论文标题
搜索在微酮检测器中衰减的长寿命重中性瘦素和Higgs门户标量
Search for long-lived heavy neutral leptons and Higgs portal scalars decaying in the MicroBooNE detector
论文作者
论文摘要
我们提出了搜索长期寿命的Higgs门户标量（HPS）和在微体液体 - 阿贡时间投影室中衰减的重中性瘦素（HNL）。使用来自Fermilab的主要注射器的Numi Neutrino Beam同步收集的数据进行测量，总暴露量对应于目标上的$ 7.01 \ times 10^{20} $质子。我们将上限设置为$ 90 \％$的置信度$ \ lvert u_ {μ4} \ rvert^2 $，范围从$ \ lvert u_ {μ4} \ rvert^2 <12.9 \ 12.9 \ times times times times times times 10^{-8} $ for Majora hnls a cobs a me a $ m me m me} $ \ lvert u_ {μ4} \ rvert^2 <0.92 \ times 10^{ - 8} $ for $ m _ {\ rm hnl} = 385 $ meV，假设$ \ lvert u _ {e 4} \ rvert^\ rvert^\ rvert^2 = \ lvert^2 = \ lvert^\ lvert U_ { $μ^\pmπ^\ mp $对。与先前的微酮结果相比，这些限制在$ \ lvert u_ {μ4} \ rvert^2 $上表示灵敏度的提高顺序。我们还通过搜索hps衰减到$μ^+μ^ - $最终状态来限制标量higgs的混合角$θ$，在参数空间中排除了$θ^2 <31.3 \ times 10^{ - 9} $ $ m _ for $ m _ for $ m _ {\ rm hps} = 212 $ g^的参数空间中的轮廓。 10^{ - 9} $ for $ m _ {\ rm hps} = 275 $ gev。这些是从该质量范围的专用实验搜索中的标量higgs混合角$θ$的第一个约束。
We present a search for long-lived Higgs portal scalars (HPS) and heavy neutral leptons (HNL) decaying in the MicroBooNE liquid-argon time projection chamber. The measurement is performed using data collected synchronously with the NuMI neutrino beam from Fermilab's Main Injector with a total exposure corresponding to $7.01 \times 10^{20}$ protons on target. We set upper limits at the $90\%$ confidence level on the mixing parameter $\lvert U_{μ4}\rvert^2$ ranging from $\lvert U_{μ4}\rvert^2<12.9\times 10^{-8}$ for Majorana HNLs with a mass of $m_{\rm HNL}=246$ MeV to $\lvert U_{μ4}\rvert^2<0.92 \times 10^{-8}$ for $m_{\rm HNL}=385$ MeV, assuming $\lvert U_{e 4}\rvert^2 = \lvert U_{τ4}\rvert^2 = 0$ and HNL decays into $μ^\pmπ^\mp$ pairs. These limits on $\lvert U_{μ4}\rvert^2$ represent an order of magnitude improvement in sensitivity compared to the previous MicroBooNE result. We also constrain the scalar-Higgs mixing angle $θ$ by searching for HPS decays into $μ^+μ^-$ final states, excluding a contour in the parameter space with lower bounds of $θ^2<31.3 \times 10^{-9}$ for $m_{\rm HPS}=212$ GeV and $θ^2<1.09 \times 10^{-9}$ for $m_{\rm HPS}=275$ GeV. These are the first constraints on the scalar-Higgs mixing angle $θ$ from a dedicated experimental search in this mass range.
