showing 2 related works from this author
Effect ofmconbquark chromomagnetic interaction and on-shell two-loop integrals with two masses
1999
The effect of non-zero c quark mass on b quark HQET Lagrangian, up to 1/mb level, is calculated at two loops. The results are expressed in terms of dilogarithmic functions of mc/mb. This calculation involves on-shell two-loop propagator-type diagrams with two different masses, mb and mc. A general algorithm for reducing such Feynman integrals to the basis of two nontrivial and two trivial integrals is constructed.
Matter dependence of the four-loop QCD cusp anomalous dimension: from small angles to all angles
2019
We compute the fermionic contributions to the cusp anomalous dimension in QCD at four loops as an expansion for small cusp angle. As a byproduct we also obtain the respective terms of the four-loop HQET wave function anomalous dimension. Our new results at small angles provide stringent tests of a recent conjecture for the exact angle dependence of the matter terms in the four-loop cusp anomalous dimension. We find that the conjecture does not hold for two of the seven fermionic color structures, but passes all tests for the remaining terms. This provides strong support for the validity of the corresponding conjectured expressions with full angle dependence. Taking the limit of large Minkow…