3
$\begingroup$

If matter and antimatter annihilate each other, why is the pentaquark stable since quarks are matter and the antiquark is antimatter?

$\endgroup$
3
$\begingroup$

It depends on whether or not the system corresponds to a $SU (3) $ singlet representation (a one dimensional irreducible representation). This is the color confinement postulate: (here somewhat sloppily) particles we can observe are in a singlet of $SU (3) $.

You can show by tensorial decomposition that the mesons and the baryons contain a singlet representation of $SU (3)$, the pentaquark should too. I once tried to do the math but did not end the computation.

Now I don't have phenomenological knowledge of the lifetime of the pentaquark and this could be a relevant reason as for why color confinement should not apply in the pentaq case.

| cite | improve this answer | |
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.