论文标题
从顶部的阿尔卑斯
The ALPs from the Top: Searching for long lived axion-like particles from exotic top decays
论文作者
论文摘要
我们建议在异国情调的顶级衰减中搜索长期存在的轴突样颗粒（阿尔卑斯山）。对于各种新物理场景，例如T通道黑暗扇区或Froggatt-Nielsen模型，风味侵略的阿尔卑斯山似乎是低能效率理论。在这种情况下，顶级夸克可能会腐烂到ALP和Up-或Charm-Quark。对于少数GEV范围内的群众，ALP长期居住在大多数可行的参数空间中，这表明是专门的搜索。我们建议在$ t \ bar {t} $事件中搜索这些长期活的阿尔卑斯山，以一个顶级夸克作为触发器。我们专注于辐射量热仪中的阿尔卑斯山衰减，并表明电磁和辐射量热计中的能量沉积物以及轨道否决者可以有效抑制标准模型背景。我们提出的搜索可以在即将到来的LHC运行中使用保守的策略来探测小于$ 10^{ - 4} $小于$ 10^{ - 4} $的探测，并且可能低于$ 10^{ - 7} $ latver live like Advanced方法。最后，我们还表明，在$ 10^{ - 3} $级别上，单个顶级生产探测到这些分支比率的测量值。
We propose a search for long lived axion-like particles (ALPs) in exotic top decays. Flavour-violating ALPs appear as low energy effective theories for various new physics scenarios such as t-channel dark sectors or Froggatt-Nielsen models. In this case the top quark may decay to an ALP and an up- or charm-quark. For masses in the few GeV range, the ALP is long lived across most of the viable parameter space, suggesting a dedicated search. We propose to search for these long lived ALPs in $t\bar{t}$ events, using one top quark as a trigger. We focus on ALPs decaying in the hadronic calorimeter, and show that the ratio of energy deposits in the electromagnetic and hadronic calorimeters as well as track vetoes can efficiently suppress Standard Model backgrounds. Our proposed search can probe exotic top branching ratios smaller than $10^{-4}$ with a conservative strategy at the upcoming LHC run, and potentially below the $10^{-7}$ level with more advanced methods. Finally we also show that measurements of single top production probe these branching ratios in the very short and very long lifetime limit at the $10^{-3}$ level.
