Abstract

Electroproduction of exclusive vector mesons has been studied with the CLAS detector in the kinematic range 1.4?Q2?3.8 GeV2,0.0?t'?3.6 GeV2, and 2.0?W?3.0 GeV. The scaling exponent for the total cross section as 1/(Q2+M2)n was determined to be n=2.49±0.33. The slope of the four-momentum transfer t' distribution is b=0.98±0.17 GeV-2. Under the assumption of s-channel helicity conservation, we determine the ratio of longitudinal to transverse cross sections to be R=0.86±0.24. A two-gluon exchange model is able to reproduce the main features of the data. © 2008 The American Physical Society.