Comparison of ø production by π, K and p incident on protons at 10 GeV

Baldi, Ranieri D.; Böhringer, T.; Dorsaz, P.A.; Hungerbühler, V.; Kienzle-Focacci, M.W.; Martin, Michel; Mermoud, André; Nef, C.; Siegrist, P.

doi:10.1016/0370-2693(77)90499-3

Cited by 31 publications

(8 citation statements)

References 8 publications

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“…The space between upper solid and dashed curves indicates upper and lower limits for the OBE model prediction. In spite of the fact that the OBE model is reliable in the region of ∆ ≤ 0.2 GeV it fits satisfactorily the available experimental data [9,25] in a much wider interval. The cross section for the pn reaction is greater by a factor ≃ 5 as given already in our threshold-near prediction above.…”

Section: Resultssupporting

confidence: 56%

Polarization observables in the reactionNN→NNφ

1999

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Section: Resultssupporting

confidence: 56%

Polarization observables in the reactionNN→NNφ

1999

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“…Taking into account the effects of the finite meson widths on the phase space [12,22] changes R OZI by at most 5% at the lowest excess energies. The production ratio obtained from high energy ppV data is ∼ (1 − 2.4) × R OZI [14,15,16]. Together with our findings, this means that there must be a significant energy dependence of the OZI enhancement factor [22], which requires more theoretical work to understand its origin.…”

mentioning

confidence: 84%

“…Two total cross sections of φ production have been obtained for ǫ ∼ (2 − 4) GeV, but with rather limited accuracy [15,16]. At low excess energy, a single measurement of total and differential cross sections has been made by the DISTO collaboration at ǫ = 83 MeV [17].…”

mentioning

confidence: 99%

Near-Threshold Production ofϕMesons inppCollisions

Hartmann¹,

Maeda²,

Keshelashvili³

et al. 2006

Phys. Rev. Lett.

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The pp → ppφ reaction has been studied at the Cooler Synchrotron COSY-Jülich, using the internal beam and ANKE facility. Total cross sections have been determined at three excess energies ǫ near the production threshold. The differential cross section closest to threshold at ǫ = 18.5 MeV exhibits a clear S-wave dominance as well as a noticeable effect due to the proton-proton final state interaction. Taken together with data for ppω-production, a significant enhancement of the φ/ω ratio of a factor 8 is found compared to predictions based on the Okubo-Zweig-Iizuka rule.PACS numbers: 25.10.+s, 13.75.-n Meson production near threshold has the potential to clarify important questions of hadron physics in the nonperturbative regime of quantum chromodynamics due to its comparatively simple scheme of interpretation. The production of light vector mesons, ρ(770), ω(782) and φ(1020), quark anti-quark states with their spins aligned (J P =1 − ) and without open strangeness, has been investigated with both hadronic and electromagnetic probes in order to study production mechanisms [1], coupling constants [1], modifications in nuclear medium [2] and in particular the so-called Okubo-Zweig-Iizuka (OZI) rule [3]. This rule states that processes with disconnected quark lines between initial and final states are suppressed compared to those where the incident quarks continue through to the exit channel. As a result, the production of ideally mixed φ-mesons (quark content ss) in a reaction A + B → φX is reduced compared to A + B → ωX (ω is a linear combination of uū + dd) under similar kinematical conditions. Taking into account deviations from ideal mixing between singlet and octet vector mesons, Lipkin predicted a ratio of single φ to ω production of R φ/ω = 4.2 × 10 −3 ≡ R OZI [4,5]. However, strong enhancements of the experimental R φ/ω compared to R OZI have been observed (an overview is given in Ref.[6]), in particular inpp annihilations, where R φ/ω can be as large as ∼ 100×R OZI [7]. Here a strong correlation of the φ meson yield with the spin-triplet fraction of the initial state was found [8], and this in part motivated the suggestion of a polarized internal strangeness component in a polarized nucleon [9]. However, alternative explanations, such as two-step kaon-exchange models [10,11], have also been advanced. Since vector-meson production in close-to-threshold pp → ppV reactions must proceed via the spin-triplet entrance channel, the investigation of the cross section ratio σ(pp → ppφ)/σ(pp → ppω) at small excess energies ǫ should provide a clean way of investigating possible violations of the OZI rule.Total cross sections for ω-production in proton-proton collisions have been measured in a range of excess-energy ǫ from a few MeV up to several GeV [12,13,14], whereas data for ppφ are very scarce. Two total cross sections of φ production have been obtained for ǫ ∼ (2 − 4) GeV, but with rather limited accuracy [15,16]. At low excess energy, a single measurement of total and differential cross sections has been made b...

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“…At a beam momentum of 10.0 GeV/c, the φ production cross section is 1.0±0.1 µb [259] in proton-proton interaction. This is to be compared with the antikaon production cross section of 33±16 µb at the same beam momentum [260].…”

Section: Subthreshold Antikaon Productionmentioning

confidence: 97%

Medium effects in high energy heavy-ion collisions

1996

J. Phys. G: Nucl. Part. Phys.

172

193

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The change of hadron properties in dense matter based on various theoretical approaches are reviewed. Incorporating these medium effects in the relativistic transport model, which treats consistently the change of hadron masses and energies in dense matter via the scalar and vector fields, heavy-ion collisions at energies available from SIS/GSI, AGS/BNL, and SPS/CERN are studied. This model is seen to provide satisfactory explanations for the observed enhancement of kaon, antikaon, and antiproton yields as well as soft pions in the transverse direction from the SIS experiments. In the AGS heavy-ion experiments, it can account for the enhanced K + /π + ratio, the difference in the slope parameters of the K + and K − transverse kinetic energy spectra, and the lower apparent temperature of antiprotons than that of protons. This model also provides possible explanations for the observed enhancement of low-mass dileptons, phi mesons, and antilambdas in heavy-ion collisions at SPS energies. Furthermore, the change of hadron properties in hot dense matter leads to new signatures of the quark-gluon plasma to hadronic matter transition in future ultrarelativistic heavy-ion collisions at RHIC/BNL.

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Comparison of ø production by π, K and p incident on protons at 10 GeV

Cited by 31 publications

References 8 publications

Polarization observables in the reactionNN→NNφ

Polarization observables in the reactionNN→NNφ

Near-Threshold Production ofϕMesons inppCollisions

Medium effects in high energy heavy-ion collisions

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