Can i insist a co-worker is terminated for slander?

It turns out this co-worker said i was having an affair with my boss. the statement is completely unfounded and not true. i have a good job and enjoy the people i work with. when i was told someone said this about me i was crushed. as far as i know they have looked into the comment and have found out who said it...can i insist on that person's termination? they said it would be handled appropriately but to me, anything less than termination will not be adequate. this is my life and my career we're talking about here...one comment like this could deminish any credibility i have ever had...