The Top Quark, Its Discovery, and Subsequent Research

Resources with Additional Information

'Ever since the existence of the bottom (or b) quark was inferred from the discovery of the Upsilon family of resonances at Fermilab in 1977, particle physicists have been on the lookout for its partner, called top (or t). The long search, which occupied experimenters at laboratories around the world, came to a successful conclusion in February 1995 with the announcement that the top quark had been observed in two experiments at the Tevatron proton-antiproton collider at Fermilab. ...

Courtesy Fermilab

Top is the last of the fundamental constituents of subnuclear matter that theories of the strong, weak, and electromagnetic interactions and a wealth of experimental information had led particle physicists to expect. Theoretically, top's existence was required to make the electroweak theory internally consistent.'¹

'The discovery of the top quark fills an important hole in the Standard Model. ...

Even with the energies available in the Tevatron and with the most sophisticated detectors, the top was hard to find. Tops and bottoms had previously only existed in the early universe. They all decayed long ago into other particles. They decay so quickly (physicists say they have short lifetimes) that, even after a top is made from a proton-antiproton collision, a rare event itself, it exists for such a short time that it cannot be directly observed. Rather, the products of top decay are identified and traced back to the top after extensive computer analysis.'²

Resources with Additional Information

Additional information about the top quark is available in documents and on the Web.

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