AI 中文总结
本研究利用NOvA近探测器测量μ子反中微子与氢的带电流准弹性散射总截面，通过拓扑与运动学约束筛选信号、专用控制样本压低重核本底，获迄今最高统计量与最精确截面结果，可用于约束束流流强。
AI 中文摘要
我们报道了在NOvA近探测器中，利用NuMI束流下$1.2\times10^{21}$的质子打靶曝光量，测量μ子反中微子与氢的带电流准弹性散射总截面$\bar ν_μ{\rm H} \to μ^+ n$的结果。基于拓扑与运动学约束的筛选方法，在富氢（$10.8\%$）探测器中得到35509个信号事例，提供了迄今测量到的最高统计量的（反）中微子-氢相互作用样本。来自重核上（反）中微子相互作用的本底通过专用数据控制样本进行约束，显著降低了相关的系统不确定度。我们在1.9 GeV的平均能量下得到总截面值为$σ(\bar ν_μ{\rm H} \to μ^+ n) = 0.538 \pm 0.009 ({\rm stat}) \pm 0.010 ({\rm syst}) \pm0.055 ({\rm flux}) \times 10^{-38}$ cm$^2$，这是迄今该过程最精确的总截面测量结果。统计不确定度与非流强系统不确定度的合成值比流强不确定度小四倍以上，使得该测量结果未来可用于约束绝对$\bar ν_μ$流强。
英文摘要
We report a measurement of the total cross section for muon antineutrino charged-current quasi-elastic scattering on hydrogen, $\bar ν_μ{\rm H} \to μ^+ n$, in the NOvA near detector using a $1.2\times10^{21}$ proton-on-target exposure in the NuMI beam. A selection based on topological and kinematic constraints yields 35,509 signal events in the hydrogen-rich ($10.8\%$) detector, providing the highest statistics of (anti)neutrino--hydrogen interactions measured to date. Backgrounds from (anti)neutrino interactions on heavier nuclei are constrained using dedicated data control samples, significantly reducing the related systematic uncertainties. We obtain a value $σ(\bar ν_μ{\rm H} \to μ^+ n) = 0.538 \pm 0.009 ({\rm stat}) \pm 0.010 ({\rm syst}) \pm0.055 ({\rm flux}) \times 10^{-38}$ cm$^2$ for the total cross section at an average energy of 1.9 GeV, the most precise total cross-section measurement of this process to date. The combined statistical and non-flux systematic uncertainty is more than four times smaller than the flux uncertainty, allowing a future use of this measurement to constrain the absolute $\bar ν_μ$ flux.
Comments11 pages (8 main and 3 supplemental), 10 figures (4 main and 6 supplemental)
