KOTO

The KOTO experiment aims to discover and eventually measure roughly 100 events of the second order flavor changing neutral current reaction ΚL->π0νν, which will either establish more precise limits for the standard model or lead to new physics. The standard model predicts that this reaction will have a branching ratio of (3.0±0.4)x10-11, and will occur via direct charge-parity (CP) violation. Kaon decays are known examples of charge-parity (CP) violation. CP symmetry refers to the idea that there should be an equal amount of matter and antimatter (particles and antiparticles) in the universe, yet observations indicate that matter dominates. CP violation occurs when the probability of a particle's decay into other particles is different from the probability that its antiparticle will decay into the mirror antiparticles, so CP violation expected in this experiment should provide some insight into the imbalance between matter and antimatter. KOTO involves an international collaboration between numerous and takes place at the Japan Proton Accelerator Research Complex (JPARC) in Tokai, Japan. KOTO new results were published in Physical Review Letters establishing a new upper limit on the ΚL->π0νν decay.