3
votes
1answer
86 views

Is there a tb meson?

I was wandering around the particle date group page for meson and couldn't find a meson for top-bottom, which from symmetry you would expect. Q1: Is this because it hasn't been found? Q2: There is ...
9
votes
3answers
890 views

What does it mean that the neutral pion is a mixture of quarks?

The quark composition of the neutral pion ($\pi^0$) is $\frac{u\bar{u} - d\bar{d}}{\sqrt{2}}$. What does this actually mean? I think it's bizarre that a particle doesn't have a definite composition. ...