出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：Measurements of deeply virtual Compton scattering (DVCS) made at HERMES using 27.6 GeV
e beams and various internal polarized or unpolarized gaseous targets are discussed. Results
are reported on the transverse target-spin asymmetry (TTSA) associated with DVCS, extracted
from data accumulated in 2002-2004 with the e+ beam on a transversely polarized hydrogen
target. TTSA amplitudes leading in twist and aS are given as a function of t, xB and Q2 in
the kinematic range jtj < 0:7 GeV2, 0:03 < xB < 0:35 and 1 < Q2 < 10 GeV2. Theoretical
predictions based on a phenomenological model of generalized parton distributions (GPDs) agree
with the experimental results. With additional statistics accumulated in 2005, one may constrain
the u-quark total angular momentum in the nucleon within this model.
