Possible Defamatory Statements Resulting in Terminiation

My company recently changed CEO's. The new CEO told my supervisor that I slept with the previous CEO to get my position. Also, another member of the executive management team said I "slept my way to the top" to other staff. I am confident that the new CEO is going to demote or lay me off. I did not sleep with the previous CEO (or anyone else in the organization). There are several positions I am qualified for in the new organizational model but unlike everyone else I am not being selected for them. My supervisor said I could apply for a position that paid half my current salary (no one else is having to apply for positions). I have been with the company for 15 years, the most recent years in executive management. The executive manager that spread the rumor is now responsible for the department I use to manage. I feel that I am losing my job and do not have a fair opportunity for another job within the company over defamatory statements. Do I have a potential claim? Thank you