Date

p-p Interactions at 2 Bev. 2. Multiple-Pion Production

Pickup, E. ; Robinson, D.K. ; Salant, E.O. ;
Phys.Rev. 125 (1962) 2091-2101, 1962.
Inspire Record 47226 DOI 10.17182/hepdata.26793

Analyses have been made for 871 four-prong events and 463 two-prong events corresponding to multiple pion production, resulting from p−p interactions at 2 Bev in the BNL 20-in. hydrogen bubble chamber. Cross sections have been obtained for all the observable double and triple pion production processes; the branching ratios predicted by the extended isobar model are shown to be in fair agreement with the data, but there are significant differences. The c.m. momentum distributions are also in fair agreement with the predictions of the model, although there are ambiguities in the interpretation. The pion-nucleon Q values give clear evidence for the importance of the (32, 32) resonant state in multiple pion production, but consideration of this state alone does not provide an explanation of the features of double pion production. Some contribution from another state, possibly the I=12 nucleon isobar, is necessary. In double production, the c.m. angular distributions of the nucleons show backward-forward peaking suggestive of a one-pion exchange process. The angular distributions of the nucleons from triple production are almost isotropic.

1 data table

No description provided.


p-p Interactions at 2 Bev. 1. Single-Pion Production

Fickinger, W.J. ; Pickup, E. ; Robinson, D.K. ; et al.
Phys.Rev. 125 (1962) 2082-2090, 1962.
Inspire Record 46669 DOI 10.17182/hepdata.26851

3600 two-pronged events, obtained in p−p interactions at 2 Bev in the BNL 20-in. hydrogen bubble chamber, have been analyzed. Cross sections have been measured for elastic scattering, for the two modes of single-pion production, p+p→p+n+π+, p+p→p+p+π0, and for strange-particle production. The branching ratio for the two one-pion production reactions is σ(pnπ+)σ(ppπ0)=4.17±0.25. Momentum distributions and Q values indicate that single-pion production proceeds almost entirely through the (32, 32) resonant state. The data have been considered in terms of the extended isobar model and also a one-pion exchange model for production. The branching ratio and momentum distributions can be explained by including a small effect from the I=12 resonant state in addition to the dominant I=32 resonance. The c.m. angular distribution of the nucleons in single-pion production shows very marked backward-forward peaking indicating a one-pion exchange mechanism. Absolute differential cross sections as a function of laboratory kinetic energy have been calculated from Selleri's equation for the pnπ+ reaction. There is good agreement with the data for low four-momentum transfers [q2<0.15(Bev/c)2], but for higher momentum transfers the theoretical cross sections are larger than the experimental cross sections.

1 data table

No description provided.


Single and Multiple Pion Production in pi+n and pi-p Interactions at 1.7 GeV/c

Bacon, T.C. ; Fickinger, W.J. ; Hill, D.G. ; et al.
Phys.Rev. 157 (1967) 1263-1278, 1967.
Inspire Record 52416 DOI 10.17182/hepdata.26582

Meson production in π−p and π+n interactions at 1.7 GeV/c has been studied in two bubble-chamber exposures. Combined results are presented with emphasis on single-pion production (4300 events) which is dominated by the formation of the ρ0 meson in peripheral interactions, and on double-pion production (1100 events) which shows strong formation of the ω meson. These data are compared with the predictions of particle-exchange models, including absorption, and the effects of competing channels are discussed. Evidence for a two-pion decay mode of the ω is examined quantitatively. Processes with higher meson multiplicities are described.

1 data table

No description provided.


K+ n charge exchange at 3.8 gev/c

Moninger, W. ; Eisenstein, Bob I. ; Kim, J. ; et al.
Phys.Rev.D 8 (1973) 38-44, 1973.
Inspire Record 81978 DOI 10.17182/hepdata.22019

We have found 431 events of the reaction K+d→K0pps at 3.8−GeVc K+ beam momentum in a 295 000-frame exposure of the Argonne National Laboratory 30-in. deuterium-filled bubble chamber. The event sample consists of one- and two-prong events with a visible K0 decaying to π+π− The total and differential cross sections are found after correction for unseen K0's and for efficiencies in the scanning-measuring-fitting chain. Comparisons of the data are made to an SU(3) sum rule, a Regge model, and data for K−p→K¯0n.

2 data tables

No description provided.

GLAUBER SCREENING AND PAULI EXCLUSION PRINCIPLE CORRECTIONS ARE REQUIRED TO YIELD THE K+ N CHARGE EXCHANGE CROSS SECTION. THE GLAUBER CORRECTION IMPLIES AN INCREASE IN THE CROSS SECTIONS BY THE FACTOR 1.016. THE PAULI CORRECTION IS SLIGHT EXCEPT AT LOW -T (<0.2 GEV**2) WHERE IT IS LARGE AND UNCERTAIN.


