The top quark is the heaviest known elementary particle, as small as an electron but 340,000 times more massive! We don’t know how small those particles are, only that they are smaller than 1/1000th the size of a proton which itself is 1/100,000th the size of the smallest atom, hydrogen. Millionths, billionths, … soon we’re talking small numbers!
Twenty-five years ago, scientists on the CDF and DZero particle physics experiments at Fermilab announced one of history’s biggest breakthroughs in particle physics: the discovery of the long-sought top quark. The collaborations on the two experiments jointly made the announcement on March 2, 1995, to much fanfare. We take a look back on this day in Fermilab history a quarter-century ago.
From CERN, Oct. 7, 2019: The CMS collaboration has measured for the first time the variation, or “running,” of the top quark mass. The theory of quantum chromodynamics predicts this energy-scale variation for the masses of all quarks and for the strong force acting between them. Observing the running masses of quarks can therefore provide a way of testing quantum chromodynamics and the Standard Model.
From Duke Today, July 17, 2019: Teams behind the 1995 discovery are recognized for first observations of tiny but hefty particle at the heart of matter.
From Live Science, Feb. 5, 2019: This article dives deep into the little teensy tiny particles that are fundamental building blocks of matter. As far as scientists can tell, quarks themselves are not made of anything smaller. That may change in the future as we learn more, but it’s good enough for now.
From Listverse, Feb. 5, 2019: This listicle mentions Fermilab scientist Melissa Franklin as part of the Fermilab team that discovered the top quark.
From Scientific American, June 6, 2018: Fermilab’s Don Lincoln explains the significance of scientists’ first observation of the famous Higgs boson, responsible for imparting mass, interacting with the heaviest particle in the universe.