In terms of importance, quarks are up there with gauge bosons/ exchange particles (Beauties we will go on to discuss later, I promise (One of my favourite particles is an exchange particle, both for serious and silly reasons…)). They are the very building blocks of larger particles which make you and me up.
As discussed previously, Hadrons are composite particles, particles made up of even smaller particles known as Quarks. They were discovered in 1968 at the Stanford Linear Accelerator Centre, MIT, after electrons fired at protons and neutrons bounced back in an unexpected direction (1). Since then , 6 quarks have been discovered and all play a part in making up composite particles. What are these 6 quarks, I hear you ask (Humour me, please)?
As you can probably deduce, there are 6 flavours of quark, flavour meaning type in this instance (You’d need a whole lot of quarks to even begin to know what one tastes like (Though I guess we are always tasting quarks, really)). Quarks come in pairs (Up-Down, Charm-Strange (My apologies for the way they are pictured), Top-Bottom) with Up, Charm and Top possessing a charge of 2/3 e (e stands for elementary charge, find out more here) whilst Down, Strange and Bottom possessing a charge of -1/3 e.
Quarks cannot exist in isolation. Even if you were to bombard something like a hadron with enough energy, the energy would simply become more quarks and anti-quarks. This process is referred to as pair production, something we will look at with greater detail when we consider anti-particles (2). Quarks come together in 1 of 2 ways: 3 quarks/antiquarks (Hadron) or a quark and an antiquark (Meson).
When we think about quarks in the grand scheme of things, we consider Up and Down quarks for the most part as they are the most common ones we find. We also consider their anti-quark equivalents which, again, is something I will touch upon in greater detail when we take a look at anti-particles.
There you have it, quarks. If you fancy exploring the topic a little further, I would recommend giving this tune a listen. I apologise in advance for the chorus, it is quite catchy. If you have any thoughts or questions please feel free to leave them in the comments below.
- The University of Kansas (2013) When were quarks discovered? Available at: http://www.quarked.org/askmarks/answer25.html (Last Accessed: 21st November 2017)
- CGP (2015) A-level Physics Exam Board: OCR A, Elanders Ltd, Newcastle, pg 162