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Meaning of h.c. in Lagrangians (& elsewhere?)

  1. Dec 5, 2010 #1
    Meaning of "h.c." in Lagrangians (& elsewhere?)

    I am fairly new to particle physics and am puzzled by an abbreviation I often see in Lagrangians here (though it may not be particular to that application): " + h.c." is tacked on after other terms. What does this denote? Apologies if I've missed something very simple, and thanks for the help either way!
  2. jcsd
  3. Dec 5, 2010 #2


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    Re: Meaning of "h.c." in Lagrangians (& elsewhere?)

    This is not unique to particle physics. All it means is that there are additional terms which are the hermitian conjugate of the terms that have already been written.

  4. Dec 5, 2010 #3
    Re: Meaning of "h.c." in Lagrangians (& elsewhere?)

    What Zz said. The Hamiltonian should be a hermitian operator, but note that if we have any (well-behaved) operator A, then A + Adagger is hermitian. So the notation is both a convenient way of making sure we have a hermitian operator and a convenient shorthand to omit half the terms present.
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