Why in news
Physicists discovered the top quark in 1995 at a particle accelerator in the US called the Tevatron, measuring its mass to be 151-197 GeV/c2 (a unit of mass used for subatomic particles)
Other experiments and research groups yielded more precise values over time.
On June 27, physicists at the Large Hadron Collider (LHC) in Europe reported the most precise figure yet: 172.52 GeV/c2.
Top quark
The top quark is the universe’s heaviest elementary particle.
It is 10-times heavier than a water molecule, about three-times as much as a copper atom, and 95% as much as a full caffeine molecule.
As a result, the top quark is so unstable that it could break up into lighter, more stable particles in less than 10−25 seconds.
Its high mass implies that of all elementary particles, it interacts most strongly with the Higgs boson particle
Because top quarks are very massive, large amounts of energy are needed to create one.
The only way to achieve such high energies is through high-energy collisions.
These occur naturally in the Earth's upper atmosphere as cosmic rays collide with particles in the air, or can be created in a particle accelerator.
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