Consistent electroweak phenomenology of a nearly degenerate $Z^{\prime }$ boson

Journal Article · 03 February 2025 · Physical Review. D.

DOI: https://doi.org/10.1103/PhysRevD.111.035001 · OSTI ID:2510890

Lo Chiatto, Prisco ; Yu, Felix

Extracting constraints on the kinetic mixing of a new $U(1{)}^{\prime }$ gauge boson hiding under the Standard Model $Z$ boson resonance requires the formalism of non-Hermitian two-point correlation functions at 1-loop order. We derive self-consistent collider constraints on $Z^{\prime }$ bosons with kinetic mixing in a narrow mass window around the $Z$ boson, considering both model-independent and model-dependent bounds. Our treatment elucidates the importance of both avoided level crossing and the dispersive seesaw effect in interpreting the existing constraints. We also discuss the implications for future measurements on the $Z$ -pole. Published by the American Physical Society 2025

• Sponsoring Organization: USDOE
• OSTI ID: 2510890
• Journal Information: Physical Review. D., Journal Name: Physical Review. D. Journal Issue: 3 Vol. 111; ISSN PRVDAQ; ISSN 2470-0010
• Publisher: American Physical SocietyCopyright Statement
• Country of Publication: United States
• Language: English