You are here:

Physics/Measurement of intrinsic parity


QUESTION: Could you please explain how the intrinsic parity of an elementary particle is measured. For instance, if a new particle is observed in the LHC, how does one determine the intrinsic parity of that particle? What are the observables?

I'm asking because the apparent "discovery" of the Higgs boson indicates it has a positive parity. How was that determined?

ANSWER: They do a pretty good job of explaining how the angles that stuff comes out from the decay of the Higgs boson are what determine its parity in this article:  As to how this is so, you'd need a deeper course in quantum mechanics and particle physics.  The data is too complex to be broken down in a much simpler way than this particular article does it.

---------- FOLLOW-UP ----------

QUESTION: Thanks - that link helps.

From a high level, I would assume that if two particles have the same spin and charge (easier to understand and measure), but one obeys the "left-hand rule" and one obeys the "right-hand rule" in the same magnetic field, they must have different parity. Please correct me if I'm wrong. If not, thanks again.

The electromagnetic force is invariant under a parity transformation, so no, not at all.  It involves the weak interaction, see here:  Hyperphysics is a good resource for further references, as well.


All Answers

Answers by Expert:

Ask Experts


Dr. Stephen O. Nelson


I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.


I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.

©2017 All rights reserved.