Speaker
Description
Forward pp and p+A measurements at the LHC probe the same QCD dipole scattering amplitudes as ep and e+A measurements at the EIC, and a comprehensive search for non-linear QCD evolution effects (“saturation”) requires extensive measurements at both facilities. The ALICE Forward Calorimeter upgrade (FoCal) provides a key element in this program. FoCal is a highly-granular forward calorimeter, which will be installed as an ALICE upgrade subsystem during LHC Long Shutdown 3 and take data during LHC Run 4. FoCal covers the pseudorapidity interval $3.2 < \eta < 5.8$, measuring direct photons, neutral mesons, vector mesons, jets, and their correlations, in hadronic and UPC pp and p+Pb collisions. These measurements will explore QCD evolution down to unprecedentedly low values of Bjorken-$x\approx10^{-6}$ at moderate $Q^2$, where non-linear QCD evolution effects are expected to be sizable. In this presentation I will discuss the FoCal detector and its projected physics performance in multiple measurement channels. The EIC, FoCal, and LHCb detector together provide “logarithmically large” coverage in x, which is essential to explore QCD evolution, and I will also discuss the question of combining such heterogeneous dataset to provide global constraints.
