Nonlinear Phenomena in Complex Systems, 2025, Vol.28, No.4, pp.334

NONLINEAR PHENOMENA IN COMPLEX SYSTEMS
An Interdisciplinary Journal

2025, Vol.28, No.4, pp.334 - 348

Measurement of the e⁺e^-→ π⁺π^-π⁰ Cross Section in the Energy Range √s = 760 – 798 MeV with CMD-3 Detector Based on Data from the Tracking System and Its Contribution to the Muon (g – 2) Hadronic Term

Dz. V. Shoukavy, D. S. Vasileuskaya, G. V. Fedotovich, D. N. Grigoriev, A. E. Ryzhenenkov, and S. S. Tolmachev

The cross section of the process e⁺e^-→ π⁺π^-π⁰ has been measured with the Cryogenic Magnetic Detector (CMD-3) at the electron-positron collider VEPP-2000. The measurement is based on data samples that were collected in the center-of-mass energy range √s = 760 – 798 MeV corresponding to an integrated luminosity of L_int = 18:4 pb⁻¹, covering the kinematic region of the ω(782) isoscalar resonance. The total systematic uncertainty of the cross section measurement is about 2%, dominated by the luminosity determination uncertainty of 1.5%. The results are compared with the previous most precise measurements from experiments. The measured cross section is used to evaluate the leading-order hadronic vacuum polarization contribution of the 3π channel to the muon anomalous magnetic moment (a_μ^3π:).

Key words: process e⁺e^-→ π⁺π^-π⁰, Born cross section, CMD-3 detector, muon anomalous magnetic moment

DOI: https://doi.org/10.5281/zenodo.17949372

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