INVARIANT CROSS-SECTIONS FOR THE INCLUSIVE REACTIONS anti-p p ---> pi+ X AND anti-p p ---> p X AT 22.4-GeV/c

The Alma Ata-Dubna-Helsinki-Moscow-Prague collaboration Boos, E.G. ; Ermilova, D.I. ; Samoilov, V.V. ; et al.
Nuovo Cim.A 47 (1978) 377, 1978.
Inspire Record 130221 DOI 10.17182/hepdata.37561

Invariant inclusive cross-sections for π+-mesons and protons from\(\bar pp\) reactions at 22.4 GeV/c are presented. The average multiplicity for the production of π+-mesons is 1.92±0.02 and for protons 0.41±0.02. Annihilation spectra have been approximated by using the difference between\(\bar pp\) and pp data. The resulting distributions have similar gross features as the total\(\bar pp\) data.

1 data table

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Fluctuations in Large Angle $\pi^\pm p$ Elastic Scattering

Jenkins, K.A. ; Price, L.E. ; Klem, R. ; et al.
Phys.Rev.Lett. 40 (1978) 429, 1978.
Inspire Record 6210 DOI 10.17182/hepdata.76245

Large-angle π±p elastic-scattering cross sections, measured between 2 and 9 GeV/c in fine intervals of incident momentum and scattering angle, are used to search for cross-section fluctuations occurring for small changes in the center-of-mass energy as suggested by Ericson and Mayer-Kuckuck and by Frautschi. Significant fluctuations are observed.

144 data tables

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Measurement of the Proton Proton Total Cross-Section and Small Angle Elastic Scattering at ISR Energies

Baksay, L. ; Baum, L. ; Böhm, A. ; et al.
Nucl.Phys.B 141 (1978) 1-28, 1978.
Inspire Record 136189 DOI 10.17182/hepdata.34829

Measurements of the total cross section have been performed at the ISR with c.m. energies between 23.5 GeV and 62.5 GeV. Two independent experimental methods have been applied, a measurement of total interaction rate and of small angle elastic scattering. Both experiments give consistent results showing that the total cross section increases by (11.8±1.5) % over the ISR energy range. This experiment has also measured the slope of the forward diffraction peak in elastic scattering at small momentum transfer. The elastic cross section shows the same relative rise as the total cross section, and the ratio λ of elastic to total cross section approaches a constant value of λ =0.178±0.003.

8 data tables

TOTAL CROSS SECTION FROM (INTERACTION RATE)/(LUMINOSITY). SYSTEMATIC ERROR <0.8 PCT.

TOTAL CROSS SECTION FROM APPLYING THE OPTICAL THEOREM TO SMALL ANGLE ELASTIC SCATTERING EXTRAPOLATED TO T=0.

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The Production Properties of anti-p p --> anti-Delta++ Delta++ from 3.6-GeV/c to 12-GeV/c

Donald, R.A. ; Edwards, D.N. ; Houlden, M.A. ; et al.
Nucl.Phys.B 145 (1978) 1-23, 1978.
Inspire Record 136798 DOI 10.17182/hepdata.34883

Cross sections and decay distribution moments are presented for the reaction p p → Δ ++ Δ ++ at 3.6 GeV/ c , and compared with previously published data at 9.1 and 12 GeV/ c . With the aid of the quark model, we have isolated the natural and unnatural parity exchange contributions and shown them to accord with expectations based on simple Regge-pole exchanges.

13 data tables

DOUBLE RESONANCE PRODUCTION IS 62 +- 2 PCT OF CHANNEL.

DIFFERENTIAL CROSS SECTION INTERCEPT AND SLOPE. EVENT SAMPLE DEFINED BY CUTS ON LONGITUDINAL PHASE SPACE PLOT.

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Study of Quasi Two-Body Final States in K- n Reactions at 8.25-GeV/c

Toaff, S. ; Dado, S. ; Goldberg, J. ; et al.
Nucl.Phys.B 146 (1978) 368-380, 1978.
Inspire Record 137391 DOI 10.17182/hepdata.34825

Cross sections for various channels in 3 prong + V 0 final states of K − n interactions are obtained at 8.25 GeV/ c . An energy dependence study of the quasi two-body reactions Σ − (1385) + vector meson and ΛB − seem to imply the presence of cuts in the Regge exchange formalism, whereas the reaction Δ(1236) K ∗ (890) does not require such cuts. Upper limits of 1 and 2 μb are found for the reactions K − n → Λ A 1 and K − n → Λ A 2 .

2 data tables

CROSS SECTIONS ARE CORRECTED FOR ALL RESONANCE DECAY MODES EXCEPT FOR K*- DEL0 PRODUCTION WHICH IS ONLY CORRECTED FOR UNSEEN AK0 DECAYS. NO EVIDENCE FOR NON-DIFFRACTIVE A1 AND A2 PRODUCTION.

MAXIMUM LIKELIHOOD EXPONENTIAL FITS TO DIFFERENTIAL CROSS SECTIONS.


