Measurements of the A-dependence of deep-inelastic electron scattering from nuclei

The deep inelastic electron scattering cross sections per nucleon sigma/sub A/ for d, He, Be, C, Al, Ca, Fe, Ag, and Au were measured in kinematic range 0.09 less than or equal to x less than or equal to 0.9 and 2 less than or equal to Q2 less than or equal to 15 (GeV/c)2 using electrons with energies ranging from 8 to 24.5 GeV. The ratio sigma/sub A//sigma/sub d/ is consistent with unity in the range 0.1 < x < 0.3. For 0.3 < x < 0.8, the ratio decreases logarithmically with atomic weight A, or linearly with average nuclear density. No Q2 dependence in the ratio was observed over the kinematic range of the data. This has been interpreted as evidence for a change in the quark momentum distribution in the nucleus due to the presence of 6 quark clusters or a larger nucleon bag size. 13 references