# What are Quarks made of and will they ever decay to this? [duplicate]

What is it that quarks are actually made of? Will they decay into this substance?

As the up and down quarks are the lightest type of quark do they not decay?
I was thinking that if this could happen, there must be lighter quarks?

In response to the comment:

I know that they don't exist on their own but a quark must surely decay at some point into what makes them up?

So I wanted to know: if they decay what do they decay into, and if they do not what are quarks made of?

• Possible duplicates: physics.stackexchange.com/q/16048/2451 and links therein. – Qmechanic Nov 20 '14 at 19:29
• I disagree with this being a duplicate. Seems to me that OP is asking about what quarks decay into, rather than what they're made of. – Kyle Kanos Nov 20 '14 at 20:48
• You might be interested in looking into the preon model, but note that it's not supported by evidence. – HDE 226868 Nov 20 '14 at 22:13

The $u$ & $d$ quarks decay into $d$ & $u$ quarks and bosons (e.g., W bosons)--this is effectively what happens to the hadrons in weak interactions. This (incomplete) chart shows, for instance, $$u\to d+W^+\\ d\to u+W^-$$ There isn't anything sub-quark, as far as the standard model goes.