can any one suggest any good reading material on operator state mapping in conformal field theory??? I know only elementary field theory... So it might be helpful ifsomeone suggest a book where it is done in little detailed way..
As usual for Conformal field theory, the relevant material is almost assuredly found in the bible on the subject by Di Francesco.
You can also review the following lecture notes online by David Tong: http://www.damtp.cam.ac.uk/user/tong/string/four.pdf (page 99+)
It depends of course on what you want to use it for. If you need to understand the mapping for its applications in something like Ads/CFT, then Tong's lecture notes should suffice, if you are interested in the far more general applications then you'll have to read through the relevant material/sections in Di Francesco. I'd try Tong's notes first, (and there are plenty of other intros/review articles on CFTS) as its a little less formalism rich.