Comparison of 20 exclusive reactions at large t

White, C. ; Appel, R. ; Barton, D.S. ; et al.
Phys.Rev.D 49 (1994) 58-78, 1994.
Inspire Record 377535 DOI 10.17182/hepdata.50306

We report a study of 20 exclusive reactions measured at the AGS at 5.9 GeV/c incident momentum, 90° center of mass. This experiment confirms the strong quark flow dependence of two-body hadron-hadron scattering at large angle. At 9.9 GeV/c an upper limit had been set for the ratio of cross sections for (p¯p→p¯p)(pp→pp) at 90° c.m., with the ratio less than 4%. The present experiment was performed at lower energy to gain sensitivity, but was still within the fixed angle scaling region. A ratio R(p¯ppp)≈140 was measured at 5.9 GeV/c, 90° c.m. in comparison to a ratio near 1.7 for small angle scattering. In addition, many other reactions were measured, often for the first time at 90° c.m. in the scaling region, using beams of π±, K±, p, and p¯ on a hydrogen target. There are similar large differences in cross sections for other reactions: R(K−p→π+Σ−K−p→π−Σ+)≈112, for example. The relative magnitudes of the different cross sections are consistent with the dominance of quark interchange in these 90° reactions, and indicate that pure gluon exchange and quark-antiquark annihilation diagrams are much less important. The angular dependence of several elastic cross sections and the energy dependence at a fixed angle of many of the reactions are also presented.

21 data tables

Cross sections at 90 degrees in the centre-of-mass.

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Comparison of Exclusive Reactions at Large $T$

Baller, B.R. ; Blazey, G.C. ; Courant, H. ; et al.
Phys.Rev.Lett. 60 (1988) 1118-1121, 1988.
Inspire Record 264273 DOI 10.17182/hepdata.3063

Cross sections or upper limits are reported for 12 meson-baryon and two baryon-baryon reactions for an incident momentum of 9.9 GeV/c, near 90° c.m.: π±p→pπ±,pp±,π+°±,K+Σ±, (Λ0/Σ0)K0; K±p→pK±; p±p→pp. By studying the flavor dependence of the different reactions, we have been able to isolate the quark-interchange mechanism as dominant over gluon exchange and quark-antiquark annihilation.

2 data tables

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Production of $\rho^\pm$, $G^\pm$(1700), $A2^\pm$, $K^{*\pm}$(890) and $K^{*\pm}$(1420) at 50-{GeV}/c

Delfosse, A. ; Dorsaz, P.A. ; Extermann, P. ; et al.
Nucl.Phys.B 183 (1981) 349-366, 1981.
Inspire Record 170363 DOI 10.17182/hepdata.34280

Mesons decaying into π 0 or η and one charged meson were studied using a liquid-argon calorimeter in a non-magnetic double-arm spectrometer. Cross sections and energy dependences are presented. The ϱ ± production mechanisms are discussed in detail: ω and π exchange contribute the largest fractions, but also A 2 exchange is present. ϱ ± production by ω exchange is shown to follow the energy behaviour predicted by the Regge trajectory α ω ( t ) = 0.4 − | t |.

2 data tables

Axis error includes +- 0.0/0.0 contribution (13 TO 25////STATISTICAL ERRORS ARE SMALLER THAN THE SYSTEMATIC ERRORS).

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Investigation of rho+, rho- and rho0 Production in pi+ p Interactions at 16-GeV/c and p p Interactions at 24-GeV/c and Quark Model Predictions

The Bonn-Hamburg-Munich & Aachen-Bonn-CERN-Cracow-Warsaw collaborations Bockmann, K. ; Heilmann, H.G. ; von Holt, K. ; et al.
Nucl.Phys.B 140 (1978) 235, 1978.
Inspire Record 122675 DOI 10.17182/hepdata.35023

Quasi-inclusive and total inclusive ϱ + , ϱ − and ϱ 0 cross sections have been studied, using data of a π + p and a pp bubble chamber experiment at 16 and 24 GeV/ c , respectively. In pp collisions it is found that the total inclusive cross sections for ϱ 0 , ϱ + and ϱ − production are about equal. This equality also holds for the differential cross sections d σ/ d y ∗ , all showing the characteristics of dominantly central production. In the π + p reactions the ϱ − are mainly produced centrally, whereas there are strong additional contributions in the beam fragmentation region for ϱ + and ϱ 0 mesons. In the central region, however, the cross sections for ϱ + , ϱ − and ϱ 0 production are almost equal within errors. All our findings agree with what is expected from quark model predictions.

