Measuring the trilinear Higgs boson self--coupling at the 100 TeV hadron collider via multivariate analysis
Abstract
We perform a multivariate analysis of Higgs-pair production via the decay channel HH b b γγ at the future 100 TeV pp collider to determine the trilinear Higgs self--coupling (THSC) λ3H, which takes the value of 1 in the standard model. We consider all known background processes. For the signal we adopt the most recent event generator of POWHEG-BOX-V2 to exploit the NLO distributions for Toolkit for Multivariate Data Analysis (TMVA). Through the technique of Boosted Decision Tree (BDT) analysis trained for λ3H=1, compared to the the conventional cut-and-count approach, the signal-to-background ratio improves tremendously from about 1/10 to 1 and the significance can reach up to 20.5 with a luminosity of 3 ab-1 without including systematic uncertainties. In addition, by implementing a likelihood fitting of the signal-plus-background Mγγ b b distribution with optimized bin sizes, it is possible to determine the THSC with the precision of 7.5\% at 68\% CL even at the early stage of 100 TeV hadron collider with 3 ab-1.