No abstract

Ths large qz behavior of the elastic form factor of a hadron or nucleus is related by dimensional counting to the number of its elementary constituents, Using the framework of a scale-invariant quark model, dimensional scaling predictions are derived for the B(q')/A(q') ratio in the Rosenbluth formula, multiple photon exchange corrections, and the mass parameters which control the onset of the asymptotic power law in the meson, nucleon, and deuteron form factors. A simple "democratic chain" model predicts that for large q2, F(q2) cc (1-q2/mi)1-n where rnz is proportional to the number of constituents n. In the case of nuclear targets (or systems with several scales of composite-A ness), we also define the "reduced" form factor fA(q2) = FA(q2)/ fl Fi (q:) in i=l order to remove the minimal falloff of FA due to the nucleon form factors at Dimensional counting predicts (q 2) A-1 fA(S2)-const. A systematic comparison of the data for 71, p, n, and deuteron form factors with the dimensional scaling quark model predictions are given. Predictions are made for the large-q 23 He and o-particle form factors,, We also relate the deuteron form factor to (off-shell) fixed angle n-p scattering, and show that the experimental results for t5FD(t) are consistent with the magnitude of the swave wave function ~~(0) obtained from soft-core potentials. The relation of the dynamics of an underlying six-quark state of the deuteron to the nucleon potential and meson exchange current contributions is discussed, The scaling of q2fD(q2) implies that the nuclear potential (after removing the effects of nucleon structure) displays the scale-invariant behavior of a theory without a fundamental length scale, Predictions are also given for the structure functions, fragmentation, and large angle scattering of a nucleus.

We report preliminary results of elastic e-d scattering at large momentum transfer performed at the Stanford Linear Accelerator Center with use of two high-re solution spectrometers in coincidence. Our results are in sharp disagreement with the mesonexchange calculations, they are in rough agreement with the nonrelativistic potential models, and they are in agreement with the predictions of the quark dimensional-scaling model which pictures the deuteron as a bound state of six quarks at large momentum transfer.

No abstract