1 data table

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Cross-Section Measurement for Nonstrange Final States and Single Pion Production in pi+ p Interactions at 3.6-GeV/c

Macnaughton, J. ; Butler, W.R. ; Coyne, D.G. ; et al.
Phys.Rev.D 15 (1977) 1832-1845, 1977.
Inspire Record 124169 DOI 10.17182/hepdata.24652

Cross sections are presented for all final states without strange-particle production. Contributions to single-pion production are found from (i) Δ(1238)π, (ii) ρ+p, (iii) nucleon diffractive dissociation into Nπ, (iv) N*(1688)π+, and (v) "phase space." Processes (i), (ii), and (iii) are studied in some detail taking into account overlaps between the various subchannels.

10 data tables

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'JM'.

'JM'. USING DATA WITH 1.12 < M(P PI+) < 1.32 GEV AND COS(P PI DECAY ANGLE IN JACKSON FRAME) < 0.

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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

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

The AACHEN-BERLIN-BONN-CERN-CRACOW-HEIDELBERG collaboration Deutschmann, M. ; Schmitz, P. ; Schulte, R. ; et al.
Nucl.Phys.B 86 (1975) 221, 1975.
Inspire Record 104924 DOI 10.17182/hepdata.32122

A study of the reaction π + p → p π + π o at 16 GeV/ c incident momentum has been made using the prism plot analysis to reject background events arising from elastic and multineutral contaminations and to separate different reaction channels ( ϱ + p, g + p, Δ + π + , Δ ++ π o , π + (p π o ) DD ). Cross sections, invariant mass distributions and production and decay angular distributions are presented. For the channel corresponding to proton diffraction dissociation strong violation of both s - and t -channel helicity conservation is found for low values of the (p π o ) mass. We demonstrate that the prism plot method provides a better separation of background events than conventional methods using kinematic cuts.

2 data tables

STATISTICAL ERRORS ONLY.

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An Investigation of rho Meson Production in pi p Interactions at 3.9-GeV/c

Haber, B. ; Hodous, M.F. ; Hulsizer, R.I. ; et al.
Phys.Rev.D 10 (1974) 1387, 1974.
Inspire Record 819 DOI 10.17182/hepdata.25008

We have investigated the ρ-meson production mechanism in the three reactions π±p→ρ±p and π−p→ρ0n at 3.9 GeV/c (s=8.2 GeV2) using the prism-plot technique. Differential cross sections at all momentum transfers are presented. A significant backward peak has been found in all three reactions. The differential cross sections for these backward peaks are given and are compared with the equivalent pion elastic and charge-exchange cross sections in the backward direction. Using a linear combination of the three differential cross sections we have isolated the I=0 exchange contribution in the forward direction. This differential cross section has a zero at −t=0.45 (GeV/c)2 and is fitted by the dual absorptive model of Harari with an interaction radius of ∼ 1.2 F. The total I=0 cross section is calculated and compared with similarly determined cross sections at higher momenta. An analysis of the properties of the other possible spin-parity exchanges is also presented.

8 data tables

SLOPE FITTED OVER 0.05 < -T < 0.3 GEV**2.

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The pi+ p interaction at 1.2 gev/c

Berthon, A. ; Mas, J. ; Narjoux, J.L. ; et al.
Nucl.Phys.B 81 (1974) 431-444, 1974.
Inspire Record 93412 DOI 10.17182/hepdata.7945

Experimental results are presented for the available channels in the 1.2 GeV/ c π + p interaction. An isobaric model with incoherent addition of the amplitudes is used to determine the π, Δ and N ∗ abundance rates in the π + π o p final state. The multipole parameters in the density matrix of the Δ ++ are determined as functions of its production angle.

7 data tables

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LEGENDRE POLYNOMIAL FIT USED TO CORRECT FOR ELASTIC EVENTS LOST FROM THE FORWARD BIN.

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Two-prong fitted channels at 11.7 gev/c

Evans, D. ; Neat, K. ; Caso, C. ; et al.
Nuovo Cim.A 16 (1973) 299-314, 1973.
Inspire Record 87004 DOI 10.17182/hepdata.37784

A sample of 43000 two-prong events obtained at a momomentum of 11.7 GeV/c is used to determine the cross-sections of the fitted channels, and to study the reaction π+p→π+pπ0. We investigate in particular the quasi-two-body channels π0Δ++ and ρ+p.

6 data tables

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