Table of Baryons

Particle

Symbol

Makeup

Rest mass
MeV/c2

Spin

B

S

Lifetime
(seconds>

Decay Modes

Proton

p

uud

938.3

1/2

+1

0

Stable

...

Neutron

n

ddu

939.6

1/2

+1

0

920

pe-νe

Lambda

Λ0

uds

1115.6

1/2

+1

-1

2.6
x10-10

pπ-, nπ0

Sigma

Σ+

uus

1189.4

1/2

+1

-1

0.8
x10-10

pπ0, nπ+

Sigma

Σ0

uds

1192.5

1/2

+1

-1

6x10-20

Λ0γ

Sigma

Σ-

dds

1197.3

1/2

+1

-1

1.5
x10-10

nπ-

Delta

Δ++

uuu

1232

3/2

+1

0

0.6
x10-23

pπ+

Delta

Δ+

uud

1232

3/2

+1

0

0.6
x10-23

pπ0

Delta

Δ0

udd

1232

3/2

+1

0

0.6
x10-23

nπ0

Delta

Δ-

ddd

1232

3/2

+1

0

0.6
x10-23

nπ-

Xi
Cascade

Ξ0

uss

1315

1/2

+1

-2

2.9
x10-10

Λ0π0

Xi
Cascade

Ξ-

dss

1321

1/2

+1

-2

1.64
x10-10

Λ0π-

Omega

Ω-

sss

1672

3/2

+1

-3

0.82
x10-10

Ξ0π-,
Λ0K-

Lambda

Λ+c

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
pπ0, nπ+

which implies there are two common decay modes,
Σ+ → p + π0
and    Σ+ → n +
π+

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

What
is a pentaquark?

Index

Particle
concepts

Reference
Serway
Ch.
47

Griffiths

Particle
Data Group

HyperPhysics*****
Quantum Physics

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