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Fermi theory

  1. May 18, 2015 #1
    Could you explain what's the interpretation of [tex]a[/tex] before [tex]\gamma^{5}[/tex] in this current:

    [tex]J_{\alpha}=\bar{\psi_{e}}\gamma^{\alpha}\left(1-a\gamma^{5}\right)\psi_{\nu_{e}} +\bar{\psi_{\mu}}\gamma^{\alpha}\left(1-a\gamma^{5}\right)\psi_{\nu_{\mu}}[/tex]?

    And will this factor complicate calculations of decay rate of muon very much? I've seen that the standard form of current in the most popular books contains just [tex]1-\gamma^{5}[/tex].
  2. jcsd
  3. May 18, 2015 #2

    Vanadium 50

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    It is the relative strength of the axial current. It's unity for leptons. But where did you get this? It's a poor way to write this, since it's the vector current that changes.
  4. May 18, 2015 #3
    It's a task from my studies. I have to calculate the decay rate for muon starting from hamiltonian with current in this form. I've started and ran into troubles.
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