Eur. Phys. J. C (2019) 79: 369
https://doi.org/10.1140/epjc/s10052-019-6889-y

Regular Article - Theoretical Physics

Flavor constraints on electroweak ALP couplings

¹ Departamento de Física Teórica and Instituto de Física Teórica, IFT-UAM/CSIC, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain
² Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova, Padova, Italy
³ Istituto Nazionale Fisica Nucleare, Sezione di Padova, 35131, Padova, Italy

^* e-mail: olcyr.sumensari@pd.infn.it

Received: 23 January 2019
Accepted: 17 April 2019
Published online: 29 April 2019

Abstract

We explore the signals of axion-like particles (ALPs) in flavor-changing neutral current (FCNC) processes. The most general effective linear Lagrangian for ALP couplings to the electroweak bosonic sector is considered, and its contribution to FCNC decays is computed up to one-loop order. The interplay between the different couplings opens new territory for experimental exploration, as analyzed here in the ALP mass range GeV. When kinematically allowed, decays provide the most stringent constraints for channels with invisible final states, while B-meson decays are more constraining for visible decay channels, such as displaced vertices in data. The complementarity with collider constraints is discussed as well.