Prospects for HH measurements at the HL-LHC

The prospects for the study of Higgs boson pair production at the High-Luminosity LHC with the CMS detector are presented. Five decay channels, $\text{b}\text{b}\text{b}\text{b}$, $\text{b}\text{b}\text{W}\text{W}$, $\text{b}\text{b}\tau\tau$, $\text{b}\text{b}\gamma\gamma$, and $\text{b}\text{b}\text{Z}\text{Z}$, are studied. Analyses are developed using a parametric simulation of the upgraded detector response and optimised for a projected integrated luminosity of $3000\,\text{fb}^{-1}$. The statistical combination of the five decay channels results in an expected significance for the standard model $\text{HH}$ signal of $2.6\sigma$. Projections are also presented for the measurement of the Higgs boson self-coupling $\lambda_\text{HHH}$. The expected 68 and $95\%$ confidence level intervals for the coupling modifier $\kappa_\lambda = \lambda_\text{HHH} / \lambda_\text{HHH}^\text{SM}$ are $[0.35, 1.9]$ and $[-0.18, 3.6]$, respectively.