Paper
Studies of Transverse-Momentum-Dependent distributions with A Fixed-Target ExpeRiment using the LHC beams (AFTER@LHC)
Authors
L. Massacrier, M. Anselmino, R. Arnaldi, S. Brodsky, V. Chambert, W. D. Dunnen, J. Didelez, B. Genolini, E. Ferreiro, F. Fleuret, Y. Gao, C. Hadjidakis, I. Hrivnácová, J. Lansberg, C. Lorc'e, R. Mikkelsen, C. Pisano, A. Rakotozafindrabe, P. Rosier, I. Schienbein, M. Schlegel, E. Scomparin, B. Trzeciak, U. Uggerhøj, R. Ulrich, Z. Yang
Abstract
We report on the studies of Transverse-Momentum-Dependent distributions (TMDs) at a future fixed-target experiment --AFTER@LHC-- using the or Pb ion LHC beams, which would be the most energetic fixed-target experiment ever performed. AFTER@LHC opens new domains of particle and nuclear physics by complementing collider-mode experiments, in particular those of RHIC and the EIC projects. Both with an extracted beam by a bent crystal or with an internal gas target, the luminosity achieved by AFTER@LHC surpasses that of RHIC by up to 3 orders of magnitude. With an unpolarised target, it allows for measurements of TMDs such as the Boer-Mulders quark distributions and the distribution of unpolarised and linearly polarised gluons in unpolarised protons. Using polarised targets, one can access the quark and gluon Sivers TMDs through single transverse-spin asymmetries in Drell-Yan and quarkonium production. In terms of kinematics, the fixed-target mode combined with a detector covering allows one to measure these asymmetries at large in the polarised nucleon.