- Andreotti, M
- Bagnasco, S
- Baldini, W
- Bettoni, D
- Borreani, G
- Buzzo, A
- Calabrese, R
- Cester, R
- Cibinetto, G
- Dalpiaz, P
- Garzoglio, G
- Gollwitzer, KE
- Graham, M
- Hu, M
- Joffe, D
- Kasper, J
- Lasio, G
- Lo Vetere, M
- Luppi, E
- Macrì, M
- Mandelkern, M
- Marchetto, F
- Marinelli, M
- Menichetti, E
- Metreveli, Z
- Mussa, R
- Negrini, M
- Obertino, MM
- Pallavicini, M
- Pastrone, N
- Patrignani, C
- Pordes, S
- Robutti, E
- Roethel, W
- Rosen, J
- Rumerio, P
- Rusack, RW
- Santroni, A
- Schultz, J
- Seo, SH
- Seth, KK
- Stancari, G
- Stancari, M
- Tomaradze, A
- Uman, I
- Vidnovic, T
- Werkema, S
- Zweber, P
- et al.
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