Test of quark model predictions in the reactions $\pi^+ p \to \omega \Delta^{++}$ and $\rho^0\Delta^{++}$ at 5 GeV/c

Lyons, L. ; Karshon, U. ; Eisenberg, Y. ; et al.
Nucl.Phys.B 85 (1975) 165-178, 1975.
Inspire Record 1392677 DOI 10.17182/hepdata.32120

The well-known class-A quark-model relations of Białas and Zalewski are parametrised in a particular form, where one can compare the data with the predictions separately for the meson non-flip and flip parts, defined in the transversity frame. A 3-parameter fit to the joint decay angular distribution is performed on the experimental data, and the results are compared with the quark-model predictions for various regions of the four-momentum transfer. The effect of an s -wave state under the ρ 0 is discussed.

1 data table

A THREE PARAMETER FIT IS MADE TO THE JOINT DECAY DISTRIBUTION.


Study of three quasi-two-body channels from pi + p interactions at 3.9 GeV/c

Haber, B. ; Hodous, M.F. ; Hulsizer, R.I. ; et al.
Phys.Rev.D 11 (1975) 495-509, 1975.
Inspire Record 107224 DOI 10.17182/hepdata.24871

The pπ+π0 and pπ+π+π− final states from π+p interactions at 3.9 GeV/c have been analyzed by the prism-plot technique and the following three quasi-two-body channels have been studied in detail: π+p→ρ+p, π+p→π0Δ++, and π+p→ρ0Δ++. Results are presented on cross sections, differential cross sections, and single and joint spin density matrix elements. These are compared with the Dar-Watts-Weisskopf absorption model and Reggeized pion-exchange model predictions. Relations among joint spin density matrix elements for ρ0Δ++ are compared with quark-model predictions.

2 data tables

No description provided.

No description provided.


Study of four-prong events in pi+ p interactions at 3.5 gev/c

Ronat, E.E. ; Eisenberg, Y. ; Lyons, L. ; et al.
Nucl.Phys.B 38 (1972) 20-36, 1972.
Inspire Record 75333 DOI 10.17182/hepdata.32958

The non-strange four-prong events of π + p interactions at 3.5 GeV/ c are studied. Cross sections are calculated for all resonance productions in the channels π + p → p π + π + π − ( σ T = 3.18 ± 0.13 mb) and π + p → p π + π + π − π o ( σ T = 4.03 ± 0.16 mb). The dominant two body reactions Δ ++ ϱ o and Δ ++ ω o are investigated in detail, and production and decay distributions are presented as well as joint decay density matrix elements and joint correlation terms. The Δ ++ ϱ o reaction is compared to predictions of OPE with absorption and the Δ ++ ω o is compared to rho-exchange with sharp cutoff.

7 data tables

FOUR-PRONG, NON-STRANGE CROSS SECTIONS. SYSTEMATIC ERROR INCLUDED.

BREIT-WIGNER RESONANCE FITS, ALLOWING FOR PHASE SPACE AND RELEVANT REFLECTIONS, TO <P PI+ PI+ PI-> FINAL STATE.

BREIT-WIGNER RESONANCE FITS, ALLOWING FOR PHASE SPACE AND RELEVANT REFLECTIONS, TO <P PI+ PI+ PI- PI0> FINAL STATE.

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Rho-omega interference and exchange degeneracy in pi+ p interactions at 5.45 gev/c

Bloodworth, I.J. ; Jackson, W.C. ; Prentice, J.D. ; et al.
Nucl.Phys.B 35 (1971) 133-140, 1971.
Inspire Record 68460 DOI 10.17182/hepdata.33035

The reactions π + p → Δ ++ π + π − and π + p → Δ ++ π + π − π o are used to study ϱ—ω interference at 5.45 GeV/ c . The fitted ϱ mass from a ϱ-ω interference fit is 788 MeV suggesting the possibility of a sum of different interference patterns. Hence the events are weighted by spin density matrix elements which tend to isolate particular exchanges. Results of a fit to these weighted events do not generally agree with the predictions of strong π—B and ϱ—A 2 exchange degeneracy.

1 data table

No description provided.


$\Delta^{++} \rho^0$ and $\Delta^{++} \omega^0$ final states at 5.45 GeV/ c

Bloodworth, I.J. ; Jackson, W.C. ; Prentice, J.D. ; et al.
Nucl.Phys.B 35 (1971) 79-92, 1971.
Inspire Record 68461 DOI 10.17182/hepdata.33069

Results are reported on the Δ ++ ϱ 0 and the Δ ++ ω 0 final states obtained from a 4 event/μb exposure of the Argonne National Laboratory 30 inch hydrogen bubble chamber to a π + beam at 5.45 GeV/ c . Data are presented on cross sections, differential cross sections, spin density matrix elements and differential cross-sections weighted by density matrix elements. Certain features of the data relevant to various Regge models are noted and the data is compared to a π -B exchange degenerate Regge model due to Abrams and Maor.

