Michel decay

• Neutrino spectrum

  • NLO comparison with [2112.12395]

• Validation of FKS$^2$

  • Validation of FKS$^2$ [1909.10244]

• Demo observable

  • A demo observable for [1909.10244]

• Precision extraction of $f$ and $g$

  • Limit on the ALP branching ratio

  • Best theory prediction for $f$ and $g$