Physics 357 : Decuplets

Baryon Multiplets       (F&H Section 15.5)

There are two L=0 ground state baryon multiplets. Considering only baryons containing up, down, and strange quarks they are:

A JP = 1/2- octet: (name, quarks, mass (MeV)), in which one quark has spin aligned opposite to the other two quarks.

n

duu

939.57
p

duu

938.27
S-

dds

1197.4
S0/L

dus

1192.6/ 1115.7
S+

uus

1189.4
X-

dss

1321.3
X0

uss

1314.9

Each member of the octet has simultaneous flavour-spin symmetry, e.g.

Similarly, if all the quark spins are aligned, we have the

JP = 3/2- decuplet

D-

ddd

?
D0

ddu

1234
D+

duu

~1232
D++

uuu

1231
S-*

dds

1387.2
S0*

dus

1383.7
S+*

uus

1382.8
X-*

dss

1535.0
X0*

uss

1531.8
W-

sss

1672.4

The Omega- was predicted by the quark model.

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Copyright 1998 David Bailey, University of Toronto