SPECULATIONS ON THE BREAKDOWN OF SCALING AT 10 - 15 cM J

Hints from existing data suggest that deviations from scaling behavior should appear at momenta ]q21 ;G (20 GeV2). We interpret the deviations as due to structure of the hadronic constituents at 10 -IL5 cm . and make experimental predictions. The observed scaling behavior for deep inelastic electron scattering suggests that hadrons may be composed of point-like spin l/2 constituents (partons) from which the virtual photon scatters incoherently, 1 In configuration space, one says that the virtual photon is probing the leading light cone singularity of the current commutator. 2 The picture seems almost too good to be true, in that the onset of this presumably asymptotic phenomenon occurs for surprisingly small values of the mass (Q 2 5 -q 2 ) and laboratory energy (v) of the virtual photon. Nonetheless, it is tempting to proclaim that we have glimpsed the elementary, structureless building blocks from which hadrons are constructed: that nothing remains between us and the light cone. Here we wish to propose a less exuberant perspective on the meaning of scaling: that it represents the shedding of just another layer of the onion, 3 and that hints of the structures to be discovered in the next _----T-7 layer are already in evidence. Our view is old-fashioned,4 in that it -*Work supported by the U.S. Atomic Energy Commission. (Submitted to Physical Review Letters)