Nonresonant Axion-Like Particle Searches at the LHC: Implications for Vector Boson Scattering

We discuss nonresonant axion-like particle (ALP) searches in diboson production at the LHC, a collider probe for ALPs which takes advantage of the derivative nature of their interactions with Standard Model particles; here ALPs participate as off-shell mediators in the scattering process. The power of this novel type of search has been tested with gluon-initiated diboson nonresonant production processes, using CMS and ATLAS Run 2 data, probing previously unexplored areas of the ALP parameter space. In addition, new studies on nonresonant ALP-mediated vector boson scattering (VBS) and preliminary results based on recently published CMS data are presented. Expectations for LHC Run 3 and HL-LHC are derived.