188宝金博页面版

JHEP08(2025)035Published for SISSA by SpringerReceived: December 11, 2024Accepted: July 3, 2025Published: August 5, 2025Light neutral-meson production in pp collisions at√ s = 13 TeVThe ALICE collaborationE-mail: alice-publications@cern.chAbstract: The momentum-dif f erential invariant cross sections of π 0 and η mesons arereported for pp collisions at√ s= 13TeV at midrapidity ( |y| < 0 . 8). The measurement isperformed in a broad transverse-momentum range of 0 . 2 < p T < 200GeV/ c and 0 . 4 < p T <60GeV/ c for the π 0 and η , respectively, extending the p T coverage of previous measurements.Transverse-mass-scaling violation of up to 60% at low transverse momentum has been observed,agreeing with measurements at lower collision energies. Transverse Bjorken x ( x T ) scaling ofthe π 0 cross sections at LHC energies is fulf i lled with a power-law exponent of n = 5 . 01 ± 0 . 05,consistent with values obtained for charged pions at similar collision energies. The data arecompared to predictions from next-to-leading order perturbative QCD calculations, wherethe π 0 spectrum is best described using the CT18 parton distribution function and theNNFF1.0 or BDSS fragmentation function. Expectations from PYTHIA8 and EPOS LHCoverestimate the spectrum for the π 0 and are not able to describe the shape and magnitudeof the η spectrum. The charged-particle multiplicity dependent π 0 and η p T spectra showthe expected change of the spectral shape, characterized by a f l atter slope with increasingmultiplicity. This is demonstrated across a broad transverse-momentum range and up toevents with a charged-particle multiplicity exceeding f i ve times the mean value in minimumbias collisions. The η/π 0 ratio depends on the charged-particle multiplicity for p T < 4GeV/ c .PYTHIA8 and EPOS LHC qualitatively explain this behavior with an increasing contributionfrom the feed-down of heavier particles to the π 0 spectrum.Keywords: Hadron-Hadron Scattering, Particle and Resonance Production, QCDArXiv ePrint: 2411.09560Open Access, Copyright CERN,for the benef i t of the ALICE Collaboration.Article funded by SCOAP 3 .https://doi.org/10.1007/JHEP08(2025)035