncertainty of the gluon nuclear modification, but also to accurately determine its central values, especially in the shadowing region.

12 pages, 10 figures

References in corpus (20)

• Glauber Modeling in High Energy Nuclear Collisions
• Parton distributions in the LHC era: MMHT 2014 PDFs
• EPS09 - a New Generation of NLO and LO Nuclear Parton Distribution Functions
• Determination of nuclear parton distribution functions and their uncertainties at next-to-leading order
• A new critical study of photon production in hadronic collisions
• Quantitative constraints on the gluon distribution function in the proton from collider isolated-photon data
• Electromagnetic radiation from nuclear collisions at RHIC energies
• Differential cross section measurements for the production of a W boson in association with jets in proton-proton collisions at sqrt(s) = 7 TeV
• Measurement of differential production cross-sections for a $Z$ boson in association with $b$-jets in 7 TeV proton-proton collisions with the ATLAS detector
• Measurement of the production cross section of an isolated photon associated with jets in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector
• Probing gluon saturation with next-to-leading order photon production at central rapidities in proton-nucleus collisions
• A systematic study of direct photon production in heavy ion collisions
• Sensitivity of isolated photon production at TeV hadron colliders to the gluon distribution in the proton
• Photon - Jet Correlations and Constraints on Fragmentation Functions
• Quark-Gluon Matter
• Probing the small-$x$ nuclear gluon distributions with isolated photons at forward rapidities in p+Pb collisions at the LHC
• Measuring gluon shadowing with prompt photons at RHIC and LHC
• A measurement of the ratio of the production cross sections for W and Z bosons in association with jets with the ATLAS detector
• Reconsideration of the inclusive prompt photon production at LHC with kt-factorization
• Nuclear shadowing and prompt photons at relativistic hadron colliders

Cited by in corpus (6)

• Study of spin-dependent structure functions of ${}^3\mathrm{He}$ and ${}^3\mathrm{H}$ at NNLO approximation and corresponding nuclear corrections
• Prompt photon production in high-energy $pA$ collisions at forward rapidity
• Predictions for the isolated prompt photon production at the LHC at $\sqrt{s}=$13 TeV
• Improved determination of $\bar{d}(x)-\bar{u}(x)$ flavor asymmetry in the proton by BONuS experiment at JLAB and using an approach by Brodsky, Hoyer, Peterson, and Sakai
• Parton distribution functions with QED corrections in the valon model
• Single photon production in ppBar collision in the collinear and kt-factorisation framework and investigation of their differences