@article{73566ec5c11b46ca895f4a823f14d52e,
title = "Measurement of the spin asymmetry in the photoproduction of pairs of high-pT hadrons at HERMES",
abstract = "We present a measurement of the longitudinal spin asymmetry A|| in photoproduction of pairs of hadrons with high transverse momentum pT. Data were accumulated by the HERMES experiment using a 27.5 GeV polarized positron beam and a polarized hydrogen target internal to the HERA storage ring. For h+h- pairs with pairs with ph1 T>1.5GeV/c and ph2 T>1.0GeV/c the measured asymmetry is A||=-0.28±0.12(stat)±0.02(syst). This negative value is in contrast to the positive asymmetries typically measured in deep inelastic scattering from protons and is interpreted to arise from a positive gluon polarization.",
author = "A. Airapetian and N. Akopov and M. Amarian and Aschenauer, \{E. C.\} and H. Avakian and R. Avakian and A. Avetissian and B. Bains and C. Baumgarten and M. Beckmann and S. Belostotski and Belz, \{J. E.\} and Th Benisch and S. Bernreuther and N. Bianchi and J. Blouw and H. B{\"o}ttcher and A. Borissov and J. Brack and S. Brauksiepe and B. Braun and W. Br{\"u}ckner and A. Br{\"u}ll and Bulten, \{H. J.\} and Capitani, \{G. P.\} and P. Carter and P. Chumney and E. Cisbani and Court, \{G. R.\} and Dalpiaz, \{P. F.\} and \{De Sanctis\}, E. and \{De Schepper\}, D. and E. Devitsin and \{de Witt-Huberts\}, \{N. K.A.\} and \{Di Nezza\}, P. and M. D{\"u}ren and A. Dvoredsky and G. Elbakian and J. Ely and A. Fantoni and M. Ferstl and K. Fiedler and Filippone, \{B. W.\} and H. Fischer and B. Fox and J. Franz and S. Frullani and Funk, \{M. A.\} and Y. G{\"a}rber and W. Korsch",
year = "2000",
doi = "10.1103/PhysRevLett.84.2584",
language = "English",
volume = "84",
pages = "2584--2588",
number = "12",
}