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CHARGE CONJUGATION ($\mathit C$) INVARIANCE

$\Gamma\mathrm {( {{\mathit \pi}^{0}} \rightarrow 3 {{\mathit \gamma}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<3.1\times 10^{-8}$ CL=90.0%

$\Gamma\mathrm {(( {{\mathit e}^{+}} {{\mathit e}^{-}} )_{\mathit J = 0} \rightarrow 3 {{\mathit \gamma}} )}/\Gamma\mathrm {(( {{\mathit e}^{+}} {{\mathit e}^{-}} )_{\mathit J = 0} \rightarrow 2 {{\mathit \gamma}} )}$

$<1 \times 10^{-5}$ CL=90.0%

$\Gamma\mathrm {(( {{\mathit e}^{+}} {{\mathit e}^{-}} )_{\mathit J = 1} \rightarrow 4 {{\mathit \gamma}} )}/\Gamma\mathrm {(( {{\mathit e}^{+}} {{\mathit e}^{-}} )_{\mathit J = 1} \rightarrow 3 {{\mathit \gamma}} )}$

$<1 \times 10^{-5}$ CL=90.0%

${{\mathit \eta}}$ $\mathit C$-nonconserving decay parameters

${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ left-right asymmetry

$0.0009$ ${}^{+0.0011}_{-0.0012}$

${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ sextant asymmetry

$0.0012$ ${}^{+0.0010}_{-0.0011}$

${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ quadrant asymmetry

($-9$ $\pm9$) $ \times 10^{-4}$

${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$ left-right asymmetry

$0.009$ $\pm0.004$

${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$ parameter $\beta $ (${\mathit D}{\mathrm -wave}$)

$-0.02$ $\pm0.07$ (S = 1.3)

$\Gamma\mathrm {( {{\mathit \eta}} \rightarrow 3 {{\mathit \pi}^{0}} {{\mathit \gamma}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<6\times 10^{-5}$ CL=90.0%

$\Gamma\mathrm {( {{\mathit \eta}} \rightarrow {{\mathit \pi}^{0}} {{\mathit \gamma}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<9\times 10^{-5}$ CL=90.0%

$\Gamma\mathrm {( {{\mathit \eta}} \rightarrow 2 {{\mathit \pi}^{0}} {{\mathit \gamma}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<5\times 10^{-4}$ CL=90.0%

$\Gamma\mathrm {( {{\mathit \eta}} \rightarrow 3 {{\mathit \gamma}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<1.6\times 10^{-5}$ CL=90.0%

$\Gamma\mathrm {( {{\mathit \eta}} \rightarrow {{\mathit \pi}^{0}} {{\mathit \mu}^{+}} {{\mathit \mu}^{-}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<5\times 10^{-6}$ CL=90.0%

$\Gamma\mathrm {( {{\mathit \eta}} \rightarrow {{\mathit \pi}^{0}} {{\mathit e}^{+}} {{\mathit e}^{-}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<8\times 10^{-6}$ CL=90.0%

$\Gamma\mathrm {( {{\mathit \omega}{(782)}} \rightarrow 2 {{\mathit \pi}^{0}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<2.2\times 10^{-4}$ CL=90.0%

$\Gamma\mathrm {( {{\mathit \omega}{(782)}} \rightarrow 3 {{\mathit \pi}^{0}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<2.3\times 10^{-4}$ CL=90.0%

$\Gamma\mathrm {( {{\mathit \omega}{(782)}} \rightarrow {{\mathit \eta}} {{\mathit \pi}^{0}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<2.1\times 10^{-4}$ CL=90.0%

${{\mathit \eta}^{\,'}{(958)}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$ decay asymmetry parameter

$-0.03$ $\pm0.04$

$\Gamma\mathrm {( {{\mathit \eta}^{\,'}{(958)}} \rightarrow 3 {{\mathit \gamma}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<1.0\times 10^{-4}$ CL=90.0%

$\Gamma\mathrm {( {{\mathit \eta}^{\,'}{(958)}} \rightarrow {{\mathit \mu}^{+}} {{\mathit \mu}^{-}} {{\mathit \pi}^{0}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<6.0\times 10^{-5}$ CL=90.0%

$\Gamma\mathrm {( {{\mathit \eta}^{\,'}{(958)}} \rightarrow {{\mathit \mu}^{+}} {{\mathit \mu}^{-}} {{\mathit \eta}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<1.5\times 10^{-5}$ CL=90.0%

$\Gamma\mathrm {( {{\mathit \eta}^{\,'}{(958)}} \rightarrow {{\mathit \pi}^{0}} {{\mathit \rho}^{0}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<4\%$ CL=90.0%

$\Gamma\mathrm {( {{\mathit \eta}^{\,'}{(958)}} \rightarrow {{\mathit \eta}} {{\mathit e}^{+}} {{\mathit e}^{-}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<2.4\times 10^{-3}$ CL=90.0%

$\Gamma\mathrm {( {{\mathit \eta}^{\,'}{(958)}} \rightarrow {{\mathit \pi}^{0}} {{\mathit e}^{+}} {{\mathit e}^{-}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<1.4\times 10^{-3}$ CL=90.0%

$\Gamma\mathrm {( {{\mathit J / \psi}{(1S)}} \rightarrow {{\mathit \gamma}} {{\mathit \phi}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<1.4\times 10^{-6}$ CL=90.0%

$\Gamma\mathrm {( {{\mathit J / \psi}{(1S)}} \rightarrow {{\mathit \gamma}} {{\mathit \gamma}} )}$ $/$ $\Gamma\mathrm {(total)}$

$<2.7\times 10^{-7}$ CL=90.0%

[1]	Forbidden by angular momentum conservation.

[2]	$\mathit C$ parity forbids this to occur as a single-photon process.

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