TY - JOUR
T1 - Goodbye to large ΔG? Direct estimate of gluon polarization in the nucleon
AU - Karliner, Marek
N1 - Funding Information:
This talk is based on a joint paper with John Ellis, hep-ph/0501115. The research of M.K. was supported in part by a grant from the Israel Science Foundation administered by the Israel Academy of Sciences and Humanities. We thank Elke Aschenauer, Colin Bernet, Catarina Quintans, Ewa Rondio, Naohito Saito and Robert Thorne for discussions and correspondence.
PY - 2006/11
Y1 - 2006/11
N2 - We make a first crude direct estimate of the net gluon polarization in the proton, ΔG, combining data on the asymmetries in high-pT hadron production from the HERMES, SMC and COMPASS collaborations. Although these data sample a restricted range of x, they provide no hint that ΔG is large. Fixing the normalizations of different theoretical parametrizations using the hadron asymmetry data, we find typical central values of Δ G ∼ 0.5, with uncertainties of similar magnitude. Values of Δ G ≥ 2 are disfavoured by Δ χ2 ∼ 9 to 20, depending on the parametrization used.
AB - We make a first crude direct estimate of the net gluon polarization in the proton, ΔG, combining data on the asymmetries in high-pT hadron production from the HERMES, SMC and COMPASS collaborations. Although these data sample a restricted range of x, they provide no hint that ΔG is large. Fixing the normalizations of different theoretical parametrizations using the hadron asymmetry data, we find typical central values of Δ G ∼ 0.5, with uncertainties of similar magnitude. Values of Δ G ≥ 2 are disfavoured by Δ χ2 ∼ 9 to 20, depending on the parametrization used.
UR - http://www.scopus.com/inward/record.url?scp=33751045866&partnerID=8YFLogxK
U2 - 10.1016/j.nuclphysbps.2006.08.057
DO - 10.1016/j.nuclphysbps.2006.08.057
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AN - SCOPUS:33751045866
SN - 0920-5632
VL - 161
SP - 116
EP - 122
JO - Nuclear Physics B - Proceedings Supplements
JF - Nuclear Physics B - Proceedings Supplements
IS - SPEC. ISS.
ER -