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Name |
Breit-Wigner Formula |
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Equation |
σ
=
π
ƛ
2
(
2
j
+
1
)
(
2
s
1
+
1
)
(
2
s
2
+
1
)
Γ
2
(
E
0
-
E
)
2
+
Γ
2
/
4
|
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Definition of terms |
σ = cross section,
ƛ
= λ/2π
, where λ/2π = wavelength, j = spin of resonant state, s1 = spin of incident state, s2 = spin of target state, Γ = full width at half height of the resonance, E0 = energy at which cross section is a maximum, E = energy |
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Comments |
The Breit-Wigner formula describes the cross section for the formation of a
particle resonance, intermediate between two other particle states. |
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References
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An Introduction to Elementary Particles , W S C Williams, Academic Press, 1971 |
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