Nuclear modification factor of light neutral-meson spectra up to high transverse momentum in p-Pb collisions at $\mathbf{\sqrt{s_{NN}}}$ = 8.16 TeV
- Acharya, Shreyasi et al
- arXiv:2104.03116CERN-EP-2021-053
 | Shower shape distribution for the elongation $\sigma_\mathrm{long}^2$ in PYTHIA 8 Monte Carlo simulations a) showing the various contributions to the full cluster sample for a high $\pT$ example interval and b) compared to the $\sigma_\mathrm{long}^2$ distribution in data in the same $\pT$ interval. |
 | Ratio of the neutral pion invariant differential cross sections to the two-component model (TCM) fit of the combined spectrum for the different reconstruction techniques PCM, PCM-EMC, EMC, PHOS and mEMC in \pPb\ collisions at \sU. Statistical uncertainties are given by the vertical error bars while systematic uncertainties are shown as boxes. |
 | Neutral pion~a) and $\eta$ meson~d) \com{invariant differential} cross sections for \pp\ collisions at $\sUp$ and $\pPb$ collisions at $\sU$ together with TCM fits, NLO calculations~\cite{deFlorian:2014xna,Aidala:2010bn,Bertone:2017tyb} and PYTHIA~8~\cite{Sjostrand:2007gs,Skands:2014pea} predictions using different (n)PDFs~\cite{Kovarik:2015cma,Eskola:2016oht,Hou:2019efy}. Statistical uncertainties are shown as vertical bars; the systematic uncertainties as boxes. The ratios of the $\pz$ spectra in \pPb\ and \pp\ collisions to the TCM fits are shown in panel b) and c), respectively, together with the ratios of the calculations to the fits; panel~e) shows the same for $\eta$ mesons in \pPb\ collisions. In panel f) the $\eta/\pi^0$ ratios in \pp\ and \pPb\ collisions are compared to theory predictions. The normalization uncertainty in the spectra ratio panels is indicated as a solid gray box around unity. |
 | a)~$\rpp$ for $\pz$ and $\eta$ mesons in \pPb\ collisions at $\sU$ together with NLO~\cite{Eskola:2016oht,Kovarik:2015cma}, CGC~\cite{Lappi:2013zma} and FCEL~\cite{Arleo:2020hat} predictions. b)~$\rpp$ for $\pz$ at $\sU$ compared with $\pz$~\cite{Acharya:2018hzf} and charged hadron measurements~\cite{Acharya:2018qsh,Khachatryan:2016odn} at $\snn=5.02$ TeV. c)~Ratio of the $\pz$ $\rpp$ at $\sU$ to that at $\snn=5.02$ TeV together with corresponding CGC and FCEL model predictions. Statistical uncertainties are shown as vertical bars; the systematic uncertainties as boxes. The overall normalization uncertainties are indicated as solid boxes around unity and amount to 3.4\% in a) and b), and to 6.2\% in c). |