Speaker
Description
This talk would present a combination of searches for Higgs boson pair production using the ATLAS Run2 data sets. The upper limit on the production rate at 95% confidence level(CL) is 2.9 times the Standard Model (SM) prediction, with an expected limit of 2.4 assuming no Higgs boson pair production. Constraints on the Higgs boson self-coupling modifier,`$\kappa_{\lambda}=\lambda_{HHH}/\lambda_{HHH}^{SM}$, and quartic HHVV coupling modifier,$\kappa_{2V}=g_{HHVV}/g_{HHVV}^{SM}$, are derived individually, fixing the other parameter to its SM value. The observed constraints are $-1.2<\kappa_\lambda < 7.2$ and $0.57<\kappa_{2V}<1.48$ at 95% CL, with expected values of $-1.6<\kappa_\lambda < 7.2$ and $0.41<\kappa_{2V}<1.65$ in SM case. Strongest constraints to date are provided on several effective interactions within the Higgs Effective Field Theory, offering insights into potential deviations from SM predictions.
