Electroproduction of hadrons is studied in the kinematic region W < 2.8 GeV and 0.3 < Q 2 < 1.4 GeV 2 using the DESY streamer chamber. Prong cross sections, charged-particle multiplicities and inclusive π − distributions are presented. The average charged multiplicity is found to be independent of Q 2 in the Q 2 range studied here; however it is lower than in photoproduction. The fraction of forward π − is found to be significantly less in electroproduction than in photoproduction. The 〈 p ⊥ 2 〉 for inclusive π − is, for all x values, similar to that found in photoproduction.
No description provided.
No description provided.
No description provided.
A clear, prompt dimuon signal has been observed in a low-statistics streamer-chamber experiment with 16-GeV/c πp interactions. The good mass resolution makes it possible to identify the contributions from ρ and ω decays and η and ω Dalitz decays. An excess of events is observed in the mass region ∼400-600 MeV which is not accounted for by the above-mentioned decays.
The data with PI+- beam obtained from the combination of PI+ and PI- beams.
Antiproton-proton total elastic cross sections at 21 incident momenta in the range 0.69 to 2.43 GeV/ c have been deduced by combining p̄p elastic differential cross sections over a c.m. angular range −0.95 ⩽ cos θ ∗ ⩽ 0.93 with forward elastic cross sections derived from recent real-part measurements and p̄p total cross sections. Two bumps are observed, at M 1 ⋍ 2.155 and M 2 ⋍ 2.345 GeV /c 2 , having widths of Г 1 ∼ 0.135 and Г 2 ∼ 0.135 GeV /c 2 . Corresponding structures in other p̄p reaction channels are discussed.
Axis error includes +- 4/4 contribution.
n p annihilations with ⩾ 3 prongs with an incident antineutron momentum between 0.5 and 0.8 GeV/ c are analysed. We present the topological branching ratios and cross sections, the resonance production rates and possible ϱ-ω interference effects.
CHANNEL FRACTIONS IN <2PI+ PI- PI0> FINAL STATE.
We present results from an experiment studying the production of single particles and jets (groups of particles) with high p ⊥ (transverse momentum) in 200 GeV/ c interactions on a beryllium target. We give a detailed discussion of the ambiguities in the jet definition. The jet and single-particle cross sections have a similar shape but the jet cross section is over two orders of magnitude larger. The events show evidence for the coplanar structure suggested by constituent models, and the momentum distributions of charged particles give strong support to a simple quark-quark scattering model.
NOMINAL CALORIMETER THRESHOLD WAS 3 GEV/C. AT WHICH PT TRIGGER EFFICIENCY SHOULD BE 50 PCT. THIS DATA HAS AN ADDITIONAL 20 PCT. NORMALISATION ERROR.
THIS TABLE REFERS TO JET WITH THRESHOLD OF 3 GEV/C. THE JET PONTS ARE AVERAGED OVER ROUGHLY EQUAL AMOUNTS OF +VE AND -VE BEAMS.
THIS TABLE REFERS TO JET WITH THRESHOLD OF 4 GEV/C. THE JET PONTS ARE AVERAGED OVER ROUGHLY EQUAL AMOUNTS OF +VE AND -VE BEAMS.
New experimental results on the reactions K L 0 p→K S 0 p, Λπ + , Σ 0 π + andΛπ + π 0 at c.m. energies between 1.54 and 1.71 GeV are presented. This experiment has a statistical accuracy comparable with or greater than corresponding K − p and K − d experiments in the same energy range and a comparison with the data from these different types of experiments has been made. A search has been made for narrow states with masses in the region of 1.58 GeV.
No description provided.
No description provided.
No description provided.
None
FOR THE FPRIME A PURE 2+ STATE IS ASSUMED AND ONLY JZ=+1,0,-1 CONTRIBUTIONS ARE CONSIDERED.
No description provided.
No description provided.
We have studied the coherent dissociation of neutrons into pπ− systems, for a variety of nuclear targets, at incident momenta up to 300 GeV/c. Using a model incorporating both electromagnetic and hadronic production, we have extracted total cross sections for scattering of unstable pπ− systems on nucleons.
No description provided.
The charged-current cross sections for neutrinos and antineutrinos on nucleons in the energy range 20–200 GeV are given. Taken in conjunction with the previous Gargamelle results, they show that σ E is almost constant with energy for antineutrinos, and falls with energy for neutrinos. The value of 〈q 2 〉 E decreases with energy for both neutrinos and antineutrinos, and these deviations from exact Bjorken scaling are consistent with those observed in electron and muon inelastic scattering. We find no evidence for new heavy quark states with right-handed coupling.
Measured charged current total cross section.
Measured charged current total cross section.
We present the results of a search at Fermilab for the charmed meson, D∘(1865), produced in association with a prompt muon by 300-GeV/c neutrons. We observe no significant enhancement in high-mass K±π∓ systems and report, at the 95% confidence level, an upper limit of 200 nb/nucleon for the production of a pair of charmed particles and their subsequent decay into a K±π∓ state and a prompt muon.
The cross section for D0 and CHARM particle production is obtained with theassumption that BR(D0 --> K- PI+) = 3 PCT and BR(CHARM --> MU+ X) = 15 PCT.
Forum