Jul 6 – 13, 2022
Bologna, Italy
Europe/Rome timezone

Search for a massless dark photon in KL→γ+dark photon at the KOTO experiment

Jul 8, 2022, 7:05 PM
1h 25m
Bologna, Italy

Bologna, Italy

Palazzo della Cultura e dei Congressi
Poster Dark Matter Poster Session


Tong Wu (National Taiwan University)


We present the study of the massless dark photon in the $K_{L}^{0}\rightarrow\gamma\bar\gamma$ decay at the J-PARC KOTO experiment. The massless dark photon ($\bar\gamma$) is different from the massive one because it has no direct mixing with the ordinary photon, but it could interact with the SM particles through direct coupling to the quarks. In some theoretical predictions, the $\mathcal{BR}(K_{L}^{0}\rightarrow\gamma\bar\gamma)$ can be as large as $\mathcal{O}(10^{-3})$, which is well within the sensitivity of KOTO. Although the search for $K_{L}^{0}\rightarrow\gamma\bar\gamma$ could be challenging due to the lacking kinematic constraints, the hermetic veto system of KOTO provides a unique opportunity to probe for such decay. In this presentation, we will present the study of $K_{L}^{0}\rightarrow\gamma\bar\gamma$ based on the data collected in 2020.

In-person participation No

Primary authors

Tong Wu (National Taiwan University) Yee Hsiung (National Taiwan University) Yu-Chen Tung (National Taiwan University)

Presentation materials