Simple inclusive cross sections for p p interactions at 12 GeV/ c are given. The data cover prong cross sections, V 0 production and resonances. Separation has been made into annihilation and non-annihilation modes. Some implications of the data are discussed. It is pointed out that the ratios of cross sections for ϱ 0 π − production are independent of incident antiproton momentum in p p annihilation processes, and that data at the highest available pp energies (ISR) tend to the same value.
NORMALIZED TO A TOTAL CROSS SECTION OF 51.7 +- 0.8 MB.
Three narrow resonances have been observed in e+e− annihilation into hadrons at total energies between 9.4 and 10.4 GeV. Measurements of mass spacing and ratios of lepton pair widths support the interpretation of these "ϒ" states as the lowest triplet-S levels of the bb¯ quark-antiquark system.
No description provided.
The production of K S 0 , Λ and Λ in π − p ractions at 16 GeV/ c is investigated. Cross sections for single strange particles are determined, both inclusively and as functions of the charged multiplicity. Some characteristics of the multiplicity distributions are also discussed. Inclusive distributions are studied as a function of the longitudinal and transverse variables of V 0 and the missing mass squared. The average charged multiplicities of the systems recoiling against the Λ and K S 0 are presented.
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We present results on an amplitude analysis of the K + K − system produced in the reaction π − p→K + K − n from threshold up to 2.2 GeV. The branching ratios of f 0 and f' to K K have been determined. In the low mass region of the K K system the observation of an S-wave enhancement at 1.3 GeV and the interference of the f 0 -A 2 -f' mesons are studied. We observe a 3 − structure in the mass region of 1.7 GeV which is consistent with g 0 production. With this interpretation the branching ratio g→ K K has been determined. Evidence for a new structure in the J p = 2 + wave around 1.8 GeV with a width of ∼200 MeV is presented.
HELICITY ZERO D-WAVE AMPLITUDE FITTED BY SUM OF BREIT-WIGNER RESONANCES. F 14 GIVES T-DEPENDENCE. ALSO EVIDENCE FOR 1.8 GEV STATE WITH 0.60 +- 0.13 MUB PRODUCTION CROSS SECTION.
FROM HELICITY ZERO F-WAVE AMPLITUDE ASSUMING PREDOMINANTLY G(1680)0 PRODUCTION. F 16 GIVES T-DEPENDENCE.
In a high statistics (90 events/μb) bubble chamber experiment, the reactions π − p→K s 0 K ± π ∓ n have been studied at 3.95 GeV/ c . A significant enhancement is observed in the ( K K π) system which we attribute to the production of the E(1420) meson. For its mass, M , and width, Λ, we find M =1426±6 MeV and Γ =40±15 MeV. The E(1420) quantum numbers are determined to be I G J P =0 + 1 + with a branching ratio E → K ∗ K + c.c E →[δπ+( K ∗ K + c.c. )]=0.86±0.12 , where δ→ K K . The cross section for the reaction π − p→En, with E→K 0 K ± π ± , is 8.2±1.0 μ b. Forward and backward productions are observed in the approximate ratio 2:1. The SU(3) assignment of the E(1420) meson is discussed.
BACKGROUND SUBTRACTED.
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K ∗0 (890) production in the hyperchange exchange reaction π − p → K ∗0 (890) Λ 0 Σ 0 at 10 GeV/ c (28 448 events) is discussed. An amplitude analysis in the t ′ range up to 1 GeV 2 shows that the production mechanism is dominated by natural parity exchange (∼84%). Comparisons are made with predictions from a Regge model and a quark model.
DENSITY MATRIX ELEMENTS IN THE GOTTFRIED-JACKSON SYSTEM ALLOWING FOR COHERENT S-WAVE BACKGROUND TO P-WAVE BREIT-WIGNER K*(892)0 RESONANCE.
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A dipion enhancement of mass 1.59 GeV and width 0.23 GeV is observed in the channel γp→π + π − p. The spin-parity of the enhancement is consistent with being 1 − .
No description provided.
We have performed a search for narrow resonances in the center of mass energy range from 29.90 to 31.46 GeV using the e + e − storage ring PETRA at DESY. We present the total cross section for hadron production and an upper limit for resonance production, indicating that no bound state of charge- 2 3 quarks exists in this energy range.
AVERAGE VALUE OF R OVER THE SCAN REGION.
THESE MEASUREMENTS COMBINED WITH PREVIOUS DATA AT 30.0 AND 31.6 GEV REPORTED IN CH. BERGER ET AL., PL 86B, 413 (1979).
A search for narrow resonances in e + e − annihilation at c.m. energies between 29.90 and 31.46 GeV provides no evidence for the existence of such states. The 90% confidence upper limit on the integrated resonance cross section is 38 nb MeV, significantly below the value expected for the lowest (t,t̄) bound state.
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POSSIBLE EVIDENCE FOR OMEGA(1670) RESONANCE.
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