The Higgs Boson: what are the odds?

[popeyespappy]

Got it. Although I’m still trying to figure out what happened to this bump reported in the Tevatron data from earlier this year. Was it determined to be in error?



Or is it close enough to be consistant with this data?



If so does this still apply?

We have presented NLO predictions for cross sections and dijet invariant mass distributions for one lepton, missing ET and two jets at the Tevatron. We have used a variety of cuts, including those used by the CDF collaboration who have recently reported an excess in this distribution around 150 GeV. By calculating the distribution of the invariant mass of the dijets at NLO we have ruled out large NLO K-factors as a possible source of the excess within the context of the SM. At NLO the cross sections have only a moderate dependence on the renormalisation and factorisation scales of QCD, indicating that our results could be used to constrain the overall normalisation of these backgrounds.

The SM predicts a parton-level edge in the top background around 150 GeV, an edge that is softened into a broader peak by the parton shower. Detector effects, that we have not considered here, will certainly modify this feature further. In order to gain better control over the shape of this background we would advocate the use of the more inclusive cuts for which the top background is much larger and thus more easily constrained. It becomes even more significant for cuts demanding harder jets. For instance a pj T > 40 GeV cut yields a top cross section in the region of the broad peak only a factor of 2.5 lower than the W+ jets contribution. Further information on this background could be gleaned by investigating the dijet mass distribution for the case of b-tagged (or anti-tagged) jets. In particular, the dominant source of two anti-b-tagged jets is from the hadronic decay of the W. The invariant mass of two anti-b-tagged jets should therefore peak sharply around mW, with no significant peak in the 100–150 GeV region.