Joachim Hansen

This study presents the first measurement of the f1(1285) resonance using the ALICE detector in inelastic proton–proton collisions at a center-of-mass energy of 13 TeV. The resonance is reconstructed at midrapidity (|y|< 0.5) through the hadronic decay channel f1(1285)→KS0K±π∓. Key measurements include the determination of its mass, transverse-momentum integrated yield, and average transverse momentum. Additionally, the ratio of the transverse-momentum integrated yield of f1(1285) to pion is compared with calculations from the canonical statistical hadronization model. The model calculation, assuming a zero total strangeness content for f1(1285), reproduces the data within 1σ deviation, shedding light on the quark composition of f1(1285). © 2025 CERN for the benefit of the ALICE Collaboration