ICHEP 2024

The search for KL0→γ+darkphoton(γ¯) at the KOTO experiment.

18 Jul 2024, 11:19

17m

South Hall 1A

Parallel session talk 03. Beyond the Standard Model Beyond the Standard Model

Speaker

TONG WU (National Taiwan University)

Description

We present the study of the massless dark photon ($\overline{\gamma }$) in the $K_L^0\to \gamma \overline{\gamma }$ decay at the J-PARC KOTO experiment. Distinguished from the massive dark photon, the massless one does not directly mix with the ordinary photon but could interact with Standard Model (SM) particles through direct coupling to quarks. Some theoretical models propose that the branching ratio ($\mathcal{BR}$) of the $K_L^0\to \gamma \overline{\gamma }$ decay could reach up to $\mathcal{O}({10}^{-3})$, which is well within the KOTO's sensitivity for this study. Although the challenge is posed by the lack of kinematic constraints, the KOTO hermetic veto system provides a unique opportunity to probe for such decay. In this presentation, we will present the open-box result of the $K_L^0\to \gamma \overline{\gamma }$ search based on the data collected in 2020.

Presentation materials

20240718_ICHEP_v2_reduce.pdf