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Two-body strange-particle final states in pi- p interactions at 4.5 and 6 gev/c

Crennell, D.J. ; Gordon, H.A. ; Lai, Kwan-Wu ; et al.

Phys.Rev.D 6 (1972) 1220-1254, 1972.

Inspire Record 73936 DOI 10.17182/hepdata.3601

Results on the following π−p reactions involving a hyperon are studied at 4.5 and 6.0 GeV/c from a high-statistics bubble-chamber experiment. (1) π−p→(Λ, Σ0)K0: Differential cross sections and hyperon polarizations are presented. Comparison with the line-reversed reactions K¯N→(Λ, Σ0)π indicates the failure of the predictions of K*(890) and K*(1420) exchange degeneracy. Effective trajectories for these two reactions are compared. Shrinkage is observed in K¯N→Λπ and not in π−p→ΛK0. (2) π−p→(Λ, Σ0)K*(890)0: Differential cross sections, hyperon polarizations, and K*(890)0 density-matrix elements are determined. ΛK*(890)0 decay correlations are found to impose strong constraints on the scattering amplitudes. The data indicate that both natural- and unnatural-parity exchanges contribute large, but opposite, Λ polarizations. This behavior cannot be explained by a simple exchange model utilizing K and the exchange-degenerate K*(890) and K*(1420) only. Additional trajectories or absorption effects are required to obtain the observed Λ-polarization effects. Comparison of ΛK*(890)0 and Σ0K*(890)0 indicates the greater importance of unnatural-parity exchange in the former reaction. We observe no evidence for deviations from isospin predictions in ΛK*(890)0 production where K*(890)0→K+π− and KS0π0. (3) π−p→ΛK*(1420)0 and ΛK*(1300)0: K*(1420)0 density-matrix elements satisfying positivity constraints are determined allowing for s-wave interference effects. Evidence of the existence of a narrow K*(1300)0→Kππ with a dominant K+ρ− decay mode is observed in the 4.5- and 6-GeV/c data. (4) Σ(1385), Λ(1405), Λ(1520) production: Differential cross sections for the quasi-two-body reactions π−p→Y0K0, where Y0 is Λ(1405), Λ(1520), or Σ(1385)0, are presented and found to have a very similar flat slope in the forward direction. Data for forward K+ scattering in the reaction π−p→Σ(1385)−K+ are presented and discussed. It is argued that this forward peak cannot be explained by kinematic reflection or an s-channel effect and therefore must be due to either two-particle exchange or a single exotic exchange in the t channel.

39 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

FIT FOR FORWARD CROSS SECTION AND SLOPE.

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p p Interactions at 303-GeV/c: Multiplicity and Total Cross-Section.

Dao, F.T. ; Gordon, D. ; Lach, J. ; et al.

Phys.Rev.Lett. 29 (1972) 1627-1630, 1972.

Inspire Record 73776 DOI 10.17182/hepdata.21429

In an exposure of the 30-in. hydrogen bubble chamber to a 303−GeVc proton beam, 2245 interactions have been observed. The measured total cross section is 39.0±1.0 mb and the average charged particle multiplicity 〈nch〉=8.86±0.16.

1 data table

Table 1

TOPOLOGICAL CROSS SECTIONS.

Study of the reaction k+ p ---> k*0(890) delta++ from 4.6-16.0 gev/c

Ciapetti, G. ; Eisner, R.L. ; Irving, A.C. ; et al.

Nucl.Phys.B 64 (1973) 58-108, 1973.

Inspire Record 94946 DOI 10.17182/hepdata.6741

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.

20 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Topological and Leading Particle Cross-Sections for 147-GeV/c $\pi^- p$ Interactions.

Fong, D.G. ; Heller, M. ; Shapiro, A.M. ; et al.

Phys.Lett.B 53 (1974) 290-296, 1974.

