We have measured the moment ALUsinφ corresponding to the polarized electron beam-spin asymmetry in semi-inclusive deep inelastic scattering. ALUsinφ is a twist-3 quantity providing information about quark-gluon correlations. Data were taken with the CLAS Spectrometer at Jefferson Lab using a 5.498 GeV longitudinally polarized electron beam and an unpolarized liquid hydrogen target. All three pion channels (π+, π0 and π-) were measured simultaneously over a large range of kinematics within the virtuality range Q2≈1.0-4.5GeV2. The observable was measured with better than 1% statistical precision over a large range of z, PT, xB, and Q2, which permits comparison with several reaction models. The discussed measurements provide an upgrade in statistics over previous measurements, and serve as the first evidence for the negative sign of the π- sinφ moment.
|Original language||English (US)|
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|State||Published - Apr 11 2014|
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)