Hyperon

In particle Physics, a Hyperon is any baryon containing one or more strange quarks, but no charm quarks or bottom quarks. Hyperons are subatomic particles of the class known as baryons. Like all baryons, they are composed of quarks. The term hyperon is generally used for a baryon containing one or more strange quarks as opposed to the proton and neutron, which contains only up and down quarks. The strange quark is unstable, where hyperons decay into lighter baryons with typical lifetimes of approximately 1/10 of a nanosecond. At high energies, these lifetimes are sufficient for a hyperon to travel several meters before decaying, since the hyperon can be moving nearly at the speed of light and thus experience the time- dilation effect of Special Relativity. This long decay distance makes hyperon- beam experiments feasible.

The hyperons are distinct from the nucleons, protons and the neutrons as they contain one or more strange quarks. Hyperons include the lambda zero particle, a triplet of sigma particles, a doublet of xi particles and the omega- minus particle. The discovery of the omega- minus hyperon was suggested by the eightfold Way of classifying hadrons, the more general group of subatomic particles to which hyperons are assigned. Hadrons are composed of quarks and interact with one another via the strong force.

The formation of Hyperons

Hyperon are produced by the strong force in the time it takes for a particle traveling at nearly the speed of light to cross the diameter of a subatomic particle, but their decay is caused by the weak force which is involved in radioactive decay takes millions and millions time longer. Because of their behavior, hyperons along with K- mesons, with which they are often produced- were named strange particles. This behavior has since been ascribed to the weak decays of the specific quarks.

Properties and behavior of Hyperons

Being baryons, all hyperons are femions, i.e. they have half- integer spin and obey Fermi-Dirac statistics. They all interact via the strong nuclear force, making them types of hadron. They are composed of three light quarks, at least one of which is a strange quark, which makes them strange baryons.

Hyperon Research

The first research into hyperon happened in the 1950’s and spurred physicists on the creation of an organized classification of particles. Today research in this area is carried out on data taken at many facilities around the world including CERN, Fermilab, SLAC, JLAB, Brookhaven National Laboratory and KEK.

Questions:

• What is a Hyperon?
• How are hyperons produced?