Leading-Order Determination of the Gluon Polarization from high-p(T) Hadron Electroproduction - INSPIRE

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Leading-Order Determination of the Gluon Polarization from high-p(T) Hadron Electroproduction

HERMES

Collaboration

•

A. Airapetian
(
- Giessen U. and
- Michigan U.
)

Aug, 2010

45 pages

Published in:

JHEP 08 (2010) 130

e-Print:

1002.3921 [hep-ex]

DOI:

10.1007/JHEP08(2010)130

Report number:

DESY-10-021

Experiments:

DESY-HERA-HERMES

View in:

ADS Abstract Service

reference search86 citations

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Abstract: (arXiv)

Longitudinal double-spin asymmetries of charged hadrons with high transverse momentum

p_T

have been measured in electroproduction using the \hermes\ detector at \hera. Processes involving gluons in the nucleon have been enhanced relative to others by selecting hadrons with

p_T

typically above 1 GeV. In this kinematic domain the gluon polarization has been extracted in leading order making use of the model embedded in the Monte Carlo Generator \Pythia\ 6.2. The gluon polarization obtained from single inclusive hadrons in the

p_T

range 1 GeV

< p_T <

2.5 GeV using a deuterium target is

\frac{\Delta g}{g}(\langle x\rangle, \langle \mu^2\rangle)=0.049\pm 0.034 (stat)\pm 0.010 (sys\textrm{-}exp)^{+0.126}_{-0.099}(sys\textrm{-}models)

at a scale \la\mu^2\ra=1.35~{\rm GeV}^2 and

\langle x\rangle = 0.22

. For different final states and kinematic domains, consistent values of \DGG\ have been found within statistical uncertainties using hydrogen and deuterium targets.

Lepton-Nucleon Scattering
electron p: deep inelastic scattering
electron deuteron: deep inelastic scattering
polarized beam: longitudinal
gluon: polarization
hadron: electroproduction
transverse momentum: high
HERMES
polarization: asymmetry
PYTHIA

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