The compatibility of LHC Run 1 data with a heavy scalar of mass around 270\,GeV

Abstract

The first run of the LHC was successful in that it saw the discovery of the elusive Higgs boson, a particle that is consistent with the SM hypothesis. There are a number of excesses in Run 1 ATLAS and CMS results which can be interpreted as being due to the existence of another heavier scalar particle. This particle has decay modes which we have studied using LHC Run 1 data. Using a minimalistic model, we can predict the kinematics of these final states and compare the prediction against data directly. A statistical combination of these results shows that a best fit point is found for a heavy scalar having a mass of 272${}_{-9}^{+12}$\,GeV. This result has been quantified as a three sigma effect, based on analyses which are not necessarily optimized for the search of a heavy scalar. The smoking guns for the discovery of this new heavy scalar and the prospects for Run 2 are discussed.

When first manuscript was submitted a number of experimental Run I results were not avaiable. In this new version of the manuscript a complete set of Run I experimental results has been analyzed in a global fit. More attention has been paid to the gauge invariance of the Lagrangian, leading to a discussion on an intermediate real particle. The list of smoking gun final states has been expanded