Asymptotic properties of Hulthén model form factors on the light front

We use light-front dynamics to calculate the electromagnetic form factor for the Hulthén model of the deuteron. For a small momentum transfer Q²<5 GeV², the relativistic effects are quite small. For Q²∼11 GeV² there is a ∼13% discrepancy between the relativistic and nonrelativistic approaches. For asymptotically large momentum transfer, however, the light-front form factor ∼lnQ²/Q⁴ differs markedly from the nonrelativistic version ∼1/Q⁴. This behavior is also present for any wave function, such as those obtained from realistic potential models, which can be represented as a sum of Yukawa functions. Furthermore, the asymptotic behavior is in disagreement with the Drell-Yan-West relation. We investigate precisely how to determine the asymptotic behavior, and confront the problem underlying troublesome form factors on the light front.