Study of the reaction pi+ n ---> omega p at 6.0 gev/c

Anderson, J.C. ; Engler, A. ; Kraemer, R.W. ; et al.
Phys.Lett.B 45 (1973) 165-168, 1973.
Inspire Record 84780 DOI 10.17182/hepdata.28073

An analysis of the reaction π + n→ ω p in a 6.0 GeV/ c bubble chamber experiment is presented. The production differential cross section and spin density matrix elements are compared with Regge exchange models.

3 data tables

CORRECTED FOR BACKGROUND.

HELICITY FRAME. T-DEPENDENT BACKGROUND SUBTRACTED.

TRANSVERSITY FRAME. T-DEPENDENT BACKGROUND SUBTRACTED.


Evidence for the omega pi pi decay modes of the a2 and omega(1675)

Diaz, J. ; Dibianca, F.A. ; Fickinger, W.J. ; et al.
Phys.Rev.Lett. 32 (1974) 260-264, 1974.
Inspire Record 94695 DOI 10.17182/hepdata.21339

We present evidence for the decay A20→ωπ+π0 with a branching ratio Γ(A2→ωππ)Γ(A2→ρπ)=0.28±0.09 and for the decay ω(1675)→ωπ+π− with a branching ratio Γ(ω(1975)→ωπ+π−)Γ(ω(1675)→ρπ)=0.47±0.18. Evidence is given for an intermediate B(1235)π state in the ω(1675) decay.

2 data tables

FITTED WITH BREIT-WIGNER RESONANCES PLUS BACKGROUND.

BACKGROUND SUBTRACTED TP DISTRIBUTIONS.


Backward production of rho0 and f0 mesons in pi+ n interactions at 6 gev/c

Dado, S. ; Engler, A. ; Kraemer, R.W. ; et al.
Phys.Lett.B 50 (1974) 275-279, 1974.
Inspire Record 95262 DOI 10.17182/hepdata.27950

Backward production of ϱ 0 and f 0 mesons in π + n interactions at 6 GeV/ c is presented. Total and differential cross sections are reported along with spin density matrix elements.

6 data tables

No description provided.

No description provided.

JACKSON (U) FRAME (Z=2).

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Lambda and K0 Production in Polarized p p Interactions at 6-GeV/c

Eisner, R.L. ; Fickinger, W.J. ; Glickman, S.L. ; et al.
Nucl.Phys.B 123 (1977) 361-381, 1977.
Inspire Record 4307 DOI 10.17182/hepdata.35405

Results on K 0 and Λ production in p↑p interactions at 6 GeV are presented. The data are from an exposure of the Argonne 12 ft bubble chamber to a 60% transversely polarized proton beam. Results include data on Λ and K 0 inclusive production, and on the reactions p↑p → p Λ K + (p Σ 0 K + ). The beam asymmetry parameter for p ↑ p → K 0 ( K 0 ) + X is determined to be (−0.52 ± 0.12).

1 data table

No description provided.


A Study and Comparison of the Inclusive Reactions pi+ n --> rho0 x and K- p --> anti-K*0 x

Eisner, R.L. ; Fickinger, W. ; Malko, J.A. ; et al.
Nucl.Phys.B 119 (1977) 1, 1977.
Inspire Record 4308 DOI 10.17182/hepdata.35597

Data are presented on the reactions π + n → ϱ 0 + X and K − p → K ∗0 + X at 6.0 and 7.3 GeV/ c , respectively. Comparisons are made between these two reactions and with other reactions involving inclusive vector meson production at different energies.

16 data tables

No description provided.

No description provided.

No description provided.

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STUDY OF THE REACTION P (polarized) P ---> N DELTA++ AT 6-GEV/C WITH POLARIZED BEAM

Eisner, R.L. ; Fickinger, W.J. ; Malko, J.A. ; et al.
Phys.Rev.D 20 (1979) 596-600, 1979.
Inspire Record 146629 DOI 10.17182/hepdata.24197

We have studied the reaction p↑p→nΔ++ at 6 GeV/c incident momentum in which the incident protons are 60% transversely polarized. The experiment used the Argonne National Laboratory Zero Gradient Synchrotron polarized beam and the 12-foot hydrogen bubble chamber. We report on about 6000 Δ++ events, with the Δ++ produced in the backward hemisphere in the c.m. system. Spin-density matrix elements as a function of momentum transfer are presented and small beam-polarization-induced effects are described.

4 data tables

BACKWARD-PRODUCED DEL++ HAS HALF THIS CROSS SECTION.

TWO EXPONENTIAL FITS: D(SIG)/DT HAS CHANGE OF SLOPE AT ABOUT -T OF 0.1 GEV**2.

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