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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STUDY OF THE REACTIONS K+- P ---> K0(S) PI+- P AT 30-GEV/C AND 50-GEV/C: DESCRIPTION OF THE APPARATUS AND AMPLITUDE ANALYSIS OF THE K0(S) PI SYSTEM

Cleland, W.E. ; Delfosse, A. ; Dorsaz, P.-A. ; et al.
Nucl.Phys.B 208 (1982) 189-227, 1982.
Inspire Record 184971 DOI 10.17182/hepdata.34081

The reactions K ± p→K s 0 π ± p are studied at 30 and 50 GeV/ c . Data for these reactions were obtained using the Geneva-Lausanne spectrometer whose main characteristics are: (i) large forward acceptance; (ii) high-resolution time-of-flight for recoil proton momentum measurement; (iii) high data-taking rate and on-line pattern recognition. The K ∗ (1 − ), K ∗ (2 + ), K ∗ (3 − ) and K ∗ (4 + ) resonance parameters and production cross sections are determined. The K π production amplitudes are calculated both as a function of the K π mass and of the momentum transfer. Isoscalar natural parity exchange (NPE) is dominant. The NPE amplitudes are decomposed into pomeron- f-, ω-exchange contributions, and their energy dependence between 10 and 50 GeV/ c is shown to be well-described by a Regge pole model based on the f-dominated pomeron hypothesis.

5 data tables

CORRECTED TO INCLUDE BW TAILS AND THE FRACTION OF EVENTS OUTSIDE THE T-ACCEPTANCE OF THE SPECTROMETER.

FITS OF THE FORM -A*TP*EXP(BTP) ARE MADE BY THE AUTHORS AND THE VALUES OF A AND B ARE GIVEN HERE. MASS REGIONS OF THE FIT ARE:-. K*(890) 0.84 < M <0.94 GEV. K*(1430) 1.36 < M <1.5 GEV. K*(1780) 1.68 < M <1.88 GEV.

FITS OF FORM -A*TP*EXP(BTP) ARE MADE BY THE AUTHORS AND THE VALUES OF A AND B ARE GIVEN HERE. MASS REGIONS OF THE FIT ARE:-. K*(890) 0.84 < M <0.94 GEV. K*(1430) 1.36 < M <1.5 GEV. K*(1780) 1.68 < M <1.88 GEV.

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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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Forward $K^*$+ (892) Production in $K^+ p \to \pi^+ K^0_S p$ at 12.7-{GeV}/$c$

Sacharidis, E.J. ; Blum, W. ; Dietl, H. ; et al.
Nucl.Phys.B 179 (1981) 9-32, 1981.
Inspire Record 154321 DOI 10.17182/hepdata.34347

We have measured 618 K + p → π + K S 0 p events at 12.7 GeV/ c incident lab momentum, mass range 790 ⩽ m π + K s 0 ⩽ 990 MeV and t range 0.01 ⩽ − t ⩽ 0.60 (GeV/ c ) 2 . The π + K S 0 mass spectrum is dominated by the K ∗+ (892) resonance and a Breit-Wigner fit yields a mass m = 893.5 ± 1.1 MeV and a width Γ = 33.2 ± 4.1 MeV which is much narrower than measured hitherto. The t distribution of K ∗+ (892) events shows a dip in the forward direction and an exponential fall off thereafter, consistent with dominance of helicity flip amplitudes. The spin density matrix is almost saturated by ρ 11 and ρ 1−1 which are very close to their maximum allowed value of 1 2 throughout the measured t range except in the very forward direction where ρ 00 and Re ρ 10 deviate from zero. Natural parity exchanges, therefore, dominate with unnatural parity exchanges being restricted to a small region in the forward direction. A Regge pole analysis of the differential cross sections of the present measurement in conjunction with previously measured total cross sections supports the f-coupled-pomeron hypothesis.

3 data tables

SUBTRACTED BACKGROUND IS PHASE SPACE.

SUBTRACTED BACKGROUND IS AN INCOHERENT S-WAVE WITH EXPONENTIAL T-DEPENDENCE WITH SLOPE OF 6 GEV**-2.

Axis error includes +- 15/15 contribution.


NONDIFFRACTIVE TWO-BODY CHANNELS IN REACTIONS K+ P ---> K0 PI+ P AND K+ P ---> K+ PI- PI+ P AT 32-GeV/c. FRANCE-SOVIET UNION AND CERN-SOVIET UNION COLLABORATIONS

Givernaud, A. ; Cochet, C. ; Denegri, D. ; et al.
Nucl.Phys.B 153 (1979) 280-298, 1979.
Inspire Record 146578 DOI 10.17182/hepdata.34765

We present results on a number of non-diffractive two-body channels contributing to reactions K + p→K 0 π + p and K + p→K + π − π + p. The data come from an exposure of the Mirabelle bubble chamber to an r.f. separated K + beam of 32 GeV/ c at the Serpukhov accelerator. Total cross sections are given for the final states K ∗+ (890) p , K ∗+ (1420) p , K 0 Δ ++ (1232), K ∗+ (890) p , Δ ++ (1232), K ∗0 (1420) Δ ++ (1232), K ∗0 (1780) Δ ++ (1232) and K ∗0 (890) Δ ++ (1950) . The differential cross sections are given for all channels with sufficient statistics. The energy dependence of the total and differential cross sections is studied.

3 data tables

FROM K0 P PI+ FINAL STATE.

