07/24/2015

In a Mountain of Data, Signs of a New Class of Particles

6:19 minutes

Illustration of the possible layout of the quarks in a pentaquark particle, such as those discovered at LHCb. The five quarks might be tightly bonded. They might also be assembled into a meson (one quark and one antiquark) and a baryon (three quarks), weakly bonded together. Image by Daniel Dominguez / © 2015 CERN
Illustration of the possible layout of the quarks in a pentaquark particle, such as those discovered at LHCb. The five quarks might be tightly bonded. They might also be assembled into a meson (one quark and one antiquark) and a baryon (three quarks), weakly bonded together. Image by Daniel Dominguez / © 2015 CERN

“Three quarks for Muster Mark!” says James Joyce’s Finnegans Wake. Researchers at CERN, however, have found that a more relevant number may be five. Sheldon Stone and colleagues working on CERN’s LHCb experiment report that they’ve found evidence of a so-called pentaquark particlea particle composed of two up quarks, one down quark, one charm quark, and one anticharm. Pentaquarks were seen as a possibility in theories dating back to the 1960s, but have not been observed in nature until now. While researchers still aren’t sure exactly how the particle may be bound together, the finding may point in the direction of interesting physics at the subatomic level.

Segment Guests

Sheldon Stone

Sheldon Stone is a distinguished professor of physics at Syracuse University in New York.

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About Charles Bergquist

As Science Friday’s director, Charles Bergquist channels the chaos of a live production studio into something sounding like a radio program. Favorite topics include planetary sciences, chemistry, materials, and shiny things with blinking lights.