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

No description provided.

No description provided.


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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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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Inclusive Production of K* (890), Sigma (1385) and S* (993) Resonances in anti-p p Interactions at 12-GeV/c Incident Momentum

Baland, J.F. ; Grard, F. ; Herquet, P. ; et al.
Nucl.Phys.B 140 (1978) 220-234, 1978.
Inspire Record 135964 DOI 10.17182/hepdata.35033

The reactions p p → K ∗ (890) X , p p →Σ ± (1385) X and p p → S ∗ (993) X at 12 GeV/ c incident momentum have been studied using 19 000 events with a visible V 0 decay in BEBC. Inclusive production cross sections of these resonances as a function of transverse momentum and rapidity are presented. The contribution of annihilation to the production of the K ∗ (890) is investigated from a comparison with the corresponding pp data.

3 data tables

COMBINDED K*+ AND K*- DATA IN THIS TABLE.

COMBINDED K*+ AND K*- DATA IN THIS TABLE.

No description provided.


Observation of a Narrow Resonance Formed in e+ e- Annihilation at 9.46-GeV

The Pluto collaboration Berger, Christoph ; Lackas, W. ; Raupach, F. ; et al.
Phys.Lett.B 76 (1978) 243-245, 1978.
Inspire Record 130053 DOI 10.17182/hepdata.27457

An experiment using the PLUTO detector has observed the formation of a narrow, high mass, resonance in e + e − annihilations at the DORIS storage ring. The mass is determined to be 9.46±0.01 GeV which is consistent with that of the Upsilon. The gaussian width σ is observed as 8±1 MeV and is equal to the DORIS energy resolution. This suggests that the resonance is a bound state of a new heavy quark-antiquark pair. An electronic width Γ ee =1.3±0.4 keV was obtained. In standard theoretical models, this favors a quark charge assignment of 1 3 .

1 data table

No description provided.


A Partial Wave Analysis of the ($\bar{K}0 \pi^+ \pi^-$) System Produced in $K^- p \to \bar{K}0 \pi^+ \pi^- n$ at 10-{GeV}/$c$

Konigs, E. ; Otter, G. ; Ransone, G. ; et al.
Phys.Lett.B 74 (1978) 282-286, 1978.
Inspire Record 6169 DOI 10.17182/hepdata.27445

A partial wave analysis of the non-diffractively produced ( K ̄ 0 π + π - system has been performed. The system was produced in the reaction K - p→ K ̄ 0 π + π - n at 10 GeV/ c , measured in the CERN Omega spectrometer. Besides the well-known K ∗ (1420) resonance, we find good evidence for the production of Q 2 (1400) and some indication for Q 1 (1290) production in J P =1 + . In addition we clearly observe a bump in the 1800 MeV region, the properties of which are discussed.

3 data tables

BR(<K RHO>/<K* PI>) FOUND TO BE 0.21 +- 0.08 AND 0.9 +- 0.3 FOR K*(1420) AND K*(1780) RESPECTIVELY.

DENSITY MATRIX FOR JP=2+ IN THE REGION 1.3 < M(K PI PI) < 1.55 GEV.

DENSITY MATRIX FOR JP=3- IN THE REGION 1.6 < M(K PI PI) < 1.9 GEV.


Backward Enhancement in the a1 Region and a2 Production in the Region pi- p --> p(f) pi+ pi- pi- at 9-GeV/c and 12-GeV/c

Ferrer, A. ; Bouquet, B. ; D'Almagne, B. ; et al.
Phys.Lett.B 74 (1978) 287-291, 1978.
Inspire Record 134669 DOI 10.17182/hepdata.27446

Results on backward (3 π ) - system produced in π - p→p f π + π - π - reaction at 9 and 12 GeV/ c are given. The ϱ 0 π - mass spectra show two clear signals at 1050 MeV (A 1 region) and 1303 MeV (A - 2 ). The width of the enhancement in the A 1 region (195±32 MeV) is narrower than found in diffractive experiments. Total backward cross sections for those signals are of the same order of magnitude (∼0.5 μb).

1 data table

No description provided.


Pion Form-Factor from 480-MeV to 1100-MeV

Quenzer, A. ; Ribes, M. ; Rumpf, F. ; et al.
Phys.Lett.B 76 (1978) 512-516, 1978.
Inspire Record 134061 DOI 10.17182/hepdata.27443

The pion form factor is measured in the reaction e + e − → π + π − for center of mass energies in the range 480–1100 MeV. Our results are first analysed in terms of the conventional Vector Meson Dominance formalism, and then taking into account the ωπ inelastic channel. The result of this later formalism is a pion form factor ( F π ) which fits quite well all the existing data on F π both in the timelike and spacelike regions, and pion mean square radius of 〈 r π 2 〉 = 0.460 ± 0.011 fm 2 or 〈r π 2 〉 1 2 = 0.678 ± 0.008 fm .

1 data table

No description provided.


Sharp Backward Peak in p He-4 Elastic Scattering at 1.05-GeV

Berger, J. ; Duflo, J. ; Goldzahl, L. ; et al.
Phys.Rev.Lett. 41 (1978) 152-155, 1978.
Inspire Record 135350 DOI 10.17182/hepdata.20833

p-He4 elastic scattering has been measured at 1.05-GeV incident proton energy, close to 180° in the center of mass. The steep backward peak observed at lower energies is still present, but its slope appears to decrease.

1 data table

No description provided.


Polarization Measurement of the $\Sigma^+$ Produced in the Line Reversed Reactions $\pi^+ p \to K^+ \Sigma^+$ and $K^- p \to \pi^- \Sigma^+$ at 7-{GeV}/$c$ and 11.6-{GeV}/$c$

Baker, P.A. ; Chima, J.S. ; Dornan, P.J. ; et al.
Phys.Rev.Lett. 40 (1978) 678, 1978.
Inspire Record 129108 DOI 10.17182/hepdata.20914

The polarization of the Σ+ has been measured for the line-reversed reactions π+p→K+Σ+ and K−p→π−Σ+ at 7 and 11.6 GeV/c using the SLAC Hybrid Facility. Since the Σ+ decay is observed in the bubble chamber, the trigger of the flash lamps on a fast K+(π−) did not bias the polarization measurements. We find that the Σ+ polarizations from the two reactions have opposite signs but similar magnitudes and are in much better agreement with the predictions of weak exchange degeneracy than previous lower-energy comparisons.

1 data table

No description provided.