Estimate of the threeloop MS contribution to σ(W_{L}^{+}W_{L}^{ }>Z_{L}Z_{L})
Abstract
The threeloop contribution to the MS singleHiggsdoublet standardmodel crosssection σ(W_{L}^{+}W_{L}^{} >Z_{L}Z_{L}) at s=(5M_{H})^{2} is estimated via leastsquares matching of the asymptotic Padéapproximant prediction of the next order term, a procedure that has been previously applied to QCD corrections to correlation functions and decay amplitudes. In contrast to these prior applications, the expansion parameter for the W_{L}^{+}W_{L}^{} >Z_{L}Z_{L} process is the nonasymptoticallyfree quartic scalarfield coupling of the standard model, suggesting that the leastsquares matching be performed over the ``infrared'' μ^{2}<=s region of the scale parameter. All three coefficients of logarithms within the threeloop term obtained by such matching are found to be within 6.6% relative error of their true values, as determined via renormalizationgroup methods. Surprisingly, almost identical results are obtained by performing the least squares matching over the μ^{2}>=s region.
 Publication:

Physics Letters B
 Pub Date:
 February 2001
 DOI:
 10.1016/S03702693(01)000077
 arXiv:
 arXiv:hepph/0008319
 Bibcode:
 2001PhLB..499..270C
 Keywords:

 High Energy Physics  Phenomenology
 EPrint:
 9 pages, LaTeX, 3 figures added