Higher-order corrections in the SM Higgs sector: the right scale

Abstract

The evaluation of high-energy cross sections involving the SM Higgs boson requires the use of the Higgs running coupling $\lambda (\mu )$. Taking $\mu$ to be equal to the center-of-mass energy $\sqrt{s}$ of the scattering process, the perturbative approach fails for relatively small values of the Higgs mass and coupling, $\lambda (\sqrt{s})\approx 2.2$. Performing an approximate resummation of ``bubble'' Feynman diagrams, we find the scale $\mu =\sqrt{s}/e\approx \sqrt{s}/2.7$ to yield reliable perturbative results, even for large Higgs mass and coupling. The new perturbative upper limit on the Higgs running coupling is $\lambda (\sqrt{s}/e)\approx 4$.

Comments: 6 pages, two-column style (espcrc2.sty), using LaTeX2e. The complete paper including figures is also available via WWW at http://www.physik.tu-muenchen.de/tumphy/d/T30d/PAPERS/TUM-HEP-249-96.ps.gz To appear in the Proceedings of the Workshop ``QCD and QED in Higher Order'', Rheinsberg, Germany (April 1996), edited by J. Blümlein, F. Jegerlehner, and T. Riemann