Probing the Higgs self-coupling through double Higgs production in vector boson scattering at the LHC

In this work we explore the sensitivity to the Higgs self-coupling λ in the production of two Higgs bosons via vector boson scattering at the LHC. Although these production channels, concretely W+W−→HH and ZZ→HH, have lower rates than gluon-gluon fusion, they benefit from being tree level processes, being independent of top physics and having very distinctive kinematics that allow us to obtain very clean experimental signatures. This makes them competitive channels concerning the sensitivity to the Higgs self-coupling. In order to give predictions for the sensitivity to this coupling, we first study the role of λ at the subprocess level, both in and beyond the Standard Model, to move afterwards to the LHC scenario. We characterize the pp→HHjj case first and then provide quantitative results for the values of λ that can be probed at the LHC in vector boson scattering processes after considering the Higgs boson decays. We focus mainly on pp→bb¯bb¯jj, since it has the largest signal rates, and also comment on the potential of other channels, such as pp→bb¯γγjj, as they lead to cleaner, although smaller, signals. Our whole study is performed for a center of mass energy of s=14TeV and for various future expected LHC luminositiesThis work is supported by the European Union through the ITN ELUSIVES H2020-MSCA-ITN-2015//674896 and the RISE INVISIBLESPLUS H2020-MSCA-RISE-2015//690575, by the CICYT through the projects FPA2016-78645-P, by the Spanish Consolider-Ingenio 2010 Programme CPAN (CSD2007-00042) and by the Spanish MINECO's “Centro de Excelencia Severo Ochoa” Programme under grant SEV-2016-0597. This work has also been partially supported by CONICET and ANPCyT projects no. PICT 2016-0164 and no. PICT-2017-2765 (E.A.