Low-energy flavour probes of light vector bosons

• DOI: 10.48550/arxiv.2309.07052
• Publication Date: 2023-01-01
• Authors: Luca Di Luzio; Gabriele Levati; Paride Paradisi; Xavier Ponce Díaz
• Keywords: Flavour; Vector boson

In this work, we construct the chiral Lagrangian for a light spin-1 boson $X$ possessing both vectorial and axial couplings to Standard Model quarks $u, d, s$. We then use it in order describe tree-level, model-independent contributions $\Delta S = 1$ transition $K^\pm \rightarrow \pi^\pm X$, which is induced by charged currents possibly enhanced emission of longitudinally polarized boson. Such flavour observable shown set best bounds on diagonal mass range allowed decay kinematics, improving currently available constraints from beam-dump experiments collider searches.