We present new precision measurements of the ψ (2 S) total and partial widths from excitation curves obtained in antiproton-proton annihilations by Fermilab experiment E835 at the Antiproton Accumulator in the year 2000. A new technique of complementary scans was developed to study narrow resonances with stochastically cooled antiproton beams. The technique relies on precise revolution-frequency and orbit-length measurements, while making the analysis of the excitation curve almost independent of machine lattice parameters. We study the ψ (2 S) meson through the processes over(p, ̄) p → e e and over(p, ̄) p → J / ψ + X → e e + X. We measure the width to be Γ = 290 ± 25 (sta) ± 4 (sys)   keV and the combination of partial widths Γ Γ / Γ = 579 ± 38 (sta) ± 36 (sys)   meV, which represent the most precise measurements to date. © 2007 Elsevier B.V. All rights reserved. + - + - e+ e- over(p, ̄) p