Expanding the Bari family
2007/01/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria
Although all matter is formed by quarkes, in common matter only certain combinations of quarks occur. Two particles containing another combination have now been detected.
The particles formed by three quarkes are called barions, among which are, for example, neutrons and protons. The latter are formed by light quark of type u and d, while in the new sigma-b barions found the quarka type b appears for the first time in the combinations u-u-b and d-d-b. They are the heaviest that have been found, a proton weighs 6 times and are very unstable: they have a life of very small fraction in a second.
This type of unstable particles can occur in interactions between atoms and cosmic rays of the atmosphere or in high-energy collisions in particle accelerators. And, in this case, they have achieved it using the most powerful particle accelerator in the world. This discovery, in addition to confirming quark theory, will help investigate how matter is formed from quarkets and better understand the nuclear forces that unite or separate quarks.
