Are Unofficial Higgs Combinations Valid? Unofficial Higgs Discovery with 2011 Data and H --> WW Revisited

Abstract

At the CERN July 4^th press conference the Director General Dr. Rolf Heuer warned journalists about unofficial combinations. I agree with what he says. The unofficial combinations are approximate and should be used with caution. It is not just the correlations that are neglected but also it assumes that the statistical errors have a flat normal distribution. The detector collaborations don’t provide detailed likelihood data to outsiders. However, all statistical errors tend towards the normal Gaussian as the quantity of data increases (central limit theorem) and in most cases there is enough data for the results to be good, with a few exceptions. Indeed, using the unofficial combination on the 2011 data, I find that the LHC combination jumped from 3.67 sigma to 4.64 sigma while the global combination with all the 2011 data jumped from 4.4 sigma to 5.27 sigma. Even taking into account the error margins for the unofficial combination this means that the global combination has risen to discovery level significance level based on 2011 data alone, an impressive result. Finally, I revisit the Higgs to WW decay.