Revisiting the production of ALPs at B-factories

Understand

In this paper, the production of Axion-Like Particles (ALPs) at $B$-factories via the process $e^+e^- \to \gamma a$ is revisited.

• To this purpose, the relevant cross-section is computed via an effective Lagrangian with simultaneous ALP couplings to $b$-quarks and photons.
• The interplay between resonant and non-resonant contributions is shown to be relevant for experiments operating at $\sqrt{s}=m_{\Upsilon(nS)}$, with $n=1,2,3$, while the non-resonant one dominates at $\Upsilon(4S)$.
• These effects imply that the experimental searches performed at different quarkonia resonances are sensitive to complementary combinations of ALP couplings.