Updates tagged: “top quark”
The production of top quarks in association with vector bosons is a hot topic at the LHC. ATLAS first reported strong evidence for the production of a top quark in association with a Z boson at the EPS 2017 conference. In a paper submitted to the Journal of High-Energy Physics, the ATLAS experiment describes the measurement of top-quark production in association with a W boson in 13 TeV collisions.
Using Run 1 data, ATLAS reports a new differential production rate measurement of top quark pairs and a precise new determination of the top quark mass.
Ordinary matter is made of just three kinds of elementary particles: up and down quarks, which form the atomic nucleus, and electrons, which surround the nucleus. But the rest of nature is not so straightforward: heavier forms of quarks and leptons are produced regularly at particle accelerators.
The top quark, the heaviest known elementary particle, has a unique place in the Standard Model. By precisely measuring its properties, ATLAS physicists can probe physics beyond our current understanding.
The ATLAS collaboration presented exciting new results at the 10th International Workshop on Top Quark Physics (TOP2017), held in Braga (Portugal). The conference, which concluded today, brought together experimental and theoretical physicists specializing in the heaviest known elementary particle: the top quark.
For the first time, ATLAS has measured the kinematics of the top quark and of the tt̅ system in 13 TeV events containing two charged leptons, two neutrinos and two jets (called “dilepton” events).
The ATLAS experiment has been searching for the process in which a pair of top quarks is produced, where one is a “virtual” particle that emits a Higgs boson on the way to becoming a “real” particle. This process is referred to as ttH production after the particles that are produced.
ATLAS has released a new precise measurement of the mass of the top quark, the heaviest known elementary particle.
The top quark conference normally follows the same basic structure. The first few days are devoted to reports on the general status of the field and inclusive measurements; non-objectionable stuff that doesn’t cause controversy. The final few days are given over to more focused analyses; the sort of results that professors really enjoy arguing about.
This week, physicists from around the world are gathering at the Top 2015 workshop in Ischia, Italy to discuss the latest measurements of the top quark. As the heaviest known fundamental particle, the top quark plays a special role in the search for "new physics".