Speaker
Description
In this talk, we report the first complete results of the four-loop non-singlet splitting functions in QCD. Splitting functions govern the scale evolution of parton distribution functions, which enter the theoretical predictions for all physical processes at high-energy hadron colliders. According to their flavor group structure, splitting functions are classified into non-singlet and singlet components. In the non-singlet case, a direct multiplicative renormalization formula applies, leaving the integration-by-parts (IBP) reduction and the solution of master integrals as the primary bottleneck. After many years of effort, we obtained recently the first complete four-loop non-singlet splitting functions. The results are in fully analytic form. We also report on progress in the singlet case, where twist-two operators mix with un-physical operators. We present a systematic procedure to derive the counterterm Feynman rules for these un-physical operators, which provides a path toward the complete four-loop singlet splitting functions.
| 请选择分会 | TeV物理和超出标准模型新物理 |
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