= Solution
\b[TODO: the numerical resonance-area reading is unavailable from the retained source.] Page 6 retains the upper data panels but loses the lower part of the scanned data image, including the numerical horizontal <energy> calibration. A vertical <cross section> scale and an apparent peak cannot supply $\int\sigma\,dE$ without that calibration. The decoded image contains 2,834,898 of 4,437,216 required RGB bytes; the archived bundle has the same truncation. No horizontal scale or natural <decay width> is inferred from the display width.
The recoverable numerical conversion is nevertheless definite. With $M\simeq3.1\,\mathrm{GeV}$, $B_{ee}=0.060$, $\epsilon=0.50$, and $1\,\mathrm{GeV}^{-2}=389400\,\mathrm{nb}$, <3/b> gives
$$
\Gamma[\mathrm{keV}]=0.2315\,\mathcal I_{ee}^{\rm obs}[\mathrm{nb\,MeV}].
$$
This coefficient assumes the plotted exclusive electronic sample has not already been corrected for acceptance. A restored area, with continuum subtraction and acceptance convention checked, would complete the estimate. A tabulated modern <J psi meson> width would be external information rather than a reading of these data.
The narrow <scattering resonance> indicates suppressed <strong interaction> decay. In the <quark model>, $c\bar c$ is below the open-<charm quark> $D\bar D$ threshold, so its constituents cannot simply emerge in separate charmed <mesons>. The <OZI rule> suppresses annihilation into light <hadrons>; for a $1^{--}$ color-singlet state the leading purely gluonic channel needs three <gluons>. The observed leptonic channels remain competitive. Its mass and $I=0$ fit <charmonium>; the small width alone would not uniquely identify the new <quark flavour> without the wider spectrum and threshold evidence.
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