Spin and Direction: A Complex Relationship in Particle Physics

maxverywell
Messages
197
Reaction score
2
How this two are related? I read somewhere that the spin is always parallel to the direction of motion of particle. If the direction of motion changes by some magnetic field (Lorentz force) what happens to tha spin? Will its axis direction change too?
 
Physics news on Phys.org
maxverywell said:
I read somewhere that the spin is always parallel to the direction of motion of particle.
That's true for massless particles, but not for massive particles.
 
Why it's true for massless particles? Is there any explanation to this?
Btw thnx for your answer!
 
There is, but it's very complicated. It's a part of the mathematical theory of massless representations of the Poincaré group. If you're a bit of a masochist, check out section 2.5 in Weinberg's "The quantum theory of fields" (vol. 1).
 

Thread 'Prof Mike Wiest's proposed link between quantum and consciousness'

I am not sure if this belongs in the biology section, but it appears more of a quantum physics question. Mike Wiest, Associate Professor of Neuroscience at Wellesley College in the US. In 2024 he published the results of an experiment on anaesthesia which purported to point to a role of quantum processes in consciousness; here is a popular exposition: https://neurosciencenews.com/quantum-process-consciousness-27624/ As my expertise in neuroscience doesn't reach up to an ant's ear...
View full post »

Thread 'Quantum Entanglement is a Kinematic Fact, not a Dynamical Effect'

Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated... Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/ by @RUTA
View full post »

Thread 'Is It Known For Sure Infinites In QFT Are Caused Using a Continuum?'

I am reading WHAT IS A QUANTUM FIELD THEORY?" A First Introduction for Mathematicians. The author states (2.4 Finite versus Continuous Models) that the use of continuity causes the infinities in QFT: 'Mathematicians are trained to think of physical space as R3. But our continuous model of physical space as R3 is of course an idealization, both at the scale of the very large and at the scale of the very small. This idealization has proved to be very powerful, but in the case of Quantum...
View full post »

Similar threads

A Coleman: "Spin is a concept that applies only to particles with mass"
Replies
11
Views
1K
I Need Help on Particle Spin
Replies
3
Views
159
I Question about Stern-Gerlach experiment
Replies
12
Views
3K
I Direction of motion of particles with total spin under magnetic field
Replies
1
Views
2K
B Quantum teleportation of usable information
Replies
19
Views
2K
I Precession of spin in a magnetic field
Replies
10
Views
4K
I The Extended Wigner's Friend Scenarios
Replies
42
Views
2K
B How to show that particle spin includes angular momentum?
Replies
14
Views
2K
A Relationship between Larmor precession and energy eigenstates
Replies
15
Views
3K
I Trying to understand why electrons fill orbitals the way they do
Replies
10
Views
2K

Hot Threads

Recent Insights

Back
Top