Remarks and Rigorous Bounds Relating to the Decay ZπγZ \to \pi \gamma and Its Relationship to the Anomaly

Jun 5, 1990
10 pages
Published in:
  • Mod.Phys.Lett.A 5 (1990) 2281-2288
Report number:
  • LA-UR-90-1810

Citations per year

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Abstract: (WSP)
It is rigorously shown that the amplitude for the decay Z → πγ must fall at least as fast as MZ1M_Z^{-1}. Consequently its branching ratio must be smaller than 10−4; with slightly less conservative assumptions, this limit reduces to 5 × 10−6. The anomaly, the triangle graph and the Ward identities are shown to be consistent with both these bounds and the rate for π0 → 2γ.
  • Z0: radiative decay
  • radiative decay: Z0
  • Z0: branching ratio
  • anomaly
  • PCAC model
  • Ward identity
  • numerical calculations
  • Z0 --> pi0 photon