Speaker
Description
A SM extension with a light Axion-like Particle (ALP) in a large mass range can be parametrised in terms of a linear ALP-EFT, which couples the ALP to SM particles through momentum-dependent dimension-5 operators.
These interactions can lead to distinctive signatures in various processes at collider experiments such as the LHC.
Couplings of ALPs to SM fermions, in particular to top quark, can be probed by reinterpreting SM LHC measurements and assuming the ALP collider stable.
In this talk, I will focus on multiboson production, where the ALP appears as an off-shell mediator rather than a narrow resonance and assume that the ALP couples only to the gauge sector of the SM.
I then present the first global analysis of ALP-mediated multiboson processes, combining measurements of diphoton, ZZ, W+W−, dijet, and vector-boson–fusion final states.
Using Run-2 LHC measurements, bounds can be cast on the Wilson coefficients (cG, cW , cB) that parametrise gluonic and electroweak ALP interactions.