Constraining nuclear Parton Density Functions with forward photon production at the LHC

Understand

In this paper we explore the use of results on forward particle production at the LHC to constrain nuclear Parton Density Functions (nPDFs).

• The case study here is based on a possible future measurement of forward photon production with the Forward Calorimeter that is currently under discussion as an upgrade of the ALICE experiment.
• As a starting point, we use the recent nNNPDF 1.0 nuclear PDFs, which have been determined using fixed target neutral-current DIS data, which constrain the gluon density at x > $10^{-2}$.
• The Bayesian reweighting technique is used to include the constraints from the future measurement.