NNLL QCD contribution of the electromagnetic dipole operator to image Original Research Article

We present an independent calculation of that part of the image contribution to the decay width image which arises from the self-interference term of the electromagnetic dipole operator image. Using a different method, we find complete agreement with a previous calculation. This NNLL contribution is an important ingredient for the complete NNLL prediction of image which will resolve the charm quark mass ambiguity appearing at NLL accuracy.