Go to the non-leaved portion of the tree, and try to bend a small branch. If it breaks, it's dead. Redbud are notorius in my experience for having trouble when transplanted. Was the original tree in a pot, or balled and burlaped, or bareroot. They often dieback, but the "good part" is that they'll resprout from roots. Was this a "general/generic" redbud or a special cultivar (there are now cultivars that show red or yellow coloring on the new growth or varigated leaves or have differences in their flowers). If it was a special cultivar, it was likely grafted and you now have a "generic" redbud. If you were only planting a regular/generic redbud do the following: Find out if there is any growth from the original trunk. If there is no growth in the original trunk, use and handsaw and cut off at the ground. If the growth from the original trunk is alive but weak (and this is not a special cultivar [see paragraph above]), I'd do the same thing. Then decide the following: Do you want a single trunk'd tree or a multi-trunked tree? If single remove all but the strongest stem. If multi-trunked leave the three strongest and remove the rest. It should do fine. I did know one tree that died to the ground twice before hitting its stride, but it will eventually reward you with a great tree.

I agree with Ken, and he may or may not have implied this - don't do anything until spring. Let it overwinter as-is before cutting anything. There's a thread out there about a blackgum (Nyssa sylvatica) that faced a similar fate and has been retrained into a nice, single trunk tree, but I can't locate it at hte moment. A couple posters' adventures in the same species, in fact, but could act as a guide for your Redbud.

Some years ago I had a Chinese pistache tree that had been growing beautifully and one spring after leafing out all the leaves drooped. Upon close inspection I could see tiny holes around the trunk below where the branches came out. It was infested with some sort of beetle. I cut the tree below the holes and treated the tree around the ground with a systemic product to target the pests. There was one branch unaffected as it was below the infestation. The tree rapidly grew more branches. Don't give up...look for suspicious damage.

take a hand trowel.. and dig 2 or 3 six inch holes ... AND FIND OUT AT ROOT DEPTH .... how wet the soil is ... why guess ... find out ... try to let the soil NEAR dry in between deep waterings ... minor leaf damage is never a concern.. on a deciduous tree ... cut off the small dead branch ... the white rings look like spider sacs ... or some type of cocoon ...... ignore until you see 2000 of them.. lol ... frankly ... it looks great ... you dont even want to know significant transplant stress .. which you dont have ... relax.. and try not to kill it with too much love ... ken