Table of Baryons

ParticleSymbolMakeupRest mass
MeV/c^2
SpinBS
Lifetime
(seconds>
Decay Modes
Proton
p
uud
938.3
1/2
+1
0
Stable
...
Neutron
n
ddu
939.6
1/2
+1
0
920
Lambda
uds
1115.6
1/2
+1
-1
2.6x10-10
Sigma
uus
1189.4
1/2
+1
-1
0.8x10-10
Sigma
uds
1192.5
1/2
+1
-1
6x10-20
Sigma
dds
1197.3
1/2
+1
-1
1.5x10-10
Delta
uuu
1232
3/2
+1
0
0.6x10-23
Delta
uud
1232
3/2
+1
0
0.6x10-23
Delta
udd
1232
3/2
+1
0
0.6x10-23
Delta
ddd
1232
3/2
+1
0
0.6x10-23
Xi
Cascade
uss
1315
1/2
+1
-2
2.9x10-10
Xi
Cascade
dss
1321
1/2
+1
-2
1.64x10-10
Omega
sss
1672
3/2
+1
-3
0.82x10-10
Lambda
udc
2281
1/2
+1
0
2x10-13
...
To Meson Table

As an example of the notation in the column of decay modes, the sigma + decay mode is
written , which implies there are two common decay modes,

Particles which decay by the strong interaction typically do so on a time scale of about 10-23 seconds, and some of the baryons listed in the table above have lifetimes on the order of 10-10 seconds. The reason for those longer lifetimes is that they are forbidden by some kind of conservation law from decaying by the strong interaction, and must decay by the weak interaction. These decays involve quark transformations which can be represented by Feynman diagrams.There are dozens of other baryons (i.e., combinations of three quarks), but most of them decay by the strong interaction and are so short lived that they don't leave a measurable track in a bubble chamber or other detection device. These baryons have been detected as "resonances" or peaks in the probability for particle interactions.

Baryon diagram

Baryon discussion

Index

Particle concepts

Reference
Serway
Ch. 47

Griffiths
 
HyperPhysics***** Quantum Physics R Nave
Go Back