Lighting Electroweak-Violating ALP-Lepton Interactions at $e^{+}{e}^{-}$ and $ep$ Colliders

Abstract

Recently, Altmannshofer, Dror and Gori (2022) claimed there is a four-point interaction, $W$-$\ell$-$\nu$-$a$, in the electroweak-violating scenario of axion-like particle (ALP) and lepton interactions which plays a critical role in searching for ALPs from ${\pi }^{\pm }$, $K^{\pm }$ mesons and $W$ boson decays because of the novel energy enhancements. Inspired by this interesting finding, we first propose new t-channel processes, $e^{+}{e}^{-}\to {\nu }_{e}a\overline{{\nu }_e}$ and $e^{-}p\to {\nu }_{e}aj$, for electrophilic ALPs ($e$ALPs) which also involve $W$-$\ell$-$\nu$-$a$ four-point interaction and have obvious energy enhancement behaviors in their cross sections when the collision energy is increasing. On the other hand, heavier $e$ALPs mainly decay to a photon pair induced by the chiral anomaly instead of an electron-positron pair. Therefore, studies of these t-channel processes with a photon pair plus missing energy at $e^{+}{e}^{-}$ and $ep$ colliders open a new door to search for $e$ALPs at high energy colliders. The proposed search strategies are not only aiming to generate a larger production rate of ALPs, but also trying to distinguish electroweak-violating ALP-lepton interactions from electroweak-preserving ones.

Comments: 17 pages, 13 figures, 5 tables, version accepted by PRD