Feasibility Studies for Single Transverse-Spin Asymmetry Measurements at a Fixed-Target Experiment Using the LHC Proton and Lead Beams (AFTER@LHC)
Résumé
The measurement of Single Transverse-Spin Asymmetries, $A_N$ , for various quarkonium states and Drell–Yan lepton pairs can shed light on the orbital angular momentum of quarks and gluons, a fundamental ingredient of the proton-spin puzzle. The AFTER@LHC proposal combines a unique kinematic coverage and large luminosities thanks to the Large Hadron Collider beams to deliver precise measurements, complementary to the knowledge provided by collider experiments such as at RHIC. In this paper, we report on sensitivity studies for $J/\psi $ , $\varUpsilon $ and Drell–Yan $A_N$ done using the performance of LHCb-like or ALICE-like detectors, combined with polarised gaseous hydrogen and helium-3 targets. In particular, such analyses will provide us with new insights and knowledge about transverse-momentum-dependent parton distribution functions for quarks and gluons and on twist-3 collinear matrix elements in the proton and the neutron.
Mots clés
parton: distribution function
quark: angular momentum
lead: beam
p: beam
p: spin
CERN LHC Coll
Drell-Yan process
spin: asymmetry
gluon: distribution function
quark: distribution function
transverse momentum dependence
Brookhaven RHIC Coll
sensitivity
performance
kinematics
quarkonium
collinear
hydrogen: target
helium: target
lepton: pair production
proposed experiment