Cross sections, differential cross sections, density matrix elements and statistical tensors are given for the reactions π + p → ( ϱ 0 , ω ) Δ ++ at 13.2 GeV/ c . A discussion of the results in terms of particle exchanges, quark model or dipole coupling constraints, and the equal phase hypothesis is presented in some detail for the high statistics ϱ 0 Δ ++ channel.
BREIT-WIGNER FITS WHICH CORRECT FOR RESONANCE TAILS AND BACKGROUNDS.
No description provided.
JACKSON FRAME DENSITY MATRIX ELEMENTS.
A recent spin-parity analysis of the π + π + π − system formed opposite a proton and a coherent deuteron by incident 13 GeV/ c 2 π + mesons, is extended to a three-pion mass of 1.9 GeV/ c . Relative proportions of the contributing partial waves are presented, from threshold, and the A 3 region is discussed in detail. Contrary to results with the (3 π ) − system, a change in phase is noted for the 2 − amplitude decaying to f 0 π + via am S-wave.
FOR A3+ DEFINED AS 2+ S-WAVE WITH 1.5 < M(3PI) < 1.8 GEV).
CONSTRAINT IMPLIES RHO(11) + RHO(1-1) = 0.
CONSTRAINT IMPLIES RHO(11) + RHO(1-1) = 0.
A systematic analysis is presented on the reaction K + p → K ∗0 (890) Δ ++ for nine incident momenta between 4.6–16.0 GeV/ c . Cross sections, differential cross sections and vector meson single density matrix elements are given. As a function of energy, little if any change is observed in either the shapes of the differential cross sections or in the values of the density matrix elements. The data are interpreted in terms of current ideas on t -channel exchange mechanisms.
No description provided.
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In an experiment with the CERN 2 metre DBC the reaction K$^+$d $\to$ K$^0 \pi^+$d is studied at an incident momentum of 4.6 GeV/c. The cross section is found to be (66 ± 10) μb for four-momentum transfer squared from target to recoil deuteron greater than 0.02 GeV 2 , and the reaction is dominated by the production of K$^*+$ (892) via natural parity exchange. Using data for the reactions K$^\pm$d $\to$ K$^{*\pm}$(892)d in the incident momentum range 2–13 GeV/ c the parameters of the effective exchanged trajectory are estimated.
No description provided.
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We have measured the reaction γ p → p π + π − in the DESY 1 m Streamer Chamber. The dominant ϱ o production is analyzed in terms of various models.
No description provided.
FOR ALL EVENTS.
FOR ALL TWO PION EVENTS.
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 observation of 70 000 K 0 p π + events produced with K + incident momenta of 1.21, 1.29, 1.38 and 1.69 GeV/ c allows a detailed description of the production and decay of the Δ(1236) and K ∗ (892) resonances which dominate the K 0 p π + final state. No striking variations with energy are observed. The associated production of Δ and K ∗ near threshold shows striking similarities with the same production at higher energy.
INCLUDING 1 PCT SYSTEMATIC ERROR ON CORRECTIONS.
FIT 'A', ALLOWING FOR DELTA-K* INTERFERENCE (TWO OTHER FITS GIVEN IN PAPER).
S-CHANNEL HELICITY FRAME.
Production and decay properties of the B-meson are studied in the reactions π±p→B±p at 11 GeV/c. Values for mass, width, total and differential cross-sections and spin density matrix elements are given. The spin and parity, and the helicity states in the B→πω decay, are analysed.
BREIT-WIGNER FIT WITH 30 PCT BACKGROUND SUBTRACTED AND CORRECTED FOR UNSEEN OMEGA DECAYS.
FOR <OMEGA PION> EVENTS IN THE B REGION (1.16 TO 1.32 GEV) WITHOUT SUBTRACTING BACKGROUND.
ASSUMING B HAS SPIN-PARITY OF 1+.
A sample of 43000 two-prong events obtained at a momomentum of 11.7 GeV/c is used to determine the cross-sections of the fitted channels, and to study the reaction π+p→π+pπ0. We investigate in particular the quasi-two-body channels π0Δ++ and ρ+p.
No description provided.
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No description provided.
The joint decay density-matrix elements have been measured for the ρ0Δ++ and ωΔ++ channels at 3.7 GeV/c. The data are presented as a function of momentum transfer in both the t-channel and s-channel coordinate systems. The presence of correlated decays is illustrated for both reactions by employing selective cuts on the decay angles of one resonance, and displaying the effects on the decay distribution of the opposing resonance. An amplitude analysis is performed with the data near 0° production angle, where we obtain a helicity decomposition of the scattering amplitude with no experimental ambiguity.
T-CHANNEL COORDINATE SYSTEM (XYZ=TH).
T-CHANNEL COORDINATE SYSTEM (XYZ=TH).
S-CHANNEL COORDINATE SYSTEM (XYZ=SH).
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