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New Measurements of $\Delta G/G$ at COMPASS
The COMPASS experiment at the CERN SPS is investigating the spin structure of the nucleon via scattering of polarised muons off polarised nucleons. Using a longitudinally polarised $^{6}$LiD target inclusive asymmetries and asymmetries for the photon gluon fusion process were determined. From the in...
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Lenguaje: | eng |
Publicado: |
2006
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Materias: | |
Acceso en línea: | https://dx.doi.org/10.1063/1.2402721 http://cds.cern.ch/record/1026770 |
Sumario: | The COMPASS experiment at the CERN SPS is investigating the spin structure of the nucleon via scattering of polarised muons off polarised nucleons. Using a longitudinally polarised $^{6}$LiD target inclusive asymmetries and asymmetries for the photon gluon fusion process were determined. From the inclusive asymmetries the spin structure function, $g^{d}_{1}$ , is extracted in a wide kinematical range of $x$ and $Q^{2}$. The results are used in a subsequent NLO pQCD analysis of all existing $g_{1}$ data to determine the contribution of the quarks to the nucleon spin and to estimate the gluon contribution. The photon gluon fusion process allows a direct measurement of the gluon contribution. Here, two different channels, open charm production and the production of high $p_{T}$ hadron pairs, are investigated. Preliminary results from both LO analyses using all COMPASS data from 2002 to 2004 are presented. They point to a small gluon contribution in agreement with the results from the QCD analysis. |
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