Can i sue for slander/defamation of character?

I live in a dormitory on a college campus. Today I had to go to a hearing because my roommate filed reports with the university claiming that I had a gun in the room and that I was a member of the KKK and various Neo-Nazi groups (all are false). Since he filed reports with the University I was wondering if I can sue my roommate for defamation. This has caused me a great deal of mental anguish (pissed me off) and I dont care about salvaging my relationship with him I am moving out next week and changing rooms.