17 data tables

No description provided.

FROM RESONANCES PLUS BACKGROUND FITS, CORRECTED FOR RESONANCE TAILS AND UNSEEN OMEGA DECAYS.

No description provided.

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Study of pi+ p four prong interactions from 2.95-GeV/c to 4.08-GeV/c

Brown, David ; Gidal, George ; Birge, Robert W. ; et al.
Phys.Rev.D 1 (1970) 3053, 1970.
Inspire Record 74876 DOI 10.17182/hepdata.25065

In a study of the production mechanism of quasi-two-body final states at the five incident π+ momenta 2.95, 3.2, 3.5, 3.75, and 4.08 GeV/c, approximately 40 000 events with four outgoing charged particles were investigated. The cross sections for the processes π+p→N*++ρ, π+p→N*++ω, π+p→N*++η, and π+p→N*++f have been measured as a function of the pion energy. The differential cross sections and the decay density-matrix elements are discussed in terms of one-meson-exchange models [with absorption (OPEA) and with form factor (OPEW)] and Regge models. For the N*++ρ and the N*++ω reactions, the joint-decay matrix elements are calculated. The formation of N*(2850) in the direct channel is also investigated.

30 data tables

No description provided.

No description provided.

No description provided.

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VAN HOVE ANALYSIS OF THE REACTIONS pi- p ---> pi- pi- pi+ p AND pi+ p ---> pi+ pi+ pi- p AT 16-GeV/c

Ballam, Joseph ; Chadwick, G.B. ; Guiragossian, Zaven G.T. ; et al.
Phys.Rev.D 4 (1971) 1946, 1971.
Inspire Record 67149 DOI 10.17182/hepdata.23179

Data from the reactions π−p→π−π−π+p and π+p→π+π+π−p have been obtained at 16 GeV/c in approximately equal samples from the BNL 80-in. hydrogen bubble chamber. We have studied both reactions for resonance production and compared our results with predictions of the one-pion-exchange model (OPEM) calculated by Wolf. The four-body longitudinal phase-space (LPS) plot suggested by Van Hove was used to analyze the data from both reactions. The events were separated according to distinct regions of the LPS plot in order to study the following classes of quasi-two-body final states: (1) diffractively produced three-pion states, (2) diffractively produced ππp states, (3) double-resonance production such as ρ0Δ++, (4) single-resonance production such as π−π−Δ++. The Van Hove analysis provided a much cleaner separation of resonances from background effects than the usual techniques. We observe production of the A1 and A2 mesons as well as the N*(1470) and N*(1700) isobars in the π+π−p system for both reactions. There is strong formation of the doubly resonant states ρ0Δ++ and f0Δ++ and the general features of the nondiffractive events are all in good agreement with one-pion exchange. Detailed comparisons between the data and the OPEM in each LPS plot region show that Van Hove analysis provides a sensitive test for the OPE model.

6 data tables

DEDUCED FROM PRONG CROSS SECTIONS NORMALIZED USING THE DATA OF K. J. FOLEY ET AL., PRL 19, 330 (1967).

No description provided.

No description provided.

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Analysis of the Reaction pi+ p --> p pi+ pi+ pi- at the Momentum of 3.1-GeV/c

Beketov, G.V. ; Ergakov, V.A. ; Zombkovsky, S.M. ; et al.
Yad.Fiz. 28 (1978) 1266-1274, 1978.
Inspire Record 136688 DOI 10.17182/hepdata.18986

None

2 data tables

FROM MAXIMUM LIKELIHOOD FIT TO PARAMETRIZATION OF RESONANCE PRODUCTION CHANNELS.

No description provided.


STUDY OF REACTIONS pi+ p ---> (rho0, omega) DELTA++ (1236) AT 10.3-GeV/c

Beaufays, J. ; Kennedy, C.N. ; Key, A.W. ; et al.
Phys.Rev.D 18 (1978) 27, 1978.
Inspire Record 6322 DOI 10.17182/hepdata.24331

Cross sections, differential cross sections, single and joint spin-density matrix elements are given for the reactions π+p→(ρ0, ω)Δ++ at 10.3 GeV/c. Correlations between the vector-meson and the Δ++ decay angular distributions are observed. A discussion of the results in terms of particle exchange, SU(3) symmetry, quark additivity, and the equal-phase hypothesis is presented. The amplitudes for the process π+p→ρ0Δ++ are extracted by a model-dependent analysis and compared with current theoretical predictions.

9 data tables

P-WAVE BREIT-WIGNER RESONANCES PLUS BACKGROUND USED WITH SLICE TECHNIQUE.