DOUBLE RESONANCE CHANNEL CROSS SECTIONS CORRECTED FOR BACKGROUND, BREIT-WIGNER TAILS AND DIFFRACTIVE PROCESSES.

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Amplitude and Natural Parity Exchange Analysis of K+- p --> (K pi)+- p Data at 10-GeV/c

Martin, Alan D. ; Shimada, T. ; Baldi, R. ; et al.
Nucl.Phys.B 134 (1978) 392-412, 1978.
Inspire Record 122126 DOI 10.17182/hepdata.35128

High statistics data for the reactions K ± p → K S 0 π ± p at 10 GeV/ c are analysed. The K ∗ (1 − ), K ∗ (2 + ), and K ∗ (3 − ) resonance parameters and production cross sections are calculated. The Kπ production amplitudes are determined as a function of t and the produced Kπ mass. Isoscalar natural-parity-exchange (NPE) is dominant. The t dependence of the K ± NPE amplitudes have a cross-over at t = −0.3 (GeV/ c ) 2 for both K ∗ (890) and K ∗ (1420) production, being more pronounced for the K ∗ (1420). Natural-parity-exchange interference effects are isolated. The NPE amplitudes are decomposed into pomeron-, f-, and ω-exchange contributions. S-wave Kπ production is found to be consistent with the Kπ partial-wave analyses of charge-exchange reactions.

2 data tables

CORRECTED FOR BACKGROUND, BREIT-WIGNER TAILS AND T-ACCEPTANCE. SYSTEMATIC ERROR INCLUDED.

DATA FOR K PI PRODUCTION AND ANGULAR DISTRIBUTIONS ARE IN THE PRECEDING PAPER, R. BALDI ET AL., NP B134, 365 (1978).


Systematic Study of K pi Production in the Reaction K+- p --> K0(s) pi+- p: Technique and Measurements at 10-GeV/c

Baldi, R. ; Bohringer, T. ; Dorsaz, P.A. ; et al.
Nucl.Phys.B 134 (1978) 365-391, 1978.
Inspire Record 122145 DOI 10.17182/hepdata.8292

A two-arm spectrometer for simple event topologies is described. Its main characteristics are: (i) large solid-angle acceptance for the forward emitted particles, owing to the absence of magnetic-momentum analysis; (ii) high-resolution time-of-flight measurement of the recoil proton, in the momentum-transfer range 0.05 < | t | < 1 (GeV/ c ) 2 ; (iii) high data-taking rate and on-line pattern recognition.

6 data tables

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K*(892)+ REGION.

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Charged K* (890) Production at 13-GeV/c

Estabrooks, P. ; Carnegie, R.K. ; Brandenburg, G.W. ; et al.
Phys.Rev.D 17 (1978) 658, 1978.
Inspire Record 120824 DOI 10.17182/hepdata.24375

We present high-statistics data on differential cross sections and density matrix elements for K*±(890) production obtained in a 13-Gev/c SLAC experiment. The most remarkable features of the data are the dominance of natural-parity exchange and significant differences between K*+ and K*− production by natural-parity isoscalar exchange. We present two exchange models which successfully describe this difference, as well as the overall t dependence: model A including Pomeron plus strongly exchange-degenerate Regge poles and model B involving broken exchange degeneracy for the f and ω exchanges. These two phenomenological models lead to different predictions for the energy dependence of K*± production, for the relative K*(1420)K*(890) production rate, and for the SU(3)-related ρ± production processes.

4 data tables

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Amplitudes and Exchange Mechanisms for K* Resonances Produced by the Reactions K+- p --> K*+- p at 10-GeV/c

Baldi, R. ; Bohringer, T. ; Dorsaz, P.A. ; et al.
Phys.Lett.B 70 (1977) 377-382, 1977.
Inspire Record 126179 DOI 10.17182/hepdata.27517

We compare production of the low mass K π -resonances by K + and K − beams in the non-charge-exchange reactions K ± p → K 0 s π ± p at 10 GeV/ c . High statistics data, obtained with the same apparatus, allow extraction of the K ∗ (890) and K ∗ (1420) production amplitudes corresponding to unnatural and natural parity exchange in the t -channel. The NPE-part dominates in both charge states. Its t -dependence shows a strong crossover at t ≈ −0.3 (GeV/ c ) 2 for the K ∗ (1420). For the K ∗ (890) the crossover is weaker but it occurs at the same value of t . This behaviour can be explained by pomeron, f and ω Regge exchange contributions to the NPE amplitude. The UPE amplitudes agree, both in normalisation and t -dependence, with the expectations of π and B exchange as isolated from data for the charge exchange reaction K − p → (K − π + )n.

1 data table

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Resonance Production in the Reaction K+ p --> K0 p pi+ at 5-GeV/c, 8.25-GeV/c and 16-GeV/c

Colley, D.C. ; Carney, J.N. ; James, M.F. ; et al.
Nucl.Phys.B 110 (1976) 333-354, 1976.
Inspire Record 108770 DOI 10.17182/hepdata.35742

We present a systematic analysis of the production of K ∗+ (892) and Δ ++ (1236) resonances in the K + p → K 0 p π + reaction at 5, 8.25 and 16 GeV/ c . We have measured total cross sections, differential cross sections, density matrix elements and examined resonance production mechanisms in terms of the exchange of states with definite naturality. Some results on the reaction K + p → K ∗+ (1420) p are also given.

6 data tables

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