High-energy neutrino physics at the LHC

High-energy collisions at the LHC and its High-Luminosity upgrade (HL-LHC) produce a large number of particles along the beam collision axis, outside of the acceptance of existing experiments. The FASER experiment has in 2023, for the first time, detected neutrinos produced in LHC collisions, and is now starting to elucidate their properties. FASER data has the potential to improve our understanding of the strong interactions as well as of proton and nuclear structure, providing access to both the very low-x and the very high-x regions of the colliding protons. The former regime is sensitive to novel QCD production mechanisms, such as BFKL effects and non-linear dynamics, as well as the gluon parton distribution function (PDF) down to very small Bjorken-x values, well beyond the coverage of other experiments and providing key inputs for astroparticle physics. In addition, FASER acts as a neutrino-induced deep-inelastic scattering (DIS) experiment with TeV-scale neutrino beams. The resulting measurements of neutrino DIS structure functions represent a valuable handle on the partonic structure of nucleons and nuclei, particularly their quark flavour separation, that is fully complementary to the charged-lepton DIS measurements expected at the upcoming Electron-Ion Collider (EIC). In this project, the student will carry out updated simulations of neutrino scattering and detection at FASER, assess the precision with which neutrino cross-sections will be measured, develop novel monte carlo event generation tools for high-energy neutrino scattering, and quantify their impact on proton and nuclear structure by means of machine learning tools within the NNPDF framework and state-of-the-art calculations in perturbative Quantum Chromodynamics. Specifically, we aim to determine whether FASER data can detect intrinsic charm in the proton and whether FASER can find evidence for BFKL small-x QCD dynamics, complementing studies provided by other experiments such as the LHC detectors.