Speaker
Malte Christian Wilfert
(Johannes-Gutenberg-Universitaet Mainz (DE))
Description
The COMPASS experiment at the CERN SPS has taken data for deep inelastic scattering of polarised muons on a polarised NH$_3$ target in 2007 and 2011 and on a polarised LiD target in 2002-2004 and 2006.
We will 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, will be given.
Direct access to the gluon polarisation is possible 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.
Author
Malte Christian Wilfert
(Johannes-Gutenberg-Universitaet Mainz (DE))
