<human>: Condense the text into a few key points

I recently switched teams within my company after 3 years on the old team.  My new and old team are in a state of quasi-competition, which has resulted in some friction, and as a result I have friction with my old work mates now.

Some examples:  
* One of the reasons I left was that one of my colleagues was creating a toxic environment with her condescending, passive-aggressive remarks, political games, etc.  I found out yesterday that this woman is now going around to people in the company I have not yet met and spinning all kinds of lies about how and why I left.  This is causing damage to my reputation and creating situations that I have to manage.  
* Meanwhile, her supervisor (my old manager) lied to the General Manager about why I left, which I corrected by providing him the notes from the exit interview--he at least believes I am being aboveboard and professional.  I do have other people sticking up for me as well.  
* My old "boss's boss" is aware of the situation and is doing nothing about it.  

I want these people to stop spending time trying to throw me under the bus.  I want my name off their lips.  What's the best way to get this result?

I'm reluctant to go to HR as I haven't observed any of this directly--I just have people coming up to me on a weekly basis "Do you know what so-and-so said about you in the meeting yesterday..."  I also had the manager of another team I just started working with compliment me: "You're not at all what I expected based on what I heard from so-and-so..."

I'm also certain that talking with the old team's management is not going to help, because they're sort of a good-old-boy's club and historically they've encouraged this kind of behavior by letting it slide.  Bad managers don't get fired there.
<bot>: Old coworkers are acting unprofessionally following a switch to a new team, and it's impacting me.  How do I get them to stop?