What is the meaning of chiral-odd/chiral-even functions

[joly]

I read about quark distribution functions in the nucleon that are chiral-odd or chiral-even functions (Sivers function, Boer-Mulders function and other distribution function related to nucleon transversity). What is the definition of chirality for functions? Does this mean they are odd or even under the transformation (t,x,y,z) -> (t,-x,-y,z) ?

Thanks!

 

[Simon Bridge]

That's basically it - look up "chiral symmetry" for the physics use. ie. in QM you are thinking of behavior of a state under an operator.
https://en.wikipedia.org/wiki/Chirality_(physics)#Example:_u_and_d_quarks_in_QCD

 

[joly]

Thank you. So in better terms than what I used, it means that when one switches the right handed quarks in a nucleon with the left handed ones, a chiral-odd distribution function switches its sign while a chiral-even one retains its sign. Is that correct?

 

[Simon Bridge]

Off the top of my head, that would be what I'd expect.
I'm thinking you should relate this to your course-notes and text here though... I may not have the same idea of a "distribution function" that your prof has.