Cross section ratios for deep-inelastic scattering from N-14 and He-3 with
respect to H-2 have been measured by the HERMES experiment at DESY using a
27.5 GeV positron beam. The data cover a range in the Bjorken scaling varia
ble x between 0.013 and 0.65, while the negative squared four-momentum tran
sfer Q(2) Varies from 0.5 to 15 GeV2. The data are compared to measurements
performed by NMC, E665, and SLAG on He-4 and C-12, and rue found to be dif
ferent for x < 0.06 and Q(2) < 1.5 GeV2. The observed difference is attribu
ted to an A-dependence of the ratio R = sigma(L)/sigma(Gamma) of longitudin
al to transverse deep-inelastic scattering cross sections at low x and low
Q(2). (C) 2000 Elsevier Science B.V. All rights reserved.