Physics case for low-$\sqrt{s}$ QCD studies at FCC-ee, by David d'Enterria, Pier Francesco Monni, Peter Skands, Andrii Verbytskyi

SciPost Physics Home Authoring Refereeing Submit a manuscript About Physics case for low-$\sqrt{s}$ QCD studies at FCC-ee David d'Enterria, Pier Francesco Monni, Peter Skands, Andrii Verbytskyi SciPost Phys. 20, 092 (2026) · published 30 March 2026 doi: 10.21468/SciPostPhys.20.3.092 pdf BiBTeX RIS Submissions/Reports Abstract Measurements of hadronic final states in $e^{+}e^{-}$ collisions at centre-of-mass (CM) energies below the Z peak can notably extend the FCC-ee physics reach in terms of precision quantum chromodynamics (QCD) studies. Hadronic final states can be studied over a range of hadronic energies $\sqrt{s_\mathrm{had}} ≈ 20-80\,\mathrm{GeV}$ by exploiting events with hard initial- and final-state QED radiation (ISR/FSR) during the high-luminosity Z-pole run, as well as in dedicated short (about one month long) $e^{+}e^{-}$ runs at CM energies $\sqrt{s} ≈ 40\,\mathrm{GeV}$ and $60\,\mathrm{GeV}$. Using realistic estimates and fast detector simulations, we show that data samples of about $10^{9}$ hadronic events can be collected at the FCC-ee at each of the low-CM-energy points. Such datasets can be exploited in a variety of precision QCD measurements, including studies of light-, heavy-quark and gluon jet properties, hadronic event shapes, fragmentation functions, and nonperturbative dynamics. This will offer valuable insights into strong interaction physics, complementing data from nominal FCC-ee runs at higher center-of-mass energies, $\sqrt{s} ≈ 91, 160, 240,$ and $365\,\mathrm{GeV}$. × TY - JOURPB - SciPost FoundationDO - 10.21468/SciPostPhys.20.3.092TI - Physics case for low-$\sqrt{s}$ QCD studies at FCC-eePY - 2026/03/30UR - https://scipost.org/SciPostPhys.20.3.092JF - SciPost PhysicsJA - SciPost Phys.VL - 20IS - 3SP - 092A1 - d'Enterria, DavidAU - Monni, Pier FrancescoAU - Skands, PeterAU - Verbytskyi, AndriiAB - Measurements of hadronic final states in $e^{+}e^{-}$ collisions at centre-of-mass (CM) energies below the Z peak can notably extend the FCC-ee physics reach in terms of precision quantum chromodynamics (QCD) studies. Hadronic final states can be studied over a range of hadronic energies $\sqrt{s_\mathrm{had}} ≈ 20-80\,\mathrm{GeV}$ by exploiting events with hard initial- and final-state QED radiation (ISR/FSR) during the high-luminosity Z-pole run, as well as in dedicated short (about one month long) $e^{+}e^{-}$ runs at CM energies $\sqrt{s} ≈ 40\,\mathrm{GeV}$ and $60\,\mathrm{GeV}$. Using realistic estimates and fast detector simulations, we show that data samples of about $10^{9}$ hadronic events can be collected at the FCC-ee at each of the low-CM-energy points. Such datasets can be exploited in a variety of precision QCD measurements, including studies of light-, heavy-quark and gluon jet properties, hadronic event shapes, fragmentation functions, and nonperturbative dynamics. This will offer valuable insights into strong interaction physics, complementing data from nominal FCC-ee runs at higher center-of-mass energies, $\sqrt{s} ≈ 91, 160, 240,$ and $365\,\mathrm{GeV}$.ER - × @Article{10.21468/SciPostPhys.20.3.092, title={{Physics case for low-$\sqrt{s}$ QCD studies at FCC-ee}}, author={David d'Enterria and Pier Francesco Monni and Peter Skands and Andrii Verbytskyi}, journal={SciPost Phys.}, volume={20}, pages={092}, year={2026}, publisher={SciPost}, doi={10.21468/SciPostPhys.20.3.092}, url={https://scipost.org/10.21468/SciPostPhys.20.3.092},} Ontology / Topics See full Ontology or Topics database. Quantum chromodynamics (QCD) Authors / Affiliations: mappings to Contributors and Organizations See all Organizations. 1 David d'Enterria, 2 Pier Francesco Monni, 2 Peter Skands, 3 Andrii Verbytskyi 1 Max-Planck-Institut für Physik / Max Planck Institute for Physics [MPP] 2 Organisation européenne pour la recherche nucléaire / European Organization for Nuclear Research [CERN] 3 Monash University Funders for the research work leading to this publication Australian Research Council [ARC] European Research Council [ERC]