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Delta G from Compass
Measurements of the gluon polarization $\frac{\Delta G}{G}$ via the open charm channel and based on the helicity asymmetry of large transverse-momentum hadrons in the final state are presented. The data have been collected in the years 2002-2004 by the COMPASS experiment at CERN using a 160 GeV/c po...
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Lenguaje: | eng |
Publicado: |
2006
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Materias: | |
Acceso en línea: | https://dx.doi.org/10.1142/9789812706706_0174 http://cds.cern.ch/record/974697 |
Sumario: | Measurements of the gluon polarization $\frac{\Delta G}{G}$ via the open charm channel and based on the helicity asymmetry of large transverse-momentum hadrons in the final state are presented. The data have been collected in the years 2002-2004 by the COMPASS experiment at CERN using a 160 GeV/c polarized muon beam scattered off a polarized $^6$LiD target. The new result for $\frac{\Delta G}{G}$ from the charm channel is $-0.57 \pm 0.41 (stat.)$ at $x_G \simeq 0.15$ and scale $\mu^2 \simeq 13 $ (GeV/c)$^2$. The gluon polarization from high-$p_T$ hadron pairs is $\frac{\Delta G}{G} = 0.016\pm 0.058 (stat.)\pm 0.055 (syst.)$ at $x_G \simeq 0.085^{+0.07}_{-0.035}$ ($Q^2 < 1$ (GeV/c)$^2$ and $\mu^2 \simeq 3$ (GeV/c)$^2$) |
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