Voorbeelden van quark

• Until a few years ago, it was believed that some experiments showed the existence of "pentaquarks" exotic baryons made of four quarks and one antiquark.

• Baryons, along with mesons, are hadrons, meaning they are particles composed of quarks.

• Mesons are part of the hadron particle family, defined simply as particles composed of quarks.

• The phenomenon of uncertainty takes a quizzical glimpse at quarks and a world in constant flux.

• One simple solution exists: if at least one of the quarks of the standard model is massless, becomes unobservable; i.e. it vanishes from the theory.

• Thus, the sum of the quarks' spin was expected to be equal to the proton's spin.

• Physicists expected that the quarks carry all the proton spin.

• They are baryons containing no up or down quarks.