Effective QCD interactions of CP-odd Higgs bosons at three loops
| Autor: | K.G. Chetyrkin, Matthias Steinhauser, Bernd A. Kniehl, William A. Bardeen |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Quark
Quantum chromodynamics Physics Nuclear and High Energy Physics Particle physics Astrophysics::High Energy Astrophysical Phenomena High Energy Physics::Phenomenology FOS: Physical sciences Scalar boson Approx Massless particle High Energy Physics - Phenomenology High Energy Physics - Phenomenology (hep-ph) Virtual presence Physics::Space Physics Higgs boson Astrophysics::Solar and Stellar Astrophysics High Energy Physics::Experiment Boson |
| Zdroj: | Nuclear Physics B. 535:3-18 |
| ISSN: | 0550-3213 |
| Popis: | In the virtual presence of a heavy quark t, the interactions of a CP-odd scalar boson A, with mass M_A << 2M_t, with gluons and light quarks can be described by an effective Lagrangian. We analytically derive the coefficient functions of the respective physical operators to three loops in quantum chromodynamics (QCD), adopting the modified minimal-subtraction (MS-bar) scheme of dimensional regularization. Special attention is paid to the proper treatment of the gamma_5 matrix and the Levi-Civita epsilon tensor in D dimensions. In the case of the effective ggA coupling, we find agreement with an all-order prediction based on a low-energy theorem in connection with the Adler-Bardeen non-renormalization theorem. This effective Lagrangian allows us to analytically evaluate the next-to-leading QCD correction to the A -> gg partial decay width by considering massless diagrams. For M_A = 100GeV, the resulting correction factor reads 1+(221/12)alpha_s^(5)(M_A)/pi +165.9(alpha_s^(5)(M_A)/pi)^2 approx 1+0.68+0.23. We compare this result with predictions based on various scale-optimization methods. 17 pages (Latex), 2 figures (Postscript) |
| Databáze: | OpenAIRE |
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