Spin of Particle and Antiparticle: Same or Different?

  • Context: Graduate 
  • Thread starter Thread starter stjimmee
  • Start date Start date
  • Tags Tags
    Antiparticles Spin
Click For Summary
SUMMARY

The discussion confirms that a particle and its antiparticle always possess the same spin due to the commutation of the charge conjugation operator with spin operators. This equality is essential for maintaining Lorentz invariance in the presence of conserved charges. While the general property of spin remains constant, the orientation of the spin can vary independently for each particle. Thus, altering the spin of one does not affect the other.

PREREQUISITES
  • Understanding of quantum mechanics principles, particularly spin and quantum numbers.
  • Familiarity with the charge conjugation operator and its role in particle physics.
  • Knowledge of Lorentz invariance and its significance in theoretical physics.
  • Basic concepts of particle-antiparticle relationships in quantum field theory.
NEXT STEPS
  • Research the implications of charge conjugation in quantum mechanics.
  • Study Lorentz invariance and its applications in particle physics.
  • Explore the concept of spin in quantum mechanics, including its mathematical representation.
  • Investigate the differences between particles and antiparticles in quantum field theory.
USEFUL FOR

Students of physics, particularly those interested in quantum mechanics and particle physics, as well as educators seeking to clarify concepts related to spin and particle-antiparticle relationships.

stjimmee
Messages
1
Reaction score
0
So a simple question, really: Given a particle, will its antiparticle always have the same spin or not? And if not, in which cases will the spin be different?
Thanks in advance.
 
Physics news on Phys.org
Yes, the charge conjugation operator commutes with the spin operators, so the antiparticle always has the same spin as the particle.
 
fzero said:
Yes, the charge conjugation operator commutes with the spin operators, so the antiparticle always has the same spin as the particle.

This is not the real reason why the spins are the same. The spin, or any other quantum numbers of the antiparticle has to be the same with that of the particle, in order for them to be able to establish Lorentz invariance in the presence of conserved charges.
 
Clarification

I'm not really that far in physics (more of an applied guy--and a high school junior), so maybe this question is obvious. Does that mean that if I were to change the spin of one particle, the other would change as well?
 
No. "The spin" in the first 3 posts refers to the general property of the particle, similar to "the electric charge" or "the mass". You cannot change those (at least not in current physics).

The actual orientation of this spin can change, and it can change for each particle individually. There is no single "other particle".
 

Similar threads

Undergrad Violation of spin conservation in pion annihilation
  • · Replies 4 ·
Replies
4
Views
3K
Graduate The Symmetry of Antiparticle Isospin Doublets in Particle Physics
  • · Replies 3 ·
Replies
3
Views
3K
Undergrad Why do all fermions have the same spin 1/2?
  • · Replies 7 ·
Replies
7
Views
4K
Undergrad Majorana Neutrinos: Evidence of Particle vs. Antiparticle?
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Gluon creation and annihilation operators
  • · Replies 4 ·
Replies
4
Views
2K
Graduate Relation between chirality and spin
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Can Antiparticles Collide with Each Other and Create Energy?
  • · Replies 2 ·
Replies
2
Views
2K
Graduate Relation between nuclear shape and it spin number
  • · Replies 8 ·
Replies
8
Views
3K
High School Do charged particles always have spin?
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Antiparticles and Einstein's energy-momentum relation
  • · Replies 21 ·
Replies
21
Views
3K