Status and Prospects of $K\rightarrow\pi\nu\bar{\nu}$ at NA62 and KOTO
The ultra-rare $K\rightarrow\pi\nu\bar{\nu}$ decays are considered golden modes in flavour physics. The charged $K^{+}\rightarrow\pi^{+}\nu\bar{\nu}$ decay mode is under investigation by the NA62 fixed-target experiment at CERN. NA62 collected the world's largest dataset of charged kaon decays in 2016-2018, leading to the first measurement of the branching ratio BR($K^{+}\rightarrow\pi^{+}\nu\bar{\nu}$) based on 20 signal candidates. This provides evidence for the ultra-rare $K^{+}\rightarrow\pi^{+}\nu\bar{\nu}$ decay, observed with a significance of $3.4\sigma$. NA62 restarted operation in 2021, and will continue taking data until CERN long shutdown 3, with the main goal of improving the precision on the measurement of BR($K^{+}\rightarrow\pi^{+}\nu\bar{\nu}$). The search for the neutral $K_{L}\rightarrow\pi^{0}\nu\bar{\nu}$ mode is currently being addressed by the KOTO experiment, located at the J-PARC accelerator complex in Japan. KOTO is expected to reach the Standard Model sensitivity for the $K_{L}\rightarrow\pi^{0}\nu\bar{\nu}$ decay in three to four years of data taking. The status of and prospects for $K\rightarrow\pi\nu\bar{\nu}$ measurements at NA62 and KOTO experiments are reviewed.
Authors
- A. Romano (ORCID: https://orcid.org/0000-0003-1779-9122)
Publication Details
- Published
- 2024-11-07
- DOI
- https://doi.org/10.22323/1.443.0050
- Primary Topic
- Superconducting Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 0.00