v 1 6 M ar 2 00 7 Precision measurements of the total and partial widths of the ψ ( 2 S ) charmonium meson with a new complementary - scan technique
نویسندگان
چکیده
We present new precision measurements of the ψ(2S) 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. It relies on precise revolution-frequency and orbit-length measurements, while making the analysis of the excitation curve almost independent of machine lattice parameters. For the ψ(2S) meson, by studying the processes p̄p → e+e− and p̄p → J/ψ + X → e+e− + X , we measure the width Γ = 290± 25(sta)± 4(sys) keV and the combination of partial widths Γe+e−Γ p̄p/Γ = 579± 38(sta)± 36(sys) meV, which represent the most precise measurements to date. Preprint submitted to Elsevier 28 February 2008
منابع مشابه
v 2 2 7 Se p 20 07 Precision measurements of the total and partial widths of the ψ ( 2 S ) charmonium meson with a new complementary - scan technique in p̄p annihilations
We present new precision measurements of the ψ(2S) 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 ...
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