Abstract
We derive partial-wave unitarity constraints on gauge-invariant interactions of an Axion-Like Particle (ALP) up to dimension-6 from all allowed $2\to2$ scattering processes in the limit of large center-of-mass energy. We find that the strongest bounds stem from scattering amplitudes with one external ALP and only apply to the coupling to a pair of $SU(2)_L$ gauge bosons. Couplings to $U(1)_Y$ and $SU(3)_C$ gauge bosons and to fermions are more loosely constrained.
Highlights
Axionlike particles (ALPs) are generic pseudoGoldstone bosons that can emerge from the spontaneous breaking of some global symmetry at energies well above the electroweak (EW) scale v
ALPs are usually studied within a model-independent effective field theory (EFT) framework [41,42]
Because these bounds are inversely proportional to the Yukawa coupling of the fermion and involve larger coefficients, we conclude that the unitarity constraints on the ALP-fermion couplings are orders of magnitude weaker than those on ALP–gauge boson couplings even for the coupling to the up quarks
Summary
Institució Catalana de Recerca i Estudis Avançats (ICREA), Departament d’Estructura i Constituents de la Materia, Universitat de Barcelona, 647 Diagonal, E-08028 Barcelona, Spain and C.N. Yang Institute for Theoretical Physics, SUNY at Stony Brook, Stony Brook, New York 11794-3840, USA (Received 25 June 2021; accepted 27 July 2021; published 27 August 2021). We derive partial-wave unitarity constraints on gauge-invariant interactions of an axionlike particle up to dimension-6 from all allowed 2 → 2 scattering processes in the limit of large center-of-mass energy. We find that the strongest bounds stem from scattering amplitudes with one external axionlike particle and only apply to the coupling to a pair of SUð2ÞL gauge bosons. Couplings to Uð1ÞY and SUð3ÞC gauge bosons and to fermions are more loosely constrained
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
