# Synopsis: Using Topspin to Probe the Standard Model

#### Observation of Spin Correlation in tt̅ Events from pp Collisions at √s=7  TeV Using the ATLAS Detector

The top quark, because it is the most massive, provides a unique window into high-energy physics. For one thing, its decay releases energy that could uncover exotic processes that would otherwise be inaccessible. In addition, this decay is so fast, a fraction of a yoctosecond $\left({10}^{-24}\phantom{\rule{0.333em}{0ex}}\text{s}\right)$, that there is not enough time for the strong interaction to create more quarks that would obscure the original properties of the bare top quark. In Physical Review Letters, researchers analyze the decay of top quark-antiquark pairs from the ATLAS detector at the Large Hadron Collider to look for gaps in the standard model for particle physics. They found no gaps.