Top tagging: a method for identifying boosted hadronically decaying top quarks.

A method is introduced for distinguishing top jets (boosted, hadronically decaying top quarks) from light-quark and gluon jets using jet substructure. The procedure involves parsing the jet cluster to resolve its subjets and then imposing kinematic constraints. With this method, light-quark or gluon jets with p{T} approximately 1 TeV can be rejected with an efficiency of around 99% while retaining up to 40% of top jets. This reduces the dijet background to heavy tt[over ] resonances by a factor of approximately 10 000, thereby allowing resonance searches in tt[over ] to be extended into the all-hadronic channel. In addition, top tagging can be used in tt[over ] events when one of the top quarks decays semileptonically, in events with missing energy, and in studies of b-tagging efficiency at high p{T}.

介绍了一种利用喷注子结构区分顶夸克喷注（加速的、强子衰变的顶夸克）与轻夸克和胶子喷注的方法。该过程包括解析喷注簇以分辨其子喷注，然后施加运动学约束。利用这种方法，对于横动量$p_T$约为1 TeV的轻夸克或胶子喷注，可以有约99%的效率将其排除，同时保留多达40%的顶夸克喷注。这使得重$t\bar{t}$共振的双喷注背景降低了约10000倍，从而使$t\bar{t}$中的共振搜索能够扩展到全强子通道。此外，在一个顶夸克半轻子衰变的$t\bar{t}$事件中、在有丢失能量的事件中以及在高$p_T$下的b标记效率研究中，都可以使用顶标记。