FROM RESONANCE OVERLAP REGION WITH BACKGROUND SUBTRACTED AND NORMALIZED TO TOTAL CROSS SECTION.

FROM RESONANCE OVERLAP REGION WITH BACKGROUND SUBTRACTED AND NORMALIZED TO TOTAL CROSS SECTION.

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Amplitude Analysis of the Reaction pi+ p --> rho0 Delta++ at 3.75-GeV/c

Gelfand, N. ; Dagan, S. ; Lissauer, D. ; et al.
Nucl.Phys.B 138 (1978) 365-386, 1978.
Inspire Record 135354 DOI 10.17182/hepdata.35047

The joint decay distribution statistical tensors for the reaction π + p→ ϱ 0 Δ ++ have been measured as a function of t at 3.75 GeV/ c . From this data the amplitude components of the reaction were extracted using both t -independent and t -independent methods. The magnitudes of the amplitudes obtained from both methods are found to agree and appear to be insensitive to the fitting methods. The phases are not well determined in the t -independent method. A comparison is made with a similar analysis done at 7.1 GeV/c.

3 data tables

UNITS OF D(SIG)/DT ASSUMED TO BE MUB/GEV**2.

No description provided.

No description provided.


Partial, Total, and Resonance Production Cross-Sections for the Reactions pi+ p --> Four Prong Final States at 10.3-GeV/c

Kennedy, C.N. ; Zemany, P.D. ; Beaufays, J. ; et al.
Phys.Rev.D 17 (1978) 2888-2900, 1978.
Inspire Record 135353 DOI 10.17182/hepdata.24403

The major production channels of four-prong final states resulting from π+p interactions at a center-of-mass energy of 4.5 GeV are studied. In addition to total production cross sections, comprehensive listings of partial and resonance production cross sections are also given for each final state of interest. All final states, including nπ+π+π+π−, are found to exhibit copious resonance production.

2 data tables

PARTIAL CROSS SECTIONS FROM PI+ P --> PI+ P PI+ PI-.

PARTIAL CROSS SECTIONS FROM PI+ P --> PI+ P PI+ PI- PI0.


Rho0 delta++ and omega delta++ joint decay correlations at 3.7 gev/c

Barnham, K.W.J. ; Abrams, G.S. ; Butler, W.R. ; et al.
Phys.Rev.D 7 (1973) 1384-1394, 1973.
Inspire Record 82336 DOI 10.17182/hepdata.22157

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.

4 data tables

T-CHANNEL COORDINATE SYSTEM (XYZ=TH).

T-CHANNEL COORDINATE SYSTEM (XYZ=TH).

S-CHANNEL COORDINATE SYSTEM (XYZ=SH).

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A Study of the Reactions pi+ p --> (rho0, omega) Delta++ at 13-GeV/c

Gaidos, J.A. ; Hirata, A.A. ; DeBonte, R.J. ; et al.
Nucl.Phys.B 72 (1974) 253-282, 1974.
Inspire Record 763 DOI 10.17182/hepdata.32316

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.

10 data tables

BREIT-WIGNER FITS WHICH CORRECT FOR RESONANCE TAILS AND BACKGROUNDS.

No description provided.

JACKSON FRAME DENSITY MATRIX ELEMENTS.

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Cross sections for resonance production in the reaction pi+- p ---> p pi+- pi+ pi- at 16-GeV/c, as obtained by a maximum likelihood fit

The Aachen-Berlin-Bonn-CERN-Heidelberg collaboration Honecker, R. ; Rumpf, K. ; Tsanos, N. ; et al.
Nucl.Phys.B 50 (1972) 157-165, 1972.
Inspire Record 84326 DOI 10.17182/hepdata.32751

Cross sections for resonance production in the reactions π ± p → p π ± π + π − at 16 GeV/ c are determined by a maximum likelihood fit, making use of the measurements of all individual events. The reactions are described by a simple parametrization based on an incoherent superposition of amplitudes for quasi two-body and quasi three-body processes and a non-resonant backgroud. In this way the reflections are accounted for in a consistent way. Thus cross sections are obtained for Δ ++ , Δ 0 , ρ 0 and f 0 production which do not suffer from the uncertainties of background subtraction typical of the usual technique of fitting individual mass distributions.

2 data tables

TWO PARTICLE RESONANCE CROSS SECTIONS.

CHANNEL FRACTIONS FROM THE FITS. THE AUTHORS WARN AGAINST DERIVING CROSS SECTIONS FOR THREE-PARTICLE RESONANCES.


