Gluon Polarisation Measurements @ COMPASS
arXiv:1111.0561 · doi:10.1088/0031-8949/2012/T150/014037
Abstract
One of the missing keys in the present understanding of the spin structure of the nucleon is the contribution from the gluons: the so-called gluon polarisation. This quantity can be determined in DIS through the photon-gluon fusion process, in which two analysis methods may be used: (i) identifying open charm events or (ii) selecting events with high p_T hadrons. The data used in the present work were collected in the COMPASS experiment, where a 160 GeV/c naturally polarised muon beam, impinging on a polarised nucleon fixed target is used. Preliminary results for the gluon polarisation from high p_T and open charm analyses are presented. The gluon polarisation result for high p_T hadrons is divided, for the first time, into three statistically independent measurements at LO. The result from open charm analysis is obtained at LO and NLO. In both analyses a new weighted method based on a neural network approach is used.
5 pages, 3 figures, for the Nordic Conference on Nuclear Physics 2011
References in corpus (5)
- The COMPASS Experiment at CERN
- Extraction of Spin-Dependent Parton Densities and Their Uncertainties
- Determination of Polarized PDFs from a QCD Analysis of Inclusive and Semi-inclusive Deep Inelastic Scattering Data
- Gluon polarization in the nucleon from quasi-real photoproduction of high-pT hadron pairs
- ΔG/G results from the COMPASS experiment for Q^2 > 1 GeV^2, using high p_T hadrons