{tag=Particle discovered with cosmic rays}
{wiki}

One <strange quark> bound with one <up quark> or a <down quark>. 6 combinations exist, 4 if we consider antiparticles the same as particles.


Kaon

{tag=Particle discovered with cosmic rays}
{title2=1936}
{wiki}


Muon

{tag=Particle discovered with cosmic rays}
{title2=1947}
{wiki}

Conceptually the simplest <mesons>. All of them have neutral <color charge>:
* charged: down + anti-up or up + anti-down, therefore with net electrical charge $\pm1$ <electron charge>
* neutral: down + anti-down or up + anti-up, therefore with net electrical charge 0


Pion

{tag=Particle discovered with cosmic rays}
{title2=1932}
{wiki}


Ciro Santilli @cirosantilli 34

 Tagged: Particle discovered with cosmic rays