KOTO实验的长寿命中性K介子通量测量
Long-lived neutral-kaon flux measurement for the KOTO experiment
摘要：
KOTO（东海的$K^0$）实验旨在通过使用日本质子加速器研究综合体的30 GeV质子束产生的长寿命中性kaon束来观察CP违反的稀有衰变$K_L \rightarrow π^0 ν\barν$。$K_L$通量是测量支化分数的基本参数。在2013年KOTO工程运行中，三种$K_L$中性衰变模式（$K_L \rightarrow 3π^0$、$K_L \rightarrow 2π^0$和$K_L \rightarrow 2γ$）用于测量束线中的$K_L$通量。一个蒙特卡罗模拟被用来估计这些衰变的探测器接受。模拟模型与实验数据吻合较好，剩余的系统不确定度估计为1.4%。$K_L$通量测量为66 mm长Au靶上每$2\times 10^{14}$质子的$(4.183 \pm 0.017_{\mathrm{stat.}} \pm 0.059_{\mathrm{sys.}}) \times 10^7$ $K_L$。
英文摘要：
The KOTO ($K^0$ at Tokai) experiment aims to observe the CP-violating rare decay $K_L \rightarrow π^0 ν\barν$ by using a long-lived neutral-kaon beam produced by the 30 GeV proton beam at the Japan Proton Accelerator Research Complex. The $K_L$ flux is an essential parameter for the measurement of the branching fraction. Three $K_L$ neutral decay modes, $K_L \rightarrow 3π^0$, $K_L \rightarrow 2π^0$, and $K_L \rightarrow 2γ$ were used to measure the $K_L$ flux in the beam line in the 2013 KOTO engineering run. A Monte Carlo simulation was used to estimate the detector acceptance for these decays. Agreement was found between the simulation model and the experimental data, and the remaining systematic uncertainty was estimated at the 1.4\% level. The $K_L$ flux was measured as $(4.183 \pm 0.017_{\mathrm{stat.}} \pm 0.059_{\mathrm{sys.}}) \times 10^7$ $K_L$ per $2\times 10^{14}$ protons on a 66-mm-long Au target.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
