Résumé |
Searching for deviations in quartic gauge boson couplings (QGCs) is one
of the main goals of the electroweak program at the LHC. We consider
positivity bounds adapted to the Standard Model EFT, and show that a set
of positivity constraints on 18 anomalous QGC couplings can be derived,
by requiring that the vector boson scattering amplitudes satisfy the
fundamental principles of quantum field theory. We solve the positivity
inequalities and find that the allowed parameter space is carved out by
the intersection of pyramids, prisms, and cones. Altogether, the allowed
parameter space is reduced to ~2% of total. These bounds provide
guidance to future BSM searches and could affect the limits on couplings
by modifying the prior. |