RESONANCE PRODUCTION IN THE REACTION PI+- P ---> K0(S) K+- P AT 30-GEV/C AND 50-GEV/C

Cleland, W.E. ; Delfosse, A. ; Dorsaz, P.-A. ; et al.
Nucl.Phys.B 208 (1982) 228-261, 1982.
Inspire Record 184972 DOI 10.17182/hepdata.34061

The mass and momentum transfer spectra of the charged K K system produced in the reaction π ± p→K s 0 K ± p are analyzed. The data have been collected at the CERN SPS with the Geneva-Lausanne two-arm, non-magnetic spectrometer at 30 and 50 GeV/ c incident momenta. The general features of the reactions at these energies and the results of partial-wave analyses of the two kaon system are presented. The channel is dominated by the diffractive production of even spin resonances. The spin 4 recurrence of the A 2 (1320) is clearly observed at 2040 MeV ( Γ =380 MeV. A new resonance is observed with a mass M =2450MeV and a width Γ =400 MeV; the quantum numbers of this state are found to be I G ( J PC )=1 −(6 ++ ) . The analysis also shows the decay of the decay of the meson ϱ′(1600) through the K K channel at both energies. The production amplitudes are determined both as a function of the K K effective mass and of the momentum transfer. Isoscalar natural parity exchange is dominant. The 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. We compare the production mechanisms of the 2 + resonances A 2 (1320) and K ∗ (1430). Finally, we estimate the K K branching ratios of the spin 4 A 2 (2040) and spin 6 A 2 (2450) resonances.

5 data tables

No description provided.

D(SIG)/DT FOR 50 GEV IN RESONANCE REGIONS.

No description provided.

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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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A2+ production in 5.45 gev/c pi+ p interactions

Bloodworth, I.J. ; Jackson, W.C. ; Prentice, J.D. ; et al.
Nucl.Phys.B 37 (1972) 203-211, 1972.
Inspire Record 75334 DOI 10.17182/hepdata.32963

We report on A + 2 production in a π + p experiment at 5.45 GeV/ c . The fitted values for the mass and width are given, and the production characteristics are illustrated by the momentum transfer distributions and average density matrix elements. A depletion of events is observed near 1.3 GeV which favours a double pole amplitude or two interfering resonances over a simple Breit-Wigner formula.

3 data tables

No description provided.

PLOT V. T IN FIG. 2(A) NOT COMPILED.

D.M.E'S DETERMINED BY ASSUMING RHO22=0,RHO00=1-2RHO11.


A2+ mass spectrum in pi+ p interactions at 3.7 gev/c

Barnham, K.W.J. ; Abrams, G.S. ; Butler, W.R. ; et al.
Phys.Rev.Lett. 26 (1971) 1494-1498, 1971.
Inspire Record 68979 DOI 10.17182/hepdata.21630

A study of the A2+ mass spectrum in π+p interactions at 3.7 GeVc is presented. For a cut of t′=0.1−2.0 GeV2 and on eliminating the Δ++ we find that the three-pion mass spectrum in the A2+ region is fitted by the dipole formula with a confidence level of 53% and a single Breit-Wigner formula with a confidence level of 11%. Our result thus favors A2+ splitting although a single Breit-Wigner fit cannot be ruled out. We also report the A2+ decay branching fractions measured over all t′ values. They are 0.78 ± 0.05, 0.15 ± 0.04, 0.06 ± 0.03, and < 0.02 for ρπ, ηπ, KK¯, and η′π, respectively, in good agreement with other experiments.

1 data table

No description provided.


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).

No description provided.


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.


Forward A2+ in Two-dimensions Production in $\pi^+ p \to K^+ \bar{K}(s$)0 $p$ at 12.7-{GeV}/$c$

Hyams, B. ; Jones, C. ; Weilhammer, P. ; et al.
Nucl.Phys.B 146 (1978) 303-326, 1978.
Inspire Record 132236 DOI 10.17182/hepdata.34849

Approximately 350 A 2 + events have been observed in the reaction π + p → K + K S 0 p ( K S 0 → π + π − ) at an incident π + laboratory momentum of 12.7 GeV/ c . The events are distributed over a range of four-momentum transfer squared 0.01 ⩽ − t ⩽ 0.60 (GeV/ c ) 2 and K + K S 0 mass 1.11 ⩽ m K + K S 0 ⩽ 1.51 GeV . A Breit-Wigner fit to the mass spectrum yields a mass for the A 2 + , m A 2 + = 1.324 ± 0.005 GeV, and a width Γ 0 = 0.110 ± 0.018 GeV. We find a cross section σ ( π + p → A 2 + p) = 1.71 ± 0.30 μb referring to the above-mentioned mass and t range and A 2 + → K + K S O with K S 0 → π + π − . The spin-space density matrix in the Gottfried-Jackson frame is practically saturated by ϱ 11 ⋍ ϱ 1−1 = 1 2 suggesting natural parity exchanges only. There is a forward dip in the angular distribution consistent with dominance of s -channel net helicity flip amplitudes and ϱ and f Regge exchanges suffice to describe adequately our differential cross sections.

5 data tables

SUBTRACTED BACKGROUND IS PHASE SPACE. FITTED D(SIG)/DT SLOPE IS 9.5 +- 0.9 GEV**-2.

SUBTRACTED BACKGROUND IS AN S-WAVE WITH SLOPE OF 8 GEV**-2. FITTED D(SIG)/DT SLOPE IS 6.9 +- 0.6 GEV**-2.

FROM D(SIG)/DT. ERROR INCLUDES 15 PCT SCALE ERROR ADDED QUADRATICALLY.

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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.


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.


Partial Wave Analysis of the (pi+ pi+ pi-) System Through the Region of the A3 Meson

Thompson, G. ; Badewitz, R.C. ; Gaidos, J.A. ; et al.
Nucl.Phys.B 69 (1974) 381-398, 1974.
Inspire Record 760 DOI 10.17182/hepdata.32348

A recent spin-parity analysis of the π + π + π − system formed opposite a proton and a coherent deuteron by incident 13 GeV/ c 2 π + mesons, is extended to a three-pion mass of 1.9 GeV/ c . Relative proportions of the contributing partial waves are presented, from threshold, and the A 3 region is discussed in detail. Contrary to results with the (3 π ) − system, a change in phase is noted for the 2 − amplitude decaying to f 0 π + via am S-wave.

7 data tables

FOR A3+ DEFINED AS 2+ S-WAVE WITH 1.5 < M(3PI) < 1.8 GEV).

CONSTRAINT IMPLIES RHO(11) + RHO(1-1) = 0.

CONSTRAINT IMPLIES RHO(11) + RHO(1-1) = 0.

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