Decoupling relations, effective Lagrangians and low-energy theorems

dc.creatorKniehl, B. A.
dc.date1998-11-25
dc.date.accessioned2026-07-07T04:05:50Z
dc.date.available2026-07-07T04:05:50Z
dc.descriptionIf QCD is renormalized by minimal subtraction (MS), at higher orders, the strong coupling constant alpha_s and the quark masses m_q exhibit discontinuities at the flavour thresholds, which are controlled by so-called decoupling constants, zeta_g and zeta_m, respectively. Adopting the modified MS (MS-bar) scheme, we derive simple formulae which reduce the calculation of zeta_g and zeta_m to the solution of vacuum integrals. This allows us to evaluate zeta_g and zeta_m through three loops. We also establish low-energy theorems, valid to all orders, which relate the effective couplings of the Higgs boson to gluons and light quarks, due to the virtual presence of a heavy quark h, to the logarithmic derivatives w.r.t. m_h of zeta_g and zeta_m, respectively. We also consider the effective QCD interaction of a CP-odd Higgs boson and verify the Adler-Bardeen nonrenormalization theorem at three loops.
dc.description10 pages (Latex), 4 figures (Postscript), 1 style file, to appear in the Proceedings of the IVth International Symposium on Radiative Corrections (RADCOR 98), Barcelona, Spain, 8-12 September 1998, edited by J. Sola
dc.identifierhttps://arxiv.org/abs/hep-ph/9811466
dc.identifierhttp://arxiv.org/abs/hep-ph/9811466
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/48551
dc.subjectHigh Energy Physics - Phenomenology
dc.titleDecoupling relations, effective Lagrangians and low-energy theorems
dc.typetext

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