At the Bonn 2.5.GeV electron synchrotron the target asymmetry for the photoproduction of positive pions has been measured. Data were taken at photon energies between 0.7 and 2.2 GeV and a pion CM-angle of 65°.
Axis error includes +- 0.0/0.0 contribution (?////).
No description provided.
We have searched the mass region 3.2 to 5.9 GeV for evidence of narrow resonances in e+e−→hadrons. We find no evidence for any such resonances other than the ψ(3695) in this region with a sensitivity ranging from about 12 to 45% of the integrated cross section of the ψ(3695). The more stringent bounds apply to resonances of a few MeV width, while the looser bounds apply to resonances of up to 20 MeV width.
EXTREAMLY GOOD DATA, MUST BE ASCED FROM AUTHORS.
The total cross section for hadron production by e+e− annihilation has been measured at center-of-mass energies between 2.4 and 5.0 GeV. Aside from the very narrow resonances ψ(3105) and ψ(3695), the cross section varies between 32 and 17 nb over this region with structure in the vicinity of 4.1 GeV.
No description provided.
MEAN CHARGED MULTIPLICITY. ERRORS ARE STATISTICAL ONLY.
The pπ+π0 and pπ+π+π− final states from π+p interactions at 3.9 GeV/c have been analyzed by the prism-plot technique and the following three quasi-two-body channels have been studied in detail: π+p→ρ+p, π+p→π0Δ++, and π+p→ρ0Δ++. Results are presented on cross sections, differential cross sections, and single and joint spin density matrix elements. These are compared with the Dar-Watts-Weisskopf absorption model and Reggeized pion-exchange model predictions. Relations among joint spin density matrix elements for ρ0Δ++ are compared with quark-model predictions.
No description provided.
No description provided.
Inclusive cross sections and one-particle inclusive spectra are given for neutral K, Λ and Λ produced in K − p and K + p interactions at 32 GeV/ c in the 4.5 m Mirabelle hydrogen bubble chamber at the Serpukhov accelerator. Cross sections for associated production are also given, and the energy dependences of the cross sections and of the x distributions in the central and in the fragmentation regions are discussed.
No description provided.
No description provided.
Inclusive cross sections and longitudinal momentum distributions are presented for γ rays produced in K − p and K + p interactions at 32 GeV/c in the 4.5 m Mirabelle hydrogen bubble chamber at the Serpukhov accelerator. The average longitudinal and transverse momentum of neutral pions and the average π 0 multiplicity ▪ 〈 n π 0〉 are estimated. It is found that 〈 n π 0〉 is an increasing function of the number of charged prongs.
No description provided.
No description provided.
For the first time, the reactions π + p →K + ∑ + and K − p→ π − ∑ + have been studied in the same apparatus. This has been done at an adequately high momentum (10.1 GeV/ c ) to allow a check of the prediction of exchange degeneracy, that the differential cross sections should be converging at high energy. We have measured the cross section for momentum transfers t between t min and t = −0.3 (GeV/ c ) 2 . We find that for both reactions the differential cross section shows an exponential fall, with no deviations right in to t = t min (where some other experiments have shown a dip in the cross section). Furthermore, we find the magnitude of the differential cross sections to be closely similar at t = 0, with a ratio R= ( d σ d t) t=0 ( K − p →π − ∑ + ) ( d σ d t) t=0 (π + p → K + ∑ + However, the slope for the positive reaction is about 19% steeper than that for the negative reaction.
No description provided.
We have measured p−d inelastic scattering at small momentum transfer by detecting the slow-recoil deuterons from a deuterium-gas-jet target. The coherent diffraction dissociation of protons on deuterons was studied in the region 0.03<|t|<0.07 (GeV/c)2, 1.4<MX2<4 GeV2, and for energies from 50 to 275 GeV. In this region, the diffractive cross section exhibits structure and is dominated by an enhancement at MX2∼1.9 GeV2.
No description provided.
No description provided.
No description provided.
We present cross sections for e+e−→hadrons, e+e−, and μ+μ− near 3095 MeV. The ψ(3095) resonance is established as having an assignment JPC=1−−. The mass is 3095 ±4 MeV. The partial width to electrons is Γe=4.8±0.6 keV and the total width Γ=69±15 keV. Total rates and interference measurements for the lepton channels are in accord with μ−e universality.
No description provided.
The analysis of 1466 events of the type e + e − → μ ± μ ± , in the time-lifke range from 1.44 to 9.00 GeV 2 , sh that the absolute value of the cross-section and its energy dependence follow QED expectations within (± 3.2%) and (± 1.2%), respectively.
The cross section of the reaction $e^+ e^- \to \mu^\pm \mu^\mp$ integrated over the experimental apparatus at 14 values of the colliding beam energy $E$ corresponding to total centre-of-mass energy $\sqrt{s}=2E$ from 1.2 to 3.0 GeV.
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