Discovered in 1947, the Lambda particle was predicted to have a life of only 10-23 seconds.  Experimentally, it was found to live for 10-10 seconds.  Physicists described this property as "strangeness", and this ultimately led to the discovery of the strange quark.  After this, the charm and bottom lambdas were discovered.  Though predicted by the Standard Model, it is unlikely that the top lambda will be found due to the instability of the top quark. 

Baryons - Lambda Particles

1st Generation 2nd Generation 3rd Generation
"Up"
Type Quarks
Up Quark
Mass:   1.87-2.15 MeV
Charge:
2/3
Spin:    
1/2
ID:            u, u
Charm Quark
Mass:   1.18-1.34 GeV
Charge:
2/3
Spin:    
1/2
ID:            c, c
Top Quark
Mass:  172.6-173.6 GeV
Charge:
2/3
Spin:    
1/2
ID:            t, t
"Down" Type Quarks
Down Quark
Mass:    4.63-4.95 MeV
Charge:
-1/3
Spin:    
1/2
ID:            d, d
Strange Quark
Mass:    90-100 MeV
Charge:
-1/3
Spin:    
1/2
ID:            s, s
Bottom Quark
Mass:    4.2 or 4.68 GeV
Charge:
-1/3
Spin:    
1/2
ID:            b, b
Quark Summary                   (compiled from a number of different sources)
Particle Type
Click name for more:
Quark Composition Rest Mass
in MeV
Proton uud 938.3
Neutron ddu 939.6
Lambda
Charmed Lambda
Bottom Lambda
Top Lambda
uds
udc
udb
udt
1,115.6
2,281.0
5,620.2
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Sigma
Delta uuu, uud, udd, ddd 1232.0
Xi
Omega
Physics

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Composite Particles
WILLIAM & DEBORAH HILLYARD
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