In this paper a comparison of the general features of the reactions K ± p→Q ± p (1) at incident momentum 8.25 GeV/ c is presented. The relevant data derive from events yielding four-constraint fits to the reactions K ± p→K ± π + π − p in exposures of the CERN 2m HBC to RF-separated K + and K − beams. The (K ππ ) effective mass distributions, production angular distributions in the Q region (1.2⩽ M (K ππ )⩽1.5 GeV) and corresponding decay angular distributions are exhibited, and background effects due to N ∗ and Δ production are systematically studied. In particular, it is found that the distributions d σ /d t ′ and d σ /d t for reactions (1) are adequately described by exponential functions over the interval 0.05–0.35 GeV 2 , and exhibit a cross-over effect for momentum transfer squared −0.1 GeV 2 . For both reactions a flattening of d σ /d t ′ for t ′ < 0.05 GeV 2 is observed. By studying the Chew-Low plots and the effects of the different cuts it was found that this flattening cannot be attributed to amplitudes with net s -channel helicity flip different from zero, at least at these energies.
ABOUT 7 PCT RELATIVE NORMALIZATION UNCERTAINTY FOR K+ AND K- SAMPLES.
FITS TO D(SIG)/DT AND D(SIG)/DTP FOR Q+ AND Q- PRODUCTION TO DETERMINE CROSS-OVER POSITIONS. DATA HAVE MASS CUTS TO SELECT K*0 AND REMOVE DEL++ AND DEL0. MIN IS THE MINIMUM VALUE OF -T FOR THE RELEVANT (K PI PI) MASS.
Results are presented from an experiment designed to make the first systematic study of the depolarization parameter in elastic proton-proton scattering at high energies. Measurements were made at 3.0 and 6.0 GeV/c at |t| values extending to 1.7 (GeV/c)2 at the higher momentum. A high-intensity unpolarized proton beam was incident on a polarized proton target and the polarization of the elastically scattered recoil protons was determined with a carbon analyzer. The results are discussed in the framework of optical and exchange models.
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We present data on inclusive and semi-inclusive ϱ 0 production in 147 GeV/ c π − p interactions. We find a total cross section of 7.3 ± 1.3 mb. Most of this cross section is found in the lower topology events (⩽ 10 prongs), and in the central and forward rapidity regions. The P T 2 dependence of ϱ 0 production, 〈: n > ϱ 0 per event, and the ϱ 0 / π + ratios are also discussed.
No description provided.
We report on partial results of the analysis of a p̄p backward elastic scattering experiment, between 175 and 750 MeV/ c . Various evidences are given of the resonant nature of a backward peak at the S-meson mass. Analysis leads to J PC =4 ++ , firmly connected to other experimental data with I G =1 − . All results agree for an assignment to the A 2 trajectory.
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Results are presented for the reactions (1) π+n→pπ+π−, (2) π+n→pπ+π−π0, at an incident pion beam momentum of 11.7 GeV/c. Both reactions show considerable resonance production. Reaction (1) is dominated by ρ0 and f0 production and there is evidence for the variation of the ρ00 width with momentum transfer. Decay angular distributions are presented for the dipion system observed in reaction (1). Reaction (2) shows the production of both dipion and tripion resonances and there is evidence for the associated production of\(\mathcal{N}\)-resonances with the dipion resonances.
No description provided.
DN/DT PLOTTED. ALL RESONANCES ARE DEFINED JUST BY MASS CUTS.
RHO0 MASS REGION OF DIPION SYSTEM. NUMERICAL VALUES TAKEN FROM TABLE 6.1 OF THE THESIS BY D. KEMP (DURHAM 1974).
Cross sections are given for the various exclusive reactions K − p→ Λ 0 + n pions, as well as for quasi two-body final states involving ϱ 0 , ω 0 and Y 1 ∗ (1385) resonance production. The general features of Λ 0 production are presented as a function of the pion multiplicity n . Production of Y 1 ∗+ (1385) is clearly observed at all multiplicities while the Y 1 ∗− (1385) signals grow with the multiplicity, as expected in a non-exotic exchange picture. The polarisation of the Λ 0 is consistent with zero everywhere, except when it is a decay product of Y 1 ∗ (1385), when non-zero values are found for odd values of n . The reactions Λ 0 + 2π and Λ 0 + 3π are analysed in terms of the Plahte-Roberts model and good overall agreement is obtained for the various effective mass distributions and the p L ∗ , p T and cos θ distributions for the individual particles.
No description provided.
An accurate measurement of d σ d Ω (π − p → η n ) at 1531 MeV total energy (expanded) up to l = 4 Legendre polynomials) requires reconsideration of previous angular distribution fits which were expanded only up to l = 2 and of subsequent partial-wave analysis. An energy-dependent partial-wave analysis has been performed here for p η ∗ up to 450 MeV/ c . In addition to the well-known S 11 (1520 MeV) resonance, either the P 11 (1532 MeV) or the P 13 (1530 MeV) resonance is found to be strongly coupled to the η-n channel. In both cases, the P 11 (1729 MeV) resonance is needed as is the weakly coupled D 13 (1525 MeV) resonance. The decay states in the ηn channelare compared to the SU(3) and SU(6) W predictions.
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The modulus and the phase of the K L o −K S o regeneration amplitude on carbon have been measured. In a momentum range of 16–40 GeV/ c the phase is constant within experimental error bars and coincides with the regeneration phase on hydrogen. Both the modulus and the phase of the regeneration amplitude on carbon are in agreement with optical model predictions.
ASSUMING A CONSTANT PHASE INDEPENDENT OF MOMENTUM, THE CARBON REGENERATION AMPLITUDE HAS A PHASE OF -130 +- 17 DEG.
At the 500 MeV electron synchrotron in Bonn differential cross sections of the reaction γ + d → π 0 + d were measured in forward pion c.m. angles and photon energies between 340 and 420 MeV.
No description provided.
The angular distributions of the reactions K - p → K - p and K - p → K K 0 n have been measured at 23 incident K - momenta between 1.136 and 1.798 ifGeV/c using the bubble chamber technique. These data, together with other published data on the same reactions, including K - p polarisations, K̄N total cross sections, and measurements of Re ƒ(0)/ Im ƒ(0) , have been analysed in terms of partial-wave amplitudes. Resonance behaviour is confirmed for the P 03 partial wave at 1890 MeV. The resonance parameters of the F 15 (1915), F 17 (2030) and G 07 (2100) have been redetermined. No evidence has been found for new resonances coupling significantly to K K N in the energy region explored.
No description provided.
No description provided.
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