A joint Fermilab/SLAC publication

Europe reaches the top, err, the top reaches Europe

07/23/10

It might be a long way to the top, but the LHC experiments are already half-way there. Today at the International Conference on High Energy Physics in Paris, the CMS and ATLAS experiments presented their first top quark candidates. These candidates are collisions that have all the hallmarks of having produced top quarks, but the experiments don't yet have enough data to be 100% sure that the events created top quarks that decayed into other particles, rather than another type of event.

"The signal is starting to rise from the background," notes Tim Christiansen from CMS.

The top quark, the heaviest particle in the Standard Model, was discovered at Fermilab's Tevatron in 1995. The CDF and DZero experiments on the Tevatron are still busy measuring its properties in detail (one of this morning's parallel sessions had several talks on its width, mass and likely couplings to particles of and beyond the Standard Model). Now the LHC experiments are joining them on the way to explore the top: both CMS and ATLAS showed selected candidate events of top quark pairs.

Finding top quarks at the LHC is exciting because the top is the last, and heaviest, particle that the LHC needed to add to its list of 'rediscoveries'. It is also an important partner in the hunt for all sorts of new physics. The better the top and its behavior are understood the easier it will be to distinguish events that involve direct top quark production from events that involve, for example, the Higgs or supersymmetric particles.

The top at ATLAS?

The top at ATLAS?

The top at CMS?

The top at CMS?

Latest news articles
05/18/22
Sky & Telescope

Astronomers connect the dots between two strange doppelganger galaxies, uncovering what might be a string of galactic pearls created in a cosmic collision 8 billion years ago.

05/12/22
Event Horizon Telescope

The result provides overwhelming evidence that the object is indeed a black hole and yields valuable clues about the workings of such giants, which are thought to reside at the center of most galaxies.

05/10/22
Scientific American

THESAN—the largest, most detailed computer model of the universe’s first billion years yet made—is helping set expectations for observations from NASA’s James Webb Space Telescope.

05/05/22
Quanta

Theoretical physicist Sean Carroll discusses the quest for quantum gravity with host Steven Strogatz.