Speaker
Dr
Krzysztof Kurek
(Soltan Institute for Nuclear Studies)
Description
The new results on quark helicity distributions and on gluon
polarization Delta_G/G from the COMPASS experiment will be presented.
COMPASS is polarized DIS experiment using polarized muons with an energy
of 160 GeV scattered off a polarised deuteron and proton targets.
Quark helicity distributions are obtained from inclusive and
semi-inclusive reactions from 2002-2004 and 2006 deuteron data and from 2007 proton data.
The gluon polarisation Delta_G/G is determined from photon-gluon fusion
(PGF )events. Two methods based on LO QCD approximation are used to
extract PGF events: the selection of open-charm events via observation of
D0 and D* mesons or a pairs of high-pT hadrons. The open-charm result is
obtained from the data collected in 2002-2006 and it is updated with
additional charm contributions. For these
contributions a new method of the signal strength parameterization based
on a neural network classification is used.
The high-pT hadron pair result is obtained from 2002-2004 data using a new
method of accounting for background processes.
Primary author
Dr
Krzysztof Kurek
(Soltan Institute for Nuclear Studies)
