Results are reported on K − -neutron interactions at c.m. energies near 2 GeV. The interactions are dominated by strong production of hyperon resonances, particularly Σ(1385), Λ(1405) and Λ(1520). Production cross sections and angular distributions are given for the Σ(1385), Λ(1405) and Λ(1520) and branching fractions to decay modes observed in the experiment are given for Σ(1385) and Λ(1520). The strong energy dependence of some features of the data suggests that s -channel effects are dominant.
No description provided.
RESONANCE CROSS SECTIONS FOR <K- PI- P> FINAL STATE.
RESONANCE CROSS SECTIONS FOR <AK0 PI- N> FINAL STATE.
We report on coherent interactions in a 2.5 event/μb K − d exposure. The predominant channel studied is K − d → K − π + gp − d (415 events). We find strong Q- and L-production in the (K ππ ) system. The production mechanism determines I = 1 2 for both enhancements and a spin-parity in the series 0 − , 1 + ,2 − … . A spin-parity analysis shows the Q to be a 1 + object, while the L is 1 + or 2 − , although a higher spin cannot be excluded. The cross sections for Q and L production and other final states are presented.
CORRECTED FOR UNSEEN RECOIL DEUTERONS BY EXTRAPOLATION. (UNCORRECTED CROSS SECTIONS ARE THOSE OBSERVED WITH P(DEUT) > 140 MEV/C).
From a 3.5 ev/μb exposure of the BNL 80 inch chamber filled with deuterium to a 7.0 GeV/ c p beam we obtained 664 events in the channel p n → p π − p . The channel cross section is (1270 ± 110 60 ) μb. The final state is dominated by Δ (1230) production. The experimental data is well described by a one-pion exchange model with off-mass shell corrections.
No description provided.
For the reaction π + p → ωΔ ++ data on the total cross section ( σ = 61 ± 12 μ b), differential cross sections, spin density matrix elements and statistical tensor elements are given. We observe natural and unnatural parity exchange contributions to the total cross section. We note that the value of ϱ 00 is not zero and in the helicity frame exhibits a dip at t ≈ −0.25 (GeV/ c ) 2 . A qualitative theoretical discussion of our results is presented.
CORRECTED FOR BACKGROUND, RESONANCE TAILS AND UNSEEN OMEGA DECAY MODES.
NORMALIZED TO THE TOTAL CROSS SECTION. SOME BACKGROUND IS PRESENT.
NORMALIZED TO THE TOTAL CROSS SECTION. SOME BACKGROUND IS PRESENT.
The total cross sections of 4 He, 6 Li, 7 Li, 9 Be, 12 C and 32 S for positive and negative pions have been measured in the energy range 80 to 260 MeV in a transmission experiment. Coulomb corrections were applied using real parts of the forward nuclear amplitudes as determined from dispersion relations. At the lower energies there remain large residual differences between the π + and π − scattering on the isoscalar nuclei. These can be largely understood in terms of the Coulomb distortion.
No description provided.
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No description provided.
Measurements of K + p elastic scattering have been carried out at 13 momenta between 432 MeV/ c and 939 MeV/ c using spark chambers. The data establish unambiguously the constructive interference of the Coulomb and nuclear amplitudes at 432 MeV/ c . The elastic cross section is found to be independent of momentum through the range covered. The phase shifts for S, P, D and F waves are obtained in an energy dependent analysis in which higher waves are held at theoretical values. The initial behaviour ofthe P, D and F amplitudes is quite close to that predicted by the calculation of the peripheral partial waves. Only the P3 and D5 amplitudes become strikingly different with increasing momentum.
COULOMB INTERFERENCE EFFECT SEEN AT SMALL ANGLES.
No description provided.
No description provided.
Results are presented for the quasi two-body hypercharge exchange reactions of the type using data from a high statistics bubble chamber experiment. Total and differential cross sections and the momentum transfer dependence of the meson and hyperon resonance single density matrix elements are discussed. Amplitude analyses are performed for the first two reactions. The results are compared with quark model and duality predictions and with those from other related reactions.
No description provided.
No description provided.
No description provided.
A partial wave analysis of the K 0 π + π − system produced in the charge exchange reaction K − p → ( K 0 π + π − ) n at 4.2 GeV/ c has been performed both as a function of Kππ mass and of t ′. The 1 + S wave forms the largest contribution to the K ππ system and peaks at roughly the same mass as the Q in diffractive K ππ production. The polarization properties of the 1 + S ( K ∗ π) and 1 + S (Kϱ) waves differ fromt those of the diffractive 1 + wave. There is some evidence for a resonance contribution to 1 + S ( K ∗ π) . The strong 2 + wave the K ∗ (1420) and the K ϱ/ K ∗ ϱ decay branching ratio determined to be 0.36±0.10. An enhancement with spin-parity 1 − is observed under K ∗ (1420) .
CROSS SECTION CORRECTED FOR BREIT-WIGNER TAILS, THE TP CUT, UNSEEN <AK0 PI> AND <K RHO> DECAY MODES. BRANCHING RATIO K*(1420) --> <K RHO>/<K* PI> = 0.36 +- 0.10.
No description provided.
Properties of Σ ± (1385) inclusively produced in 4.2 GeV/ c K − p interactions are studied. Inclusive cross sections are presented together with differential cross sections as functions of x and p t 2 for both Σ + (1385) and Σ − (1385). The complete density matrix for Σ + (1385) production at small momentum transfer is studied as a function of t and of recoil mass MM 2 . Substantial agreement with the predictions of the additive quark model is found. The Σ + (1385) production in the target fragmentation region is studied in the framework of the triple-Regge model.
Axis error includes +- 5/5 contribution (ERROR OF NORMALIZATION).
Axis error includes +- 5/5 contribution (ERROR OF NORMALIZATION).
Axis error includes +- 5/5 contribution (ERROR OF NORMALIZATION).
New bubble chamber data on the reactions K − n → π 0 Σ 0 in the c.m. energy range 1750–2200 MeV are presented and are compared with the predictions of the most recent partial-wave analysis of the reaction K N → πΣ . The comparison stresses the need for data involving a single value of isotopic spin in the study of this reaction. An analysis of the new data yields two satisfactory solutions involving only well established resonances.
No description provided.
FERMI MOTION OF NEUTRON USED TO EXTRACT ENERGY DEPENDENCE.
NORMALIZED LEGENDRE COEFFICIENTS OF CROSS SECTION ANGULAR DISTRIBUTION.
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