# Is Λ the ∑ particle? or is Λ the Δ particle? notation clarification

1. ### rwooduk

486
ive noticed some problems have the quark composition of Λ as uds, but in the Baryon Octuplet that is the same composition as ∑. I always thought Λ was another way of writing Δ, so the quark composition would be ddu, am I wrong?

2. ### kjhskj75

16
Yes, you are wrong, Λ (Lambda) and Δ (Delta) are different greek letters and different particles.

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3. ### Vanadium 50

18,223
Staff Emeritus
Yes, you are wrong. The Lambda and the Delta are different particles with different symbols. The bottom line of the triangle is significant. The neutral Sigma and Lambda have the same quark content, but are still different particles, just as C2H6O can be either ethanol or dimethyl ether.

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4. ### rwooduk

486
Thanks for clearing that up, much appreciated.

5. ### clem

1,276
The u and d quarks in the Lambda are in a spin zero state.
The u and d quarks in the Sigma0 are in a spin one state.

6. ### ChrisVer

2,369
They are excitations of the same quark content bound state...Just as Δ+ is an excitation of the proton...