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STRANGE MESONS
($\mathit S$ = $\pm1$, $\mathit C$ = $\mathit B$ = 0)
${{\mathit K}^{+}}$ = ${\mathit {\mathit u}}$ ${\mathit {\overline{\mathit s}}}$, ${{\mathit K}^{0}}$ = ${\mathit {\mathit d}}$ ${\mathit {\overline{\mathit s}}}$, ${{\overline{\mathit K}}^{0}}$ = ${\mathit {\overline{\mathit d}}}$ ${\mathit {\mathit s}}$, ${{\mathit K}^{-}}$ = ${\mathit {\overline{\mathit u}}}$ ${\mathit {\mathit s}}$, similarly for ${{\mathit K}^{*}}$'s

INSPIRE search

${{\boldsymbol K}_L^0}$

$I(J^P)$ = $1/2(0^{-})$

See related reviews:

$\mathit V_{{\mathit {\mathit u}}{\mathit {\mathit d}}}$, $\mathit V_{{\mathit {\mathit u}}{\mathit {\mathit s}}}$ the Cabibbo Angle, and CKM Unitarity
$\mathit CP$ Violation in ${{\mathit K}_L^0}$ Decays
$\Delta \mathit S$ = $\Delta \mathit Q$ in ${{\mathit K}^{0}}$ Decays

${\mathit m}_{{{\mathit K}_L^0} }–{\mathit m}_{{{\mathit K}_S^0} }$

$(52.93 \pm0.09) \times 10^{8}$ $\hbar{}$ s${}^{-1}$ (S = 1.3)

${{\mathit K}_L^0}$ MEAN LIFE

$(5.116 \pm0.021) \times 10^{-8}$ s (S = 1.1)

▸	ENERGY DEPENDENCE OF ${{\boldsymbol K}_L^0}$ DALITZ PLOT

▸	${{\boldsymbol K}_L^0}$ FORM FACTORS

▸	$\boldsymbol CP$-VIOLATION PARAMETERS IN ${{\boldsymbol K}_L^0}$ DECAYS

▸	PARAMETERS for ${{\boldsymbol K}_L^0}$ $\rightarrow$ ${{\boldsymbol \pi}^{+}}{{\boldsymbol \pi}^{-}}{{\boldsymbol \gamma}}$ DECAY

$\boldsymbol T$ VIOLATION TESTS IN ${{\boldsymbol K}_L^0}$ DECAYS

Im($\xi $) in ${{\mathit K}_{{\mu3}}^{0}}$ DECAY (from transverse ${{\mathit \mu}}$ pol.)

$-0.007 \pm0.026$

▸	$\boldsymbol CPT$-INVARIANCE TESTS IN ${{\boldsymbol K}_L^0}$ DECAYS

▸

$\boldsymbol x$ = A( ${{\overline{\boldsymbol K}}^{0}}$ $\rightarrow$ ${{\boldsymbol \pi}^{-}}{{\boldsymbol \ell}^{+}}{{\boldsymbol \nu}}$ )/A( ${{\boldsymbol K}^{0}}$ $\rightarrow$ ${{\boldsymbol \pi}^{-}}{{\boldsymbol \ell}^{+}}{{\boldsymbol \nu}}$ ) = A($\Delta \boldsymbol S=−\Delta \boldsymbol Q)/A(\Delta \boldsymbol S=\Delta \boldsymbol Q$)

${{\boldsymbol K}_L^0}$ Decay Modes ▸ Expand all decays

▸	Semileptonic modes

▸	Hadronic modes, including Charge conjugation${\times }$Parity Violating ($\boldsymbol CPV$) modes

▸	Semileptonic modes with photons

▸	Hadronic modes with photons or ${{\boldsymbol \ell}}{{\overline{\boldsymbol \ell}}}$ pairs

▸	Other modes with photons or ${{\boldsymbol \ell}}{{\overline{\boldsymbol \ell}}}$ pairs

▸	Charge conjugation ${\times }$ Parity ($\boldsymbol CP$) or Lepton Family number ($\boldsymbol LF$) violating modes, or $\Delta \boldsymbol S$ = 1 weak neutral current ($\boldsymbol S1$) modes

▸	Lorentz invariance violating modes

FOOTNOTES

Constrained Fit information