RPM indicator goes beyond 6000, car does not move

I drive a Nissan Sentra 1.8S (Auto Trans) 2005 model. It is only 3 months old and ran 7,500 miles so far. I was driving at 60 MPH speed and suddenly the car start de-accelareting. As I pressed the accelarator, the RPM indicator goes beyond 6,000 with a loud noise but the car does not move. So I stopped, tried again and same thing happens. I stopped again and then start. No problem. Car runs smoothly. Can you please suggest me any problem that the car may have.
Thanks and I would appreciate your help.

Sounds like it may have slipped into nuetral. It drives fine now?

:iagree: