Can anyone tell me who the top college trumpet professors are
Classical or jazz?
No one is likely to name names in an open forum such as this, it’s just not good manners. However, if we know your interest and ability, we can suggest schools and you can look within that framework.
See, now, I had no idea. Very different in the jazz world; people rattle off who they played with and studied with at a drop of a hat. And no sense of monogamy either… everybody playing with each other, taking lessons from each other’s teachers, etc. 
@Mezzo’sMama, I have seen teachers for other instruments listed in threads here, particularly strings. I think that there are recognized “top teachers” in every instrument, and it doesn’t strike me as bad manners to discuss lists. However, if people feel that it would not be a good idea to discuss trumpet teachers here, there are other forums, including the Trumpet Herald one, where this is discussed openly, and the OP can look there.
I disagree emphatically, @musicalkids. I cannot speak for how things are done in the jazz world, but in the classical music world it is not okay to discuss teachers openly by name. These forums are highly searchable and not nearly as anonymous as some might believe. As a matter of respect for the teachers (and self-preservation), any discussion that involves names of individuals should occur in private.
Gee, what’s the difference between naming a specific school and naming the teacher?
There is a huge difference because specific teachers are human beings with feelings. When we discuss schools we discuss programs, course of study, location-- institutional things.
I can certainly understand that. Agree that “discussing” teachers, which may address both pros and cons and possibly some sort of ranking, would be inappropriate. And I guess asking for the “top” professors implies some level of discussion like that. It’s less of an issue for jazz because, in any given program, there’s often only one professor per instrument.
Still, most professional musicians’ bios and resumes list who they studied with. It’s pretty straightforward to do your own survey of performers you admire to see where they went to school and who they studied with. And doing your own research, based on the criteria that’s important to you, will probably produce more appropriate data than asking random people on an internet forum.