Gardener,
That is pretty typical of newly transplanted trees. Often they have substantial root loss when they are sold and it takes a few years for the root system to recover to the point the tree can focus on vegetative growth again. I would say do your best to keep the roots cool and moist and the growth will come in time. I would not suggest fertilizer or any "stimulants" just good ol' H2O until you see the tree begin to push out some new growth. Patience and root TLC will be rewarded with a vigorous grower once it is established. good luck!