In pairticle pheesics, a hadron i// (Greek: ἁδρός, hadrós, "stout, thick") is a composite pairticle made o quarks held thegither bi the strang force (in a seemilar way as atoms an molecules are held thegither bi the electromagnetic force).
Hadrons are categorized intae twa faimilies: baryons (such as protons an neutrons, made o three quarks) an mesons (such as pions, made o ane quark an ane antiquark). Ither types o hadron mey exist, such as tetraquarks (or, mair generally, exotic mesons) an pentaquarks (exotic baryons), but na current evidence conclusively suggests thair existence.
O the hadrons, protons an neutrons boond tae atomic nuclei are stable, whauras ithers are unstable unner ordinary condeetions; free neutrons decay in 15 minutes. Experimentally, hadron pheesics is studied bi collidin protons or nuclei o hivy elements such as leid, an detectin the debris in the produced pairticle showers.