Word To Use Today: pentaquark.

Pentaquark...well, that'll be something made of five quarks, won't it.

In 2008 the Review of Physics referred to the 'overwhelming evidence' that pentaquarks - and they are indeed made of groups of five quarks -  don't exist (whatever exist means to a nuclear physicist). 

Now, however, the scientists at CERN are saying that they have some figures that make it look very much as though pentaquarks are real and active and out there.

(The maths used to work this out is called chromodynamics, but although the chromo bit of this word is to do with colour, as you'd expect, what nuclear physicists call colour is nothing to do with, well, colour...obviously.)

Yes, yes, all right, it's true, I have very little idea what I'm talking about, but I do love the words. I mean, it seems that the five quarks of a pentaquark might be bound together with gluons.

Gluons. Isn't that great?

Anyway, the theory is that a pentaquark consists of five quarks, but because one of them is an antiquark it sort of cancels out one of the ordinary quarks and so a pentaquark looks jolly like an ordinary triquark, which consists of three quarks.


Image by Smurrayinchester. the c with the line above it is the antiquark. The c stands for charm, and the u and d for up and down.

The colours of the five quarks probably cancel each other out, too. So, for instance, you might have one red quark, one blue, two green, and one antigreen.

I do love the idea of antigreen.

Anyway, pentaquarks are probably jolly important. You might, for instance, need to use pentaquarks when making a neutron star. 

As one...

...er...

...doesn't.

Ah well, here's a final thought: pentaquarks can probably be made up of any type of quark, which come in six varieties: up, down, top, bottom, charm and strange.

Though it's very difficult to imagine a part of a pentaquark that isn't very very strange indeed.

Word To Use Today: pentaquark. This word was made up by Harry J Lipkin in 1987, though the idea of a pentaquark has been around since 1964 when Murray Gell-Mann first started wondering about quarks.