******** NCTS/CTC/NTHU HEP Seminar ********

Speaker： Prof. Chih-Ting Liu (Nanjing Normal University)

Title ： Lighting Electroweak-Violating ALP-Lepton Interactions at e+e− and ep Colliders

Time ： 10:00-11:00, Wednesday, 2023/7/19

Place ： P512, 5F, 3rd General Building, Nat'l Tsing Hua Univ.

Host ： Prof. Po-Yen Tseng (NTHU)

Abstract:
A new type of four-point interaction, W-l-nu-a, in an electroweak-violating scenario of axion-like particle (ALP) and lepton interactions plays a critical role in searching for ALPs from charged mesons and W boson decays because of the novel energy enhancements. Inspired by this interesting finding, we first proposed new t-channel processes for electrophilic ALPs (eALPs) which also involve W-l-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 eALPs 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 eALPs 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.