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# Physics/Measurement of intrinsic parity

Question
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: http://www.quantumdiaries.org/2012/09/20/how-to-tell-a-higgs-from-another-boson/  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.

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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:  http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/parity.html  Hyperphysics is a good resource for further references, as well.

Physics

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#### Dr. Stephen O. Nelson

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