ATLAS searches for di-Higgs production at 13 TeV and prospects for HL-LHC

The latest results on production of Higgs boson pairs at 13 TeV by the ATLAS experiment are reported, including a combination of six different decay modes. Results include $b\bar{b}\tau^{-}\tau^{+}$, $b\bar{b}b\bar{b}$, $b\bar{b}\gamma\gamma$, $b\bar{b}WW$, $WWWW$ and $WW\gamma\gamma$ final states, and they are interpreted both in terms of sensitivity to the SM and as limits on $\kappa_{\lambda}$, a scaling of the triple-Higgs interaction strength. The most stringent constraint on di-Higgs production cross-section is set as 6.9 times SM cross-section and the $\kappa_{\lambda}$ is constrained in from -5.0 to 12 with 95% CL. A new search dedicated to the Vector-Boson-Fusion production was performed in the $b\bar{b}b\bar{b}$ final state. No significant excess, relative to the background-only Standard Model expectation, is observed and interpretation in terms of the coupling between a Higgs boson pair and two vector bosons is also provided: coupling values normalized to the Standard Model expectation of $\kappa_{2V} < -0.58$ and $2.89 < \kappa_{2V}$ are excluded at the 95% confidence level in data. Future prospects of testing the Higgs self-couplings at the High Luminosity LHC (HL-LHC) are also reported.