127 research outputs found
FMFT: Fully Massive Four-loop Tadpoles
We present FMFT - a package written in FORM that evaluates four-loop fully
massive tadpole Feynman diagrams. It is a successor of the MATAD package that
has been successfully used to calculate many renormalization group functions at
three-loop order in a wide range of quantum field theories especially in the
Standard Model. We describe an internal structure of the package and provide
some examples of its usage.Comment: Available for download from https://github.com/apik/fmft
Three-loop SM beta-functions for matrix Yukawa couplings
We present the extension of our previous results for three-loop Yukawa
coupling beta-functions to the case of complex Yukawa matrices describing the
flavour structure of the SM. The calculation is carried out in the context of
unbroken phase of the SM with the help of the MINCER program in a general
linear gauge and cross-checked by means of MATAD/BAMBA codes. In addition,
ambiguities in Yukawa matrix beta-functions are studied.Comment: 9 pages, references added, version accepted by PL
Three-loop vertex integrals at symmetric point
This paper provides details of the massless three-loop three-point integrals
calculation at the symmetric point. Our work aimed to extend known two-loop
results for such integrals to the three-loop level. Obtained results can find
their application in regularization-invariant symmetric point
momentum-subtraction (RI/SMOM) scheme QCD calculations of renormalization group
functions and various composite operator matrix elements. To calculate
integrals, we solve differential equations for auxiliary integrals by
transforming the system to the -form. Calculated integrals are
expressed through the basis of functions with uniform transcendental weight. We
provide expansion up to the transcendental weight six for the basis functions
in terms of harmonic polylogarithms with six-root of unity argument.Comment: 14 pages, many figure
Three-loop Higgs self-coupling beta-function in the Standard Model with complex Yukawa matrices
Three-loop renormalization group equations for the Higgs self-coupling and
Higgs mass parameter are recalculated in the case of complex Yukawa matrices,
which encompass general flavour structure of the Standard Model. In addition,
the anomalous dimensions both for the quantum Higgs field and its vacuum
expectation value are presented in the -scheme. A numerical
study of the latter quantities is carried out for a certain set of initial
parameters.Comment: 14 pages, 2 figures, report numbers added, figures redraw
Three-loop massive tadpoles and polylogarithms through weight six
We evaluate the three-loop massive vacuum bubble diagrams in terms of
polylogarithms up to weight six. We also construct the basis of irrational
constants being harmonic polylgarithms of arguments .Comment: 26 pages, 4 ancillary files, v3: version published in JHEP: minor
additions, file with results for massive three-loop form-factor integrals
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