Normalization Study for the Search for K_L->π⁰νν with the KOTO Experiment

The KOTO Experiment at the J-PARC research facility in Tokai, Japan aims to observe and measure the rare decay of the neutral kaon, K_L->π⁰νν. This decay has a Standard Model (SM) predicted branching ratio (BR) of (3.00 ± 0.30) × 10^-11 which is why it has never been observed before. While this decay is extremely rare, it is one of the best decays for studying CP violation in the quark sector because it is a clean channel with small theoretical uncertainties. The experiment E391a previously searched for K_L->π⁰νν events and set a limit of BR(K_L->π⁰νν) < 2.6 × 10^-8 in 2010. The KOTO Experiment set a new experimental limit in 2018 for the branching ratio of K_L->π⁰νν from data collected in 2015. From 2016 to 2018, KOTO collected four times more data than in 2015, and this data set is currently being analyzed. A critical part of the analysis includes a detailed study of the normalization modes, K_L->3π⁰, K_L->2π⁰, and K_L->2γ, which are used to calculate the K_L flux and kinematic and veto cut efficiencies. This talk will focus on the 2016-2018 data and the analysis results of the normalization modes.