I have a simple question about parity and semantics. (And it's coursework/textbook related, so I assume it goes here.)(adsbygoogle = window.adsbygoogle || []).push({});

When someone says, "Such-and-such particle has parity of +1," does this mean that if we operate on the state representing that particle, we get back that same state times +1? That is, forany particle[itex]p[/itex] (not only the proton, which p sometimes stands for),

[tex]P |p \rangle = \lambda |p \rangle [/tex]

so that, if "the parity of [itex]p[/itex]" is, say, -1, thenwhat we mean in saying thisis that [itex]\lambda = -1[/itex] for the particle [itex]p[/itex], and

[tex]P |p \rangle = - |p \rangle[/tex]?

(Analogously, if we say "the particle [itex]p[/itex] has spin of 1/2", what we really mean is that [itex]S_{z} |p \rangle = m_{s} |p \rangle = \pm \frac{1}{2} |p \rangle[/itex], right?)

It's easy to find resources on how to do the math for this stuff, but finding outhow to speak about itproperly is not as easy. So thanks for any insight!

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# Homework Help: How to talk about parity.

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