6533b858fe1ef96bd12b6460

RESEARCH PRODUCT

Results on longitudinal spin physics at COMPASS

Malte Wilfert

subject

Quantum chromodynamicsPhysicsNuclear and High Energy PhysicsParticle physicsComputer science010308 nuclear & particles physicsPhysicsQC1-999High Energy Physics::PhenomenologyHadronPartonDeep inelastic scatteringEngineering physics01 natural sciencesGluonNuclear physicsCompass0103 physical sciencesCOMPASS experimentHigh Energy Physics::ExperimentSum rule in quantum mechanicsNuclear Experiment010306 general physicsParticle Physics - Experiment

description

Abstract The COMPASS experiment at the CERN SPS has taken data for deep inelastic scattering of polarised muons off a polarised NH3 target in 2007 and 2011 and off a polarised 6LiD target in 2002–2004 and 2006. We present our new results on the longitudinal double spin asymmetry A 1 p and the spin-dependent structure function g 1 p obtained from the 2011 data set. These results are used in a NLO QCD fit to the world data to obtain the polarised parton distributions. Also an update on our results on the Bjorken sum rule, connecting the integral of the non-singlet spin-dependent structure function with the ratio of the weak coupling constants, is given. The gluon polarisation can be accessed directly via the photon gluon fusion process in semi-inclusive deep inelastic scattering. This process is studied using the p T dependence of charged hadron asymmetries. The latest results indicate a positive gluon polarisation in the kinematic region of COMPASS.

https://doi.org/10.1016/j.nuclphysbps.2016.02.010