Amplitude Analyses of the Reactions pi+ p --> (rho0, omega) Delta++ at 7.1-GeV/c

Owens, J.F. ; Eisner, R.L. ; Chung, S.U. ; et al.
Nucl.Phys.B 112 (1976) 514-544, 1976.
Inspire Record 3423 DOI 10.17182/hepdata.35710

New data are presented, in the form of statistical tensors, for the reactions π + p → ( ϱ 0 , ω ) Δ ++ at 7.1 GeV/ c . Using these data, two types of model-dependent amplitude analyses have been performed. Both analyses, though based on different sets of assumptions, yield results which are in agreement with each other. The structure observed in the magnitudes and phases of the extracted amplitudes is consistent with that expected on the basis of currently accepted phenomenological ideas.

2 data tables

No description provided.

No description provided.


PRISM Plot Analysis of the Reaction pi+ p --> p pi+ pi+ pi- at 16-GeV/c

The AACHEN-BERLIN-BONN-CERN-CRACOW-HEIDELBERG-WARSAW collaboration Deutschmann, M. ; Kirk, H. ; Sixel, P. ; et al.
Nucl.Phys.B 99 (1975) 397-419, 1975.
Inspire Record 104134 DOI 10.17182/hepdata.35967

We have analysed the reaction π + p → pπ + π + π − at 16 GeV/c by means of the prism plot analysis (PPA) as proposed by Pless et al. We have separated ten reaction channels contributing to the final state pπ + π + π − and present the results in terms of partial and differential cross sections, invariant mass and decay angular distributions. We show that the PPA is a self-controlling method which is demonstrated by the emergence of a broad (3π) + enhancement around 1800 MeV decaying into ρ 0 π + .

1 data table

PARTIAL CROSS SECTIONS FOR THE (P PI+ PI+ PI-) FINAL STATE.


Production of the Delta (1950) by One Pion Exchange in pi+ p Interactions at 13-GeV/c

Gaidos, J.A. ; Miller, David Harry ;
Phys.Rev.D 12 (1975) 2565, 1975.
Inspire Record 2181 DOI 10.17182/hepdata.24834

We have observed the production of high-mass I=32 baryon resonances in π+p interactions at 13 GeV/c. The most prominent of these is found to be the F37 Δ(1950). It is produced by one-pion exchange and the data are well described by on-shell π+p phase shifts. Decays into pπ+ and pπ+π0 are observed and the Δ(1950) is found to have a mass 1.880 ± 0.010 GeV and width of 0.180 ± 0.030 GeV with a production cross section of 43 ± 4 μb.

1 data table

RESONANCE BACKGROUNDS SUBTRACTED.


Study of Vector Meson Baryon Resonance Production in pi+ p Interactions at 7.1-GeV/c

Chung, S.U. ; Protopopescu, S.D. ; Eisner, R.L. ; et al.
Phys.Rev.D 12 (1975) 693, 1975.
Inspire Record 99147 DOI 10.17182/hepdata.48154

From a large-statistics π+p experiment at 7.1 GeV/c, data are presented on the reactions π+p→ρ0Δ++(1238) and π+p→ωΔ++(1238). Cross sections, differential cross sections, and vector-meson single-density-matrix elements are presented and a general comparison of the production properties of the two reactions is given. In addition to (ρ,ω)Δ++(1238) production there is also strong evidence for production of a π+p enhancement with mass ∼ 1880 MeV, Γ∼200 MeV, and J≥72 produced in association with the ρ and ω resonances. Detailed properties of this structure are presented and its production mechanism is compared with that of the corresponding Δ(1238) reactions. This state is also observed in the reaction K+p→K*0(890)Δ++(1880) at 12.0 GeV/c, for which data are also presented.

15 data tables

STATISTICAL ERRORS ONLY.

No description provided.

JACKSON FRAME.

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Study of the Reaction pi+ p --> rho0 Delta++ (1236) at 16-GeV/c

The Aachen-Berlin-Bonn-CERN-Cracow-Heidelberg collaboration Honecker, R. ; Lauscher, P. ; Laven, H. ; et al.
Nucl.Phys.B 106 (1976) 365-384, 1976.
Inspire Record 108897 DOI 10.17182/hepdata.35864

The reaction π + p → ϱ 0 Δ ++ (1236) at 16 GeV/ c has been studied. Cross section, differential cross section, single and joint spin-density matrix elements are given. Correlations between the ϱ 0 and Δ ++ (1236) decay distributions are observed. Unnatural spin-parity exchanges, mainly observed at small t ' values, dominate the ϱ 0 Δ ++ (1236) production. The natural exchange contributions are only (7 ± 2)% and become as important as the unnatural exchanges beyond t ' = 0.3 GeV 2 . Contributions to Δ ++ (1236) helicity 3 2 states do not exceed 20% of the total ϱ 0 Δ ++ (1236) cross section and are mainly due to unnatural exchanges.

6 data tables

'SLICE METHOD' USED TO HANDLE RESONANCE TAILS AND BACKGROUND.

FROM EVENTS WITHIN MASS-CUTS FOR RESONANCES AND NORMALIZED TO TOTAL CROSS SECTION.

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