Phi and omega Meson Production in anti-p p Annihilations at 0.7-GeV/c-0.76-GeV/c and the OZI Rule

The BOMBAY-CERN-COLLEGE DE FRANCE-MADRID collaboration Cooper-Sarkar, Amanda M. ; Ganguli, S.N. ; Malhotra, P.K. ; et al.
Nucl.Phys.B 146 (1978) 1-10, 1978.
Inspire Record 137031 DOI 10.17182/hepdata.34858

The production of the φ and ω mesons has been studied in the reactions p p → φ(ω)π + π − and p p → φ(ω) ϱ 0 at 0.70–0.76 GeV /c . The c.m. angular distribution of the φ meson in the reaction p p → φπ + π − is found to be consistent with isotropy. The corresponding distribution for ω is not. the ratio σ( p p → φπ + π − ) σ( p p → ωπ + π − ) is (10 ± 2.4) · 10 −3 , which leads to a value of (19 ± 5) · 10 −3 when corrected for the phase-space factor. Implications of this result for the OZI rule are discussed.

2 data tables

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Study of the G Meson Produced in the Reaction pi- p --> omega pi- p at 11.2-GeV/c

Forino, A. ; Quareni-Vignudelli, A. ; Cartacci, A.M. ; et al.
Nucl.Phys.B 139 (1978) 413-421, 1978.
Inspire Record 135602 DOI 10.17182/hepdata.35042

We have studied the reaction π − p → X − p followed by the decay X − → ωπ − at 11.2 GeV/ c . The partial-wave analysis in the mass range 1.36–2.0 GeV shows a clear structure in the J P = 3 − , m = 0 wave peaking at 1.67 GeV with a width of ∼0.21 GeV. We interpret this result as resulting from the g → ωπ decay. The differential cross section d σ d t is in agreement with the production of the g-meson through one-pion exchange.

4 data tables

FROM BREIT-WIGNER FIT TO <OMEGA PI-> MASS SPECTRUM. CORRECTED FOR OMEGA TAILS AND OTHER DECAY MODES. CROSS SECTION ORIGINALLY GIVEN IN R. GESSAROLI ET AL., NP B126, 382 (1977).

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LAMBDA POLARIZATION IN INCLUSIVE K- p INTERACTIONS AT 10-GeV/c AND 16-GeV/c

The Aachen-Berlin-CERN-London-Vienna collaboration Grassler, H. ; Honecker, R. ; Laven, H. ; et al.
Nucl.Phys.B 136 (1978) 386, 1978.
Inspire Record 129719 DOI 10.17182/hepdata.35096

A strong negative transverse polarization P z is found for forward produced lambdas observed in 10 and 16 GeV/ c K − p interactions. This indicates that exchanges of natural spin-parity are dominant in the production process. Using the polarization results, the d σ d u′ distributions for natural and unnatural spin-parity exchanges are derived. For unnatural exchanges, a dip is observed at u ′≅0.3 GeV 2 , which can be explained as a nonsense-wrong-signature zero of the N β trajectory. The value of P z for forward producted lambdas is constant with energy. This is in agreement with the triple-Regge model prediction, as is the fact that P z is constant as a function of M 2 s . The two non-transverse polarization components, P x and P y , have been measured and are found to be consistent with zero for all x values, unlike P z .

4 data tables

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Measurement of the Polarization of the Lambda0 in the Reaction gamma p --> K+ Lambda0 in the Resonance Region

Haas, R. ; Miczaika, T. ; Opara, U. ; et al.
Nucl.Phys.B 137 (1978) 261-268, 1978.
Inspire Record 135344 DOI 10.17182/hepdata.35123

At the Bonn 2.5 GeV synchrotron the polarization of the Λ 0 was measured at 40° and 90° for three energies. The kaon was detected with a strong focussing magnetic spectrometer and separated from other particles with the help of a differential liquid Čerenkov counter. The polarization was determined by means of the angular distribution of the decay proton which was measured with a combination of sonic spark chambers and a scintillation counter hodoscope. The typical statistical errors are about 13%. The systematic errors add up to 8%.

1 data table

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DIFFRACTION AND RESONANCE PRODUCTION IN EXCLUSIVE ANTI-P P INTERACTIONS AT 100-GEV/C.

Bust, C.P. ; Carter, J.R. ; Neale, W.W ; et al.
Nucl.Phys.B 140 (1978) 409-422, 1978.
Inspire Record 132548 DOI 10.17182/hepdata.34985

We have investigated the reactions p p π + π − a ̊ and p p a ̊ p p 2π + 2π − at 100 GeV /c . The p p π + π − final state is dominated by diffractive production of a p π + π − ( or p π + π − ) system which shows a strong tendency to form Δ ++ π − ( or Δ ++ π + ) . The process p p a ̊ Δ ++ Δ ++ is also observed in this reaction, indicating an energy dependence of s −1.5±0.1 . The p p 2π + 2π − channel shows less single diffraction, and has a doubly diffractive component consistent with pomeron factorization. Strong Δ ++ ( Δ ++ ) production is agoain seen, but in contrast to the p p π + π − channel we also observe considerable ϱ 0 production.

1 data table

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