In particle physics, a hadron / hædrɒn / Greek: rooster, hadrós? "strong, thick" is a composite particle made of two or more quarks that are held together with strong force in a manner similar to how the molecules retain the electromagnetic force. Most of the mass of ordinary matter comes from two heros, progenitors of protons and neutrons. The squares are classified into two families: baryons, formed by an odd number of quarks, usually three quarks, prostitutes, and mesons, formed by an even number of quarks, usually a quark and a dumbbell. Prostitutes of protons and neutrons are examples of baryons. The pions are an example of an inn. "Exotic" rats which contain more than three valerate sugars have been discovered in recent years. A quadruped state, an exotic inn called Z4430-, was discovered in 2007 by Belle Collaboration and was confirmed as a response in 2014 by the collaboration of LHCb. In 2015, the LHCb collaboration found two exotic Pentaquark barons, called P + c4380 and P + c4450. There are many exotic candidate shawls and other combinations of simple color quarks that may also be available. It is believed that almost all "free" and anti-chronic that is, isolated and unbound in an atomic nucleus are unstable and eventually decompose into other particles. The only known exception is related to free protons, which are likely to be stable or at least take enormous amounts of time to weaken the order of more than 1034. Free neutrons are unstable and decompose with a half-life of approximately 611 seconds. It is expected that their respective antibodies follow the same pattern but it is difficult to capture prostitutes and study because they disappear immediately in contact with common matter. The "bound" protons and neutrons contained in an atomic nucleus are generally considered stable. Experimentally, the physiology of anron is studied by the collision of protons or nuclei of heavy elements such as lead or gold, prostitutes and the detection of residues in the particles of the particles produced. In the environment, the mesons, like the pony, are produced by collisions of cosmic rays with the atmosphere.