In pairticle pheesics, mesons (/ˈmzɒnz/ or /ˈmɛzɒnz/) are hadronic subatomic pairticles componed o ane quark an ane antiquark, bound thegither bi the strang interaction. Acause mesons are componed o sub-pairticles, thay hae a pheesical size, wi a radius roughly ane femtometre, which is aboot ​23 the size o a proton or neutron. Aw mesons are unstable, wi the langest-lived lastin for anly a few hundredths o a microseicont. Charged mesons decay (sometimes through intermediate pairticles) tae furm electrons an neutrinos. Uncharged mesons mey decay tae photons.