论文标题
使用反应堆antineutrinos的$ \ sin^2θ_{13} $的次级精度测量
Towards a Sub-percent Precision Measurement of $\sin^2θ_{13}$ with Reactor Antineutrinos
论文作者
论文摘要
将中微子混合参数\ nesuremath {\ sin^2θ_{13}}到次级精度水平可能是必要的，以便在未来十年中，对于PMNS矩阵的精确统一测试。在这项工作中，我们讨论了反应堆抗神经纤维的可能性。我们发现，在合理规模的情况下，单个液体闪烁体检测器可以实现目标。我们建议将$ \ sim10 $ \％能量分辨率的检测器安装在距反应堆约2.0 km的情况下，并带有类似Juno的覆盖层。集成的光度要求约为150〜 $ {\ rm kton} \ cdot {\ rm gw} \ cdot {\ rm年} $，对应于9.2 gw themal power的4年操作，如9.2 gw themal power oferator。与以前的$θ_{13} $实验不同，具有相同近距离检测器的实验，这可以抑制系统的尤其是近FAR相对测量的速率不确定性，并且最佳基线处于第一个振荡最大值约1.8〜km的最大振荡，单端部门的测量值是单个轨道的测量值，以使基线从电动机最大化。在低统计数据$ \ lyssim 10 $〜$ {\ rm kton} \ cdot {\ rm gw} \ cdot {\ rm year as y y y y y y y lim y y} $，速率不确定性主导了系统，最佳基线约为1.3〜 km。在较高的统计数据下，光谱形状的不确定性变为主导，最佳基线转移到约2.0〜km。最佳基线一直是$ \ sim 2.0 $〜km，对于集成的光度，最高$ 10^6 $〜$ {\ rm kton} \ cdot {\ rm gw} \ cdot {\ rm year year} $。我们已经假设TAO实验将提高我们对光谱形状不确定性的理解，这给出了反应堆抗神经光谱的最高精度测量中微子能量，范围为3--6〜MEV。我们发现，最佳基线为$ \ sim 2.9 $〜km，其扁平输入光谱形状不确定性由未来的求和方法或转换方法的预测提供。
Measuring the neutrino mixing parameter \ensuremath{\sin^2θ_{13}} to the sub-percent precision level could be necessary in the next ten years for the precision unitary test of the PMNS matrix. In this work, we discuss the possibility of such a measurement with reactor antineutrinos. We find that a single liquid scintillator detector on a reasonable scale could achieve the goal. We propose to install a detector of $\sim10$\% energy resolution at about 2.0~km from the reactors with a JUNO-like overburden. The integrated luminosity requirement is about 150~${\rm kton}\cdot {\rm GW}\cdot {\rm year}$, corresponding to 4 years' operation of a 4~kton detector near a reactor complex of 9.2 GW thermal power like Taishan reactor. Unlike the previous $θ_{13}$ experiments with identical near and far detectors, which can suppress the systematics especially the rate uncertainty by the near-far relative measurement and the optimal baseline is at the first oscillation maximum of about 1.8~km, a single-detector measurement prefers to offset the baseline from the oscillation maximum. At low statistics $\lesssim 10$~${\rm kton}\cdot {\rm GW}\cdot {\rm year}$, the rate uncertainty dominates the systematics, and the optimal baseline is about 1.3~km. At higher statistics, the spectral shape uncertainty becomes dominant, and the optimal baseline shifts to about 2.0~km. The optimal baseline keeps being $\sim 2.0$~km for an integrated luminosity up to $10^6$~${\rm kton}\cdot {\rm GW}\cdot {\rm year}$. We have assumed that the TAO experiment will improve our understanding of the spectral shape uncertainty, which gives the highest precision measurement of reactor antineutrino spectrum for neutrino energy in the range of 3--6~MeV. We find that the optimal baseline is $\sim 2.9$~km with a flat input spectral shape uncertainty provided by the future summation or conversion methods' prediction.
