New measurements of at COMPASS

✍ Scribed by S. Koblitz

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 284 KB
• Volume: 174
• Category: Article
• ISSN: 0920-5632
• DOI: 10.1016/j.nuclphysbps.2007.08.082

✦ Synopsis

One of the main goals of the COMPASS experiment at CERN is the determination of the gluon polarisation in the nucleon, ΔG / G. It is determined from spin asymmetries in the scattering of polarised muons at 160 GeV/c on a polarised LiD target. The gluon polarisation is accessed by the selection of photon-gluon fusion events. Such events are tagged either with a charmed meson or a hadron pair with high transverse momenta in the final state. The selection of charmed mesons is based on the reconstruction of decayed D and D 0 mesons in the COMPASS spectrometer. For the high-pT hadron pairs two independent analyses are performed in the kinematic regimes of DIS (Q 2 > 1 (GeV/c) 2 ) and quasi-real photoproduction (Q 2 < 1 (GeV/c) 2 . The results presented in this paper were obtained from the data coming from [2002][2003][2004] for the open charm and the high pT with Q 2 < 1 (GeV/c) 2 channels resp. from 2002-2003 for the high p T with Q 2 > 1 (GeV/c) 2 channel.