Precision measurements of charmonium states formed in pp\uaf annihilation

ermilab experiment E-760 studies the resonant formation of charmonium states in proton-antiproton interactions using a hydrogen gas-jet target in the Antiproton Accumulator ring at Fermilab. Precision measurements of the mass and width of the charmonium states \u3c7c1,\u3c7c2, a direct measurement of the \u3c8\u2019 width, and a new precision measurement of the J/\u3c8 mass are presented

A NEW MEASUREMENT OF THE PROTON ELECTROMAGNETIC FORM-FACTOR IN THE TIME-LIKE REGION AT HIGH-ENERGY RID C-5223-2009

We have determined the value of the proton electromagnetic form factor in the time-like region at -q2 = 12.6 (GeV/c)2. The events ppBAR --> e+e- from the data collected by the E760 experiment. performed at the Antiproton Accumulator Ring at Fermilab, were used. At the value of -q2, assuming the possibility of neglecting the \G(E)\ contribution to the cross section, we found \G(M) \ = 0.0015 +/- 0.003 and sigma(TOT) (ppBAR --> e+e-) = 1.9 +/- 0.8 pb

RECENT RESULTS IN LIGHT-QUARK MESON SPECTROSCOPY FROM FERMILAB EXPERIMENT E-760 RID C-5223-2009

Fermilab experiment E-760 light-quark meson spectroscopy data for proton-antiproton annihilation to 3pi0, 2pi0eta, pi02eta, and 3eta in-flight have confirmed the 1500 MeV state at rest seen previously at CERN. Structures above this energy are complex, and preliminary results of amplitude analysis, in progress, for extracting spin quantum numbers show the possibility of nearly degenerate states for some of these structures

Experimental determination of the proton electromagnetic form factor at Q2 = 12.4 (GeV/c)2

The value of the proton form factor in the time-like region has been determined at Q2=12.4(GeV/c)2. We have selected events pp¯→e+e- from the data collected in an experiment performed at the Antiproton Accumulator Ring at Fermilab and, assuming the validity of the ‖GE‖≊0 hypotesis, we have found ‖GM‖=.034±.017 and σTOT(pp¯→e+e-)=10±5pb

PRODUCTION OF THE F(2)(1520) RESONANCE IN ANTIPROTON PROTON ANNIHILATIONS AT ROOT-S=2980 AND 3526 MEV RID C-5223-2009

We present measurements of the 2pi0 mass spectrum in proton-antiproton annihilations. The f2 (1520) resonance is strongly produced in the 3pi0 channel. Its production along with an eta is observed, but strongly suppressed. Other features are seen in the data, including the f2 (1270) and structures at 2000 MeV/c2 and above

Formation of (c cbar) states from antiproton-proton annihilations in the Fermilab accumulator (E760)

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MEASUREMENT OF THE GAMMA-GAMMA-PARTIAL WIDTH OF THE CHI-2 CHARMONIUM RESONANCE RID C-5223-2009

The E760 Collaboration has studied the reaction ppBAR --> chi2 --> gammagamma using a hydrogen gas jet target in the Fermilab antiproton accumulator ring. The following values are obtained for the branching ratio and partial width to two photons; B(chi2 --> gammagamma) = (1.60 +/- 0.45) X 10(-4) and GAMMA(chi2 --> gammagamma) = 321 +/- 95 eV