Measurement of Differential Cross-Section and Polarization in the Backward Peak of the Reactions pi- p --> Lambda K0 and pi- p --> Lambda K* (890) at 8-GeV/c

Brundiers, H. ; Hartung, R. ; Runge, K. ; et al.
Nucl.Phys.B 119 (1977) 349-361, 1977.
Inspire Record 123952 DOI 10.17182/hepdata.35527

Differential cross sections and polarizations have been measured for the backward peaks in the reactions π − p →Λ K 0 and π − p →Λ K ∗ (890) at 8 GeV/c. The experiment was performed with a liquid hydrogen target at the ω spectrometer. The cross sections for u′>−2 ( GeV /c) 2 are 0.27 ± 0.03 μ b for π − p →Λ+ K 0 and 0.55±0.07 μ b for π − p →Λ K ∗0 . Large positive Λ polarization was observed in both reactions for u ′>−0.5 (GeV/ c ) 2 . The dominant production mechanism was found to be unnatural baryon exchange.

3 data tables

Axis error includes +- 0.0/0.0 contribution (?////).

Axis error includes +- 0.0/0.0 contribution (?////).

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Cross-Sections and Polarizations in the Reactions pi- p --> Lambda K0 and pi- p --> Lambda K* (890) Near the Backward Direction, from 3-GeV/c to 6-GeV/c

Ward, C.E.W. ; Ambats, I. ; Lesnik, A. ; et al.
Phys.Rev.D 16 (1977) 2041, 1977.
Inspire Record 4930 DOI 10.17182/hepdata.24506

We have measured the differential cross sections and Λ polarizations in the reactions π−p→ΛK0 and π−p→ΛK*0 (890) near the backward direction, at 3, 4, 5, and 6 GeV/c. Data equal to several times the world's total sample above 2 GeV/c were recorded. Both reactions are characterized by cross sections falling rapidly with beam momentum, and by large positive Λ polarizations for u′ between 0.0 and 0.6 GeV2. Analysis of π−p→ΛK0 yields an effective Regge trajectory consistent with antishrinkage of the backward peak. Separation into amplitudes of definite-parity-naturality exchange shows the reaction to be dominated by unnatural-parity exchange. The energy behavior of this exchange is, however, not consistent with a single linear baryon Regge trajectory or exchange-degenerate pair of trajectories. An apparent normalization discrepancy between data on π−p→ΛK0 of a CERN-ETH group and other high-statistics data including that of this experiment is discussed.

10 data tables

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Measurement of the Backward Peaks in the Reactions pi- p --> K0 Lambda and pi- p --> K*0 (890) Lambda

Foley, K.J. ; Love, W.A. ; Ozaki, S. ; et al.
Phys.Rev.D 10 (1974) 2763, 1974.
Inspire Record 1420 DOI 10.17182/hepdata.24944

We present the differential cross sections near u=0 for the reactions π−p→K0Λ and π−p→K*0(890)Λ at incident pion momenta of 8 and 10.7 GeV/c. The differential cross section for the first reaction follows the exponential dependence on u previously observed, while the second shows a dip in the backward direction.

3 data tables

Axis error includes +- 25/25 contribution.

Axis error includes +- 25/25 contribution.

Axis error includes +- 25/25 contribution.


A STUDY OF THE REACTIONS pi- p ---> K* LAMBDA, K* SIGMA AND K* Y1* (1385) AT 3.93-GeV/c

Yaffe, D. ; Abramovich, M. ; Chaloupka, V. ; et al.
Nucl.Phys.B 75 (1974) 365-387, 1974.
Inspire Record 80700 DOI 10.17182/hepdata.32197

We have investigated the final states K ∗0 (890)Σ, K ∗0 (890)Σ 0 and K ∗0 (890) Y 1 ∗0 (1385) produced in π − p interactions at 3.93 GeV/ c . We present the differential cross sections and spin density matrix elements for the resonances as functions of momentum transfer, as well as the gL and Σ 0 polarizations. The Σ 0 polarization is found to be positive and maximal. An amplitude analysis is performed for the K ∗ Λ and K ∗ Σ 0 reactions, and it is found that one natural parity transversity amplitude is dominant for the latter.

