# Half-spin baryons with identicle quarks?

1. Jul 30, 2012

### bsaucer

Do any 1/2 spin baryons exist that are made of three identical (flavored) quarks? I know the Δ-, Δ++ and Ω- have 3/2 spin. If the 1/2 spin versions of these particles can't exist, then why not?

2. Jul 30, 2012

### Jason Rong

The color wave function is totally antisymmetric, the flavor is totally symmetric, so that the spin has to be totally symmetric.

3. Jul 30, 2012

### fzero

Spin of a composite particle is best identified with the total angular momentum J = L + S, where L and S are the "orbital" and spin angular momentum of the constituents. There are indeed spin 1/2 versions of the $\Delta$ particles, which are in different orbital angular momentum states compared to the lightest $\Delta$. A list can be found here: http://pdglive.lbl.gov/listing.brl?fsizein=1&exp=Y&group=BXXX020 [Broken]. The known $\Omega$ states are listed at http://pdglive.lbl.gov/listing.brl?fsizein=1&exp=Y&group=BXXX035 [Broken]. It doesn't appear that their angular momentum has been well measured. Presumably they are too short-lived, or their decays too dirty to make this easy, but I am no experimentalist.

Last edited by a moderator: May 6, 2017