Invariant differential production cross sections for neutral pions and $\eta$ mesons in pp collision at
$\sqrt{s} = 7$ TeV as function of $\pt$ [56] together with fits using Eq.2 (left panel). Ratios of the measured $\pi^0$ and $\eta$ spectra to the fits (right panel). In both panels the error bars depict the combined statistical and systematic uncertainties of the neutral meson data.
\begin{align*} &(2)& E \frac{{\rm d}^3\sigma}{{\rm d}p^3} = \frac{\sigma_{\rm pp}}{2\pi}\frac{{\rm d}N}{{\rm d}y}\frac{(n-1)(n-2)}{nT(nT+m(n-2))} (1+(m_{\rm t}-m)/(nT))^{-n} \end{align*}