Many new states in the charmonium mass region were recently discovered by the BaBar, Belle and CDF Collaborations. We use the QCD Sum Rule approach to study the possible structure of some of these states.
We study the kaon-to-vaccum weak matrix element using the method of the QCD duality finite energy sum rules. It is found that the matrix element in question can be expressed as a sum of two terms: one behaving like ms−md and the other like [Formula: see text]. Detailed numerical estimates are also given.
Sum Rule Approach to Nuclear Collective Vibration