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$\pi ^{0}$ and $\eta$ meson production in proton-proton collisions at $\sqrt{s}=8$ TeV

The collaboration
Eur.Phys.J. C78 (2018) 263, 2018

Abstract (data abstract)
CERN-LHC. An invariant differential cross section measurement of inclusive $\pi^{0}$ and $\eta$ meson production at mid-rapidity in pp collisions at $\sqrt{s}=8$~TeV was carried out by the ALICE experiment at the LHC. The spectra of $\pi^{0}$ and $\eta$ mesons are measured in transverse momentum ranges of $0.3<p_{\rm T}<35$~GeV/$c$ and $0.5<p_{\rm T}<35$~GeV/$c$, respectively. Next-to-leading order perturbative QCD calculations using fragmentation functions DSS14 for the $\pi^{0}$ and AESSS for the $\eta$ overestimate the cross sections of both neutral mesons, although such calculations agree with the measured $\eta/\pi^{0}$ ratio within uncertainties. The results are also compared with PYTHIA~8.2 predictions for which the Monash~2013 tune yields the best agreement with the measured neutral meson spectra. The measurements confirm a universal behavior of the $\eta/\pi^{0}$ ratio seen for NA27, PHENIX and ALICE data for pp collisions from $\sqrt{s}=27.5$~GeV to $\sqrt{s}=8$~TeV within experimental uncertainties. A relation between the $\pi^{0}$ and $\eta$ production cross sections for pp collisions at $\sqrt{s}=8$~TeV is given by \mT scaling for $p_{\rm T}>3.5$~GeV/$c$. However, a deviation from this empirical scaling rule is observed for transverse momenta below $p_{\rm T}<3.5$~GeV/$c$ in the $\eta/\pi^{0}$ ratio with a significance of $6.2\sigma$.

• #### Table 1

Data from Fig. 7

10.17182/hepdata.79044.v2/t1

Invariant differential cross section of $\pi^0$ produced in inelastic pp collisions at center of mass energy 8 TeV, the uncertainty...

• #### Table 2

Data from Fig. 7

10.17182/hepdata.79044.v2/t2

Invariant differential cross section of $\eta$ produced in inelastic pp collisions at center of mass energy 8 TeV, the uncertainty...

• #### Table 3

Data from Table 6

10.17182/hepdata.79044.v2/t3

Integrated yields of $\pi^{0}$ mesons produced in inelastic pp collisions at center of mass energies of 2.76 and 8 TeV....

• #### Table 4

Data from Table 6

10.17182/hepdata.79044.v2/t4

Integrated yields of $\eta$ mesons produced in inelastic pp collisions at center of mass energies of 2.76 and 8 TeV....

• #### Table 5

Data from Table 6

10.17182/hepdata.79044.v2/t5

Integrated $\eta$/$\pi^{0}$ ratio produced in inelastic pp collisions at center of mass energies of 2.76 and 8 TeV.

• #### Table 6

Data from Table 6

10.17182/hepdata.79044.v2/t6

Mean transverse momenta $\langle p_\text{T}\rangle$ of $\pi^{0}$ mesons produced in inelastic pp collisions at center of mass energies of 2.76...

• #### Table 7

Data from Table 6

10.17182/hepdata.79044.v2/t7

Mean transverse momenta $\langle p_\text{T}\rangle$ of $\eta$ mesons produced in inelastic pp collisions at center of mass energies of 2.76...

• #### Table 8

Data from Fig. 8

10.17182/hepdata.79044.v2/t8

The measured ratio of cross sections for inclusive $\eta$ to $\pi^{0}$ production at a center of mass energy of 8...

Version 2 modifications: Data review