How were quarks discovered

Particle physics Why the quarks have something to do with the quark

So actually quarks also have something to do with quark. But just as well with every human body, animal, plant - in short with the whole world. Quarks are the smallest building blocks that make up the world, or rather visible matter, as far as we know today.

Because that is the old question of mankind: What is the world made of? For a long time it was thought that atoms were the smallest building blocks. Simply put, atoms are made up of a shell of electrons and a nucleus of neutrons and protons. But what are neutrons and electrons and protons made of? From quarks.

Scientists shot atoms to pieces

There are six different ones and they have very idiosyncratic names like strange quark and charm quark and the top quark that was discovered 25 years ago. Or not discovered, but proven experimentally.

Top quarks do not occur in nature - "nature" in the sense of visible matter. They are generated by high-energy particle collisions. And that was first achieved on March 3, 1995 at the Tevatron - a particle accelerator at the Fermilab research center in the USA.

Incidentally, the mass of the top quark is very large and its lifespan is extremely short. It thus occupies a special position among the elementary particles.

All quarks only existed in theory for a long time until they were proven one after the other. One reason: Quarks are never found in isolation in nature. They are simply always in the atoms, i.e. electrons, protons and neutrons and they are tiny. It was only when scientists started shooting atoms to pieces that they could slowly be detected.

Physical names like from a children's series

But those are strange names too. Beauty quark - so beauty quark? Strange quark - the strange quark? Sounds like something out of a children's series. Why do they have such names? Steffen Turkat from TU Dresden explains why:

That has grown historically. There are six different quarks and they weren't all found at the same time - only in 1969 the up quark, the down quark and the strange quark. That didn't fit in with the theory at the time, that was strange. [...] Then later the charm quark - a charming one because it made everything symmetrical again. And then there were two more: the bottom quark and the top quark.

Steffen Turkat, nuclear physicist at the TU Dresden

It's James Joyce's fault

And why are these things now called "quarks"? Because physicists are firstly well read and secondly have a sense of humor. The Irish author James Joyce was once on the road in Germany and probably heard the sellers praising their "Quark" at the market in Freiburg. He later used this word in a novel.

This novel was obviously known to Murray Gell-Mann - one of the first physicists to work on the theory of quarks. He also liked the word quark very much. When he was allowed to name new particles, he decided on quark. And so the smallest building blocks of visible matter known to us are called after a German dairy dish.