Jul 16 – 22, 2009
Kraków, Poland
Europe/Warsaw timezone

New results on quark helicity distributions and gluon polarization from the COMPASS experiment at CERN

Jul 17, 2009, 11:50 AM
20m
Exhibition room B (Kraków, Poland)

Exhibition room B

Kraków, Poland

The Auditorium Maximum of the Jagiellonian University 33 Krupnicza Street 31-123 Kraków
QCD in hadronic physics VI. QCD in Hadronic Physics

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)

Presentation materials