an:06663252
Zbl 1351.81006
Degrande, Celine
Automatic evaluation of UV and \(R_2\) terms for beyond the standard model Lagrangians: a proof-of-principle
EN
Comput. Phys. Commun. 197, 239-262 (2015).
0010-4655
2015
j
81-04 81T18 81-08
BSM; automated one-loop computation; ultraviolet counterterms; rational terms
Summary: The computation of renormalized one-loop amplitudes in quantum field theory requires not only the knowledge of the Lagrangian density and the corresponding Feynman rules, but also that of the ultraviolet counterterms. More in general, and depending also on the method used in the actual computation of the one-loop amplitudes, additional interactions might be needed. One example is that of the \(R_2\) rational terms in the OPP method. In this paper, we argue that the determination of all elements necessary for loop computations in arbitrary models can be automated starting only from information on the Lagrangian at the tree-level. In particular, we show how the \(R_2\) rational and ultraviolet counterterms for any renormalizable model can be computed with the help of a new package, which we name NLOCT and builds upon \textsc{FeynRules} and \textsc{FeynArts}. To show the potential of our approach, we calculate all additional rules that are needed to promote a Two Higgs Doublet Model Lagrangian to one-loop computations in QCD and electroweak couplings.