Clebsch Gordan coefficients

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In summary, in CG coefficients methodology, there is a convention that the value of the Clebsch-Gordan coefficient, represented by the expression <J1 J2 J1 J-J1|J1 J2 J J>, must be greater than or equal to 0. This convention is used when the values of J1 and J2 are known, such as in the example given where J1=1 and J2=1/2. However, when J=3/2, the maximum value of angular momentum, there is only one CG coefficient and it can be written as <1 1/2 1/2 1|1 1/2 3/2 3/2> = 1
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LagrangeEuler
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In CG coefficients methodology there is convention
[tex]\langle J_1 J_2 J_1 J-J_1|J_1 J_2 J J \rangle \geq 0[/tex]
So if we have ##J_1=1##, ##J_2=1/2##
[tex]\langle 1 \quad 1/2 \quad 1/2 \quad 1|1 \quad 1/2 \quad 3/2 \quad 3/2\rangle \geq 0[/tex]
using this convention. However, because ##J=3/2## is maximal value of angular moment, this is only CG coefficient and we could write
[tex]\langle 1 \quad 1/2 \quad1/2 \quad 1|1 \quad 1/2 \quad 3/2 \quad 3/2\rangle =1[/tex]
Now if we work with ##J_-## operator we will obtain that
[tex]\langle 1 \quad 1/2 \quad -1/2 \quad -1|1 \quad 1/2 \quad -3/2 \quad -3/2\rangle =1[/tex]
Do we have some similar convention for this lowest value of angular momentum?
 
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FAQ: Clebsch Gordan coefficients

What are Clebsch Gordan coefficients?

Clebsch Gordan coefficients are mathematical quantities used in physics, specifically in the field of quantum mechanics, to represent the transformation of angular momentum between two particles.

Why are Clebsch Gordan coefficients important?

Clebsch Gordan coefficients are important because they allow us to predict the outcome of quantum mechanical processes involving the combination of angular momenta of two particles. They also provide a way to describe the properties of composite systems, such as atoms or molecules.

How are Clebsch Gordan coefficients calculated?

Clebsch Gordan coefficients are calculated using the Clebsch Gordan formula, which involves the use of the Wigner 3-j symbols. The calculation is complex and involves understanding the quantum numbers and states of the particles involved.

What are the physical interpretations of Clebsch Gordan coefficients?

The physical interpretations of Clebsch Gordan coefficients include the prediction of the total angular momentum of a composite system, the possible outcomes of quantum mechanical processes involving angular momenta, and the probability of finding a specific angular momentum state in a composite system.

How are Clebsch Gordan coefficients used in physics experiments?

Clebsch Gordan coefficients are used in a variety of physics experiments, including those involving atomic and molecular spectroscopy, nuclear physics, and particle physics. They are also used in theoretical calculations and simulations to predict the behavior of quantum mechanical systems.

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