14 data tables

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Amplitude analysis from decay correlations - application to pi- p ---> k*(0) lambda at 3.9 gev/c

Abramovich, M. ; Irving, A.C. ; Martin, Alan D. ; et al.
Phys.Lett.B 39 (1972) 353-357, 1972.
Inspire Record 75784 DOI 10.17182/hepdata.28306

Decay correlation data for π − p → K ∗ Λ at 3.9 GeV /c are analyzed to determine the amplitude structure. We emphasize combinations of observables invariant under rotations between s and t channel frames.

1 data table

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Study of the k*0 lambda and k*0 sigma0 final states from pi- p interactions at 3.9 gev/c

Abramovich, M. ; Chaloupka, V. ; Chung, S.U. ; et al.
Nucl.Phys.B 39 (1972) 189-200, 1972.
Inspire Record 75244 DOI 10.17182/hepdata.32953

A study of π − p → K ∗ Λ and π − p → K ∗ Σ° at 3.9 GeV /c indicates that the main features of both reactions can be interpreted in terms of simple exchange processes, the first involving both natural and unnatural exchange, the second showing evidence for natural parity exchange only.

1 data table

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K*0 (890) POLARIZATION MEASUREMENTS IN THE HYPERCHARGE EXCHANGE REACTION PI- P ---> K*0 (890) LAMBDA0 / SIGMA0 AT 10-GEV/C

The BARI-BONN-CERN-DARESBURY-GLASGOW-LIVERPOOL-MILAN-VIENNA collaboration Evangelista, C. ; Ghidini, B. ; Palano, A. ; et al.
Nucl.Phys.B 165 (1980) 383-394, 1980.
Inspire Record 157497 DOI 10.17182/hepdata.34585

K ∗0 (890) production in the hyperchange exchange reaction π − p → K ∗0 (890) Λ 0 Σ 0 at 10 GeV/ c (28 448 events) is discussed. An amplitude analysis in the t ′ range up to 1 GeV 2 shows that the production mechanism is dominated by natural parity exchange (∼84%). Comparisons are made with predictions from a Regge model and a quark model.

2 data tables

DENSITY MATRIX ELEMENTS IN THE GOTTFRIED-JACKSON SYSTEM ALLOWING FOR COHERENT S-WAVE BACKGROUND TO P-WAVE BREIT-WIGNER K*(892)0 RESONANCE.

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Backward $K^{*0}$ Production in $\pi^- p \to \Lambda^0 K^+ \pi^-$ Reaction at 9-{GeV}/$c$ and 12-{GeV}/$c$

Ferrer, A. ; Treille, D. ; Rivet, P. ; et al.
Nucl.Phys.B 178 (1981) 373-391, 1981.
Inspire Record 153782 DOI 10.17182/hepdata.34397

We have analysed about 85 000 fast Λ 0 events, obtained in a fast proton triggered experiment performed at the CERN-Ω spectrometer at 9 and 12 GeV/ c incident π − beam. Nearly 2500 Λ 0 K + π − events have been isolated. We find strong production of quasi-two-body processes Λ 0 K ∗0 and ∑ ∗− K + consistent with u -channel hyperon exchange. Results on Λ 0 polarization, K ∗0 decay parameters and differential cross sections are given for Λ 0 K ∗0 (892) and Λ 0 K ∗0 (1430) final states. A comparison is made with the associated backward Λ 0 (1520) K ∗0 production seen in the four-prong reaction π − p→pK − K + π − obtained in the same experiment.

8 data tables

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EXPONENTIAL FIT TO DN/DU.

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Study of Hypercharge Exchange Reactions of the Type 0- 1/2+ $\to$ 2+ 1/2+ at 4-{GeV}/$c$

The CERN-College de France-Madrid-Stockholm collaboration Aguilar-Benitez, M. ; Albajar, M.C. ; Ferrando, A. ; et al.
Z.Phys.C 8 (1981) 313, 1981.
Inspire Record 156685 DOI 10.17182/hepdata.13530

Results are presented for the quasi two-body hypercharge exchange reactions of the type 0−1/2+→2+1/2+:$$\begin{gathered}

12 data tables

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Strange-particle production in pi- p collisions at 11.2 gev/c leading to two charged final particles

Dameri, M. ; Tomasini, G. ; Trevisan, U. ; et al.
Nuovo Cim.A 9 (1972) 1-27, 1972.
Inspire Record 78421 DOI 10.17182/hepdata.37457

In this paper we present the results of an analysis of strange-particle production in π−p collisions leading to two charged final particles and at least one strange neutral decay. The sample consists

1 data table

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