During my professional career as a clinician for nearly five decades, I have come across several instances where felt that role has been failure. consider these critical incidents molded clinical practice and hopefully made me better clinician. In this paper, will discuss about few of those situations, narrating the experience lived through, highlighting think went wrong how best we clinicians ...

The background field approach to multi-loop calculations in gauge field theories is presented. A relation between the gauge-invariant effective action computed using this method and the effective action of the conventional functional approach is derived. Feynman rules are given and renormalization is discussed. It is shown that the renormalization programme can be carried out without any refere...

This talk presents details of the calculation of two-loop corrections to heavy baryon currents containing one heavy quark in leading order of the 1/mQ-expansion, i.e. in the limit of Heavy Quark Symmetry (HQS). The calculations lead to the determination of the anomalous dimension of these currents. I also discuss problems with different γ5-schemes and their solution by the finite renormalizatio...