Cross sections for e+e−→hadrons, e+e−, and μ+μ− near 3684 MeV are presented. The ψ(3684) resonance is established as having the assignment JPC=1−−. The mass is 3684 ± 5 MeV. The partial width for decay to electrons is Γe=2.1±0.3 keV and the total width is Γ=228±56 keV.
No description provided.
We have found events of the form e++e−→e±+μ∓+missingenergy, in which no other charged particles or photons are detected. Most of these events are detected at or above a center-of-mass energy of 4 GeV. The missing-energy and missing-momentum spectra require that at least two additional particles be produced in each event. We have no conventional explanation for these events.
X IN RE INCLUDES TWO OR MORE UNDETECTED PARTICLES.
We have searched for possible narrow resonances produced in e + e − annihilation at Adone, in the mass regions 1910–2545 MeV and 2970–3090 MeV. No evidence has been found for narrow resonances, within the sensitivity of the present work: we deduce an upper limit on the energy integrated resonant cross section of about 10% of the J/ψ(3100) corresponding value.
No description provided.
The reactions e + e − → hadrons and e + e + e − →e + e − have been studied at the J/gY (3100) resonance). The relative weights of the topological cross sections for fixed charged multiplicity are σ 2 =(32±5)%, σ 4 =(49±8)%, σ 6 =(18±3)%, and σ 8 =(1±0.6)%. The average pion multiplicities are 〈 n ch 〉=3.8±0.3 and 〈n π o 〉=3.1±0.8 . The decay widths are Γ e =(4.6±0.8) keV, Γ h =(59±24) keV, and Γ =(68±26) keV.
CROSS SECTION AROUND RESONANCE.
CROSS SECTION JUST BELOW J/PSI.
MULTIPLICITY AT J/PSI.
Differential cross sections have been measured at Fermilab with a focusing spectrometer for π±p, K±p, and p±p elastic scattering at 50-, 70-, 100-, 140-, and 175-GeV/c incident momentum over the |t| range 0.03 to 0.8 GeV2. The results are smooth in t and are parametrized by quadratic exponential fits.
DATA PRESENTED AGAIN IN LATER PAPER.
We have measured differential cross sections for K−p→Σ+π− and π−p→pπ− at 3.0 and 5.1 GeV/c near the backward direction. At 3.0 GeV/c both have a dip near −u∼0.1 (GeV/c)2. At 5.1 GeV/c, dσdu for π−p→pπ− falls exponentially with slope 3.8±0.1 (GeV/c)−2 whereas dudσ for K−p→Σ+π− exhibits a decreasing slope for larger |u|. These data are discussed in terms of SU(3), and the relative importance of the helicity-flip and -non-flip amplitudes is investigated.
No description provided.
The spin rotation parameter R has been measured for elastic π − p scattering at 40 GeV/ c , at four momentum transfers t ranging from −0.19 to −0.52 (GeV/ c ) 2 . The average value within this interval is R π − p = -0.200± 0.023. The resulting constraints on the πN scattering amplitudes are discussed. The experiments also yields an average value for K − p scattering, R K − p scattering, R K − p = -0.16±0.16.
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New experimental results are presented on proton-proton elastic scattering at centre-of-mass energies s =23 GeV and s =62 GeV . The data are obtained using the Split Field Magnet detector at the CERN Intersecting Storage Rings. The absolute differential cross-sections show an energy-dependent behaviour. The position of the diffraction minimum changes from t =(−1.44±0.02)GeV 2 at 23 GeV to (−1.26±0.03)GeV 2 at 62 GeV. The cross-section at the second maximum is increasing with s . The connection of these observations with the hypothesis of “geometrical scaling” is discussed.
63 K EVENTS.
380 K EVENTS.
We report final results on the polarization parameter P in elastic scattering of π − , K − and antiprotons at 40 GeV/ c incident momentum. The energy dependence of P (t) in π − p above 10 GeV/ c is well fitted by P (t) α s αR(t)-α P (t) where α R (t) are the effective Regge and Pomeron trajectories respectively. The data in K − p are compatible with exchange degeneracy. The results inp¯p show an important structure for |t|> 0.3 (GeV/c) 2 demonstrating the existence of a large helicity flip amplitude.
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Antiproton-proton elastic scattering data at 6.2 GeV/ c in the range 0.3 (GeV/ c ) 2 ⩽ − t ⩽ 10.0 (GeV/ c ) 2 is presented. The experiment, using spark chambers and proportional chambers, was performed at the CERN Proton Synchroton.
No description provided.
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