Independent evaluation of the significance of the recent ATLAS and CMS data

TL;DR

This paper provides an independent assessment of the statistical significance of recent ATLAS and CMS Higgs search data, using simplified analysis methods to evaluate the potential for external validation of the results.

Contribution

It introduces a simplified profile likelihood approach to independently evaluate the significance of Higgs search data without reproducing complex collaboration procedures.

Findings

Independent significance estimates align with collaboration reports.

Simplified analysis can approximate key statistical results.

Highlights challenges of external validation in complex experimental analyses.

Abstract

This note describes an independent assessment of the statistical significance of the recently released ATLAS and CMS data, about 11 fb-1 per experiment acquired in 2011 and in the first part of 2012, for what concerns the Higgs search in the two high resolution decay channels especially suited for the low mass region, i.e. the diphoton and four-lepton decay channels. Scope of this note is not to reproduce the analysis of the Collaborations: this would be impossible given the enormous complexity of the complete profile likelihood procedure used to evaluate local and global the p-values, and the huge number of nuisance parameters which are used to incorporate the numerous systematic effects. Rather, its purpose is to show the significance that an outsider can infer only on the basis of the released data and plots, used as input of a simplified profile likelihood procedure in which the only contemplated nuisance parameter is the background normalization in the diphoton channel. In practice, this note tries to address the question of the independent judgment of the significance of new data that physicists are used to perform on their own when they are shown for the first time particularly relevant results with indication of new effects, and that in the complex LHC framework is not so easily doable as in other experimental contexts.