${{\mathit B}^{0}}$ $\rightarrow$ ${{\mathit a}}{{\mathit a}}$ , ${{\mathit a}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$  Decay Mode Summary INSPIRE   PDGID:
S042.618
Mode (*) Fraction ($\Gamma_i$ / $\Gamma$) Scale Factor/
Conf. Level
P(MeV/c)  
$\Gamma_{549}$ ${{\mathit B}^{0}}$ $\rightarrow$ ${{\mathit a}}{{\mathit a}}$ , ${{\mathit a}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ $<2.3 \times 10^{-10}$ CL= 95%
Category: Lepton Family number ($\mathit LF$) or Lepton number ($\mathit L$) or Baryon number ($\mathit B$) violating modes, or/and $\Delta \mathit B$ = 1 weak neutral current ($\mathit B1$) modes
Note: (B1) Allowed by higher-order electroweak interactions.
The following data is related to the above value: