What Is the Expectation of Angular Momentum Components for a Spin 5 Particle?

In summary, the conversation discusses the notation and operators used in quantum mechanics. The generalized angular momentum operator is represented as \hat{J} and is associated with the magnitude and projection of angular momentum. The spin operator is represented as \hat{S} and is associated with the magnitude and projection of spin. The question being discussed is asking for the expectation of the three components of angular momentum for a spin 5 particle. It is clarified that in this case, j=s=5. The magnitude of the spin is typically seen as the eigenvalue of S2.
  • #1
doublemint
141
0
Hello All,

Right now, I am trying to complete my QM assignment, but I am getting confused about the notation.

So, the generalized angular momentum operator is represented as [itex]\hat{J}[/itex] and -j is the quantum # associated with the magnitude and [itex]m_{j}[/itex] is the quantum # associated with the projection of the angular momentum projection.
Then given j=2, [itex]m_{j}[/itex]=-2,-1,0,1,2
So now onto spin. The spin operator is [itex]\hat{S}[/itex] and similar s is the magnitude of the spin and [itex]m_{s}[/itex] is the projections. Then given s=1/2, [itex]m_{s}[/itex]=1/2,-1/2
So far so good right?
Now what is confusing to me is this: the question is asking for the expectation of the three components of angular momentum of a spin 5 particle. Does it mean s=5 or j=5?

Another question is what does it mean by "the quantum number associated with the magnitude of the spin for a particle"? Are they asking for s?

Thanks
DoubleMint
 
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  • #2
I think they discard the orbital angular momentum, so that j=s=5. The magnitude is usually seen as the eigenvalue of S2.
 

FAQ: What Is the Expectation of Angular Momentum Components for a Spin 5 Particle?

What is spin in quantum mechanics?

Spin refers to an intrinsic property of a quantum particle that determines its angular momentum. It is represented by the quantum number, s, and is measured in units of ħ/2.

What is the difference between orbital angular momentum and spin?

Orbital angular momentum refers to the angular momentum associated with the motion of a particle around an axis. Spin, on the other hand, is an intrinsic property of the particle that does not require motion. It is a form of angular momentum that is associated with the particle's spin axis.

How is angular momentum measured in quantum mechanics?

In quantum mechanics, angular momentum is measured using the operators L and S for orbital and spin angular momentum, respectively. The eigenvalues of these operators represent the possible values of the angular momentum for a given particle.

What is the spin-statistics theorem?

The spin-statistics theorem states that particles with integer spin (0, 1, 2, etc.) are bosons and follow Bose-Einstein statistics, while particles with half-integer spin (1/2, 3/2, 5/2, etc.) are fermions and follow Fermi-Dirac statistics. This theorem is a fundamental principle in quantum mechanics and explains the behavior of particles at a microscopic level.

How does spin affect the behavior of particles?

Spin plays a crucial role in determining the behavior of particles, such as their magnetic properties and interaction with external fields. It also affects the energy levels of atoms and the way particles combine to form larger structures. Spin is an important concept in understanding the quantum world and has many practical applications in fields such as technology and medicine.

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