3-LOOP SPLITTING FUNCTIONS;
LEADING ORDER;
RENORMALIZATION-GROUP;
PARTON DENSITIES;
BETA-FUNCTION;
JET CALCULUS;
INTEGRATION;
QUARK;
ASYMPTOTICS;
EQUATIONS;
D O I:
10.1103/PhysRevLett.124.162001
中图分类号:
O4 [物理学];
学科分类号:
0702 ;
摘要:
We calculate the complete quark and gluon cusp anomalous dimensions in four-loop massless QCD analytically from first principles. In addition, we determine the complete matter dependence of the quark and gluon collinear anomalous dimensions. Our approach is to Laurent expand four-loop quark and gluon form factors in the parameter of dimensional regularization. We employ finite field and syzygy techniques to reduce the relevant Feynman integrals to a basis of finite integrals, and subsequently evaluate the basis integrals directly from their standard parametric representations.