Inspire Record 93415 DOI 10.17182/hepdata.27916

Results are reported based on a study of π − p interactions at 147 GeV/ c in the FERMILAB 30-inch Proportional Wire Hybrid Bubble Chamber System. We have measured the topological cross sections and separated two-prong elastic and inelastic channels. In addition, we have extracted leading particle cross sections using the increased momentum resolution of the downstream proportional wire chambers. We have compared our results with experiments and predictions of a simple fragmentation hyphothesis.

1 data table

Table 1

No description provided.

Low Momentum K+ d Scattering

Glasser, R.G. ; Snow, G.A. ; Trevvett, D. ; et al.

Phys.Rev.D 15 (1977) 1200-1214, 1977.

Inspire Record 124116 DOI 10.17182/hepdata.24651

The differential cross sections for K+d coherent, breakup, and charge-exchange scattering have been measured at several momenta in the interval 250-600 MeV/c. The data have been fitted using a partial-wave analysis. Assuming an s-wave description of I=1 scattering and using data from the coherent and charge-exchange channels, a description of I=0 K+−N scattering by a combination of s and p waves in a simple single-scattering impulse model has been attempted. The phase shifts obtained are unique up to the Fermi-Yang ambiguity, which can be removed by using existing polarization results at 600 MeV/c.

8 data tables

Table 1

COHERENT SCATTERING DIFFERENTIAL CROSS SECTION IN THE LABORATORY FRAME.

Table 2

COHERENT SCATTERING DIFFERENTIAL CROSS SECTION IN THE LABORATORY FRAME.

Table 3

COHERENT SCATTERING DIFFERENTIAL CROSS SECTION IN THE LABORATORY FRAME.

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Inclusive phi Production in pi- p Interactions at 16-GeV/c

The Bari-Bonn-CERN-Daresbury-Glasgow-Liverpool-Milan-Vienna collaboration Ghidini, B. ; Navach, F. ; Palano, A. ; et al.

Phys.Lett.B 68 (1977) 186, 1977.

Inspire Record 119248 DOI 10.17182/hepdata.48929

Inclusive φ production is studied in π − p collisions at 16 GeV/ c . The φ cross section for Feynman variable x φ > 0.2 is found to be (15.5 ± 3.6) μb. This leads to an extrapolated cross section of (29.9 ± 7.0) μb for x φ > 0.0. Fitting the momentum transfer squared distribution of the φ to the form e −bp 2 T gives an average slope of b = (2.4 ± 0.3) (GeV/ c −2 for x φ > 0.5.

4 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

DATA OBTAINED FROM FIGURE BY A.A. LEBEDEV.

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Production and Decay of a High Mass I = 3/2 Baryon Enhancement in 10.3-GeV/c pi+ p Interactions

Zemany, P.D. ; Beaufays, J. ; Goddard, M.C. ; et al.

Nucl.Phys.B 137 (1978) 365-376, 1978.

Inspire Record 5279 DOI 10.17182/hepdata.35058

A high-mass Δ resonance is observed in several final states from π + p interactions at 10.3 GeV/ c . We obtain fitted mass and width values for this structure of 1871 ± 22 MeV and 205 ± 43 MeV, respectively. The branching ratios for decays to π + p, p π + π 0 , n π + π + and Σ + K + are found to be 0.48 ± 0.15, 0.26 ± 0.07, 0.24 ± 0.07 and 0.03 ± 0.01, respectively. The Δϱ, Δω differential cross sections and the ϱ 0 density matrix elements are examined.

3 data tables

Table 1

DEL(1950B) (OR DEL(1880B)) FITTED WITH BRIET-WIGNER RESONANCE AND POLYNOMIAL BACKGROUND.

Table 2

No description provided.

Table 3

No description provided.

Strange Particle Cross-Sections from pi+ p Interactions at 10.3-GeV/c

Goddard, M.C. ; Gilbert, D. ; Key, A.W. ; et al.

Phys.Rev.D 16 (1977) 7, 1977.

Inspire Record 5358 DOI 10.17182/hepdata.24450

Cross sections are presented for production of final states with two strange particles from π+p interactions at 10.3 GeV/c in a 31.1-event/μb bubble-chamber experiment.

2 data tables

Table 1

No description provided.

Table 2

No description provided.