Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC

TL;DR

This paper reports the discovery of a new particle at 126 GeV consistent with the Standard Model Higgs boson, based on combined data from ATLAS at the LHC, with high statistical significance.

Contribution

First observation of a Higgs-like particle at 126 GeV using combined ATLAS data from 7 and 8 TeV runs, confirming the Standard Model prediction.

Findings

Discovery of a new boson at 126 GeV

Significance of 5.9 standard deviations

Compatible with Standard Model Higgs boson

Abstract

A search for the Standard Model Higgs boson in proton-proton collisions with the ATLAS detector at the LHC is presented. The datasets used correspond to integrated luminosities of approximately 4.8 fb^-1 collected at sqrt(s) = 7 TeV in 2011 and 5.8 fb^-1 at sqrt(s) = 8 TeV in 2012. Individual searches in the channels H->ZZ^(*)->llll, H->gamma gamma and H->WW->e nu mu nu in the 8 TeV data are combined with previously published results of searches for H->ZZ^(*), WW^(*), bbbar and tau^+tau^- in the 7 TeV data and results from improved analyses of the H->ZZ^(*)->llll and H->gamma gamma channels in the 7 TeV data. Clear evidence for the production of a neutral boson with a measured mass of 126.0 +/- 0.4(stat) +/- 0.4(sys) GeV is presented. This observation, which has a significance of 5.9 standard deviations, corresponding to a background fluctuation probability of 1.7x10^-9, is compatible with the production and decay of the Standard Model Higgs boson.