The inclusive production of K̄ ∗ (890) and K̄ ∗ (1420) is studied in K̄ − p interactions at 10 and 16 GeV/ c . At 10 GeV/ c an enhancement in the ( K ̄ 0 π − ) mass distribution is found at 1.74 GeV, but no clear signal is seen at 16 GeV/ c . The fraction of K 0 ' s coming from decay of the K ∗ (890) or K ∗ (1420) is large, being (50 ± 6)% and (45 ± 5)% at 10 and 16 GeV/ c , respectively. The inclusive cross sections for K ∗− (890) and K ∗0 (890) production are almost constant with energy from 8 to 32 GeV/ c with values of 3.5 and 3.3 mb, respectively. The K ∗ (890) production cross section is studied as a function of transverse and longitudinal variables and found to derive mainly from fragmentation of the incident K − meson. The spectra of K 0 ' s resulting from the decay of K ∗ (890) are studied.
No description provided.
No description provided.
No description provided.
We present a systematic analysis of the production of K ∗+ (892) and Δ ++ (1236) resonances in the K + p → K 0 p π + reaction at 5, 8.25 and 16 GeV/ c . We have measured total cross sections, differential cross sections, density matrix elements and examined resonance production mechanisms in terms of the exchange of states with definite naturality. Some results on the reaction K + p → K ∗+ (1420) p are also given.
No description provided.
No description provided.
No description provided.
Inclusive production of Λ and Λ in K + p interactions is studied at incident momenta of 8.2 and 16.0 GeV/ c . Cross sections and single-particle distributions are presented, the correlation between longitudinal and transverse momentum is investigated, and the dependence of average charge multiplicity on missing mass measured. For Λ production, early scaling is observed in the target fragmentation region when the data are presented in terms of ( M 2 - M th 2 )/ s and t , where M th is the threshold value of the missing mass M . Furthermore, a triple-Regge analysis in these variable yields an effective exchange trajectory which passes through the K, Q and L mesons. There is evidence for beam fragmentation in Λ and Λ production, but the contributions seem not to be dominant in the fragmentation region. Nevertheless, the parameter values in a triple-Regge description are estimated, and together with those for target fragmentation in Λ production, provide a complete description of the fragmentation contributions to the two reactions. Integration of the resultant distribution functions over the complete Chew-Low plot yields fragmentation cross sections increasing approximately as log s ; in addition the observed features of the x , p L and p T 2 projections and of the p L - p T correlation are well-described in the fragmentation regions. Central production contributions are isolated by subtracting the calculated fragmentation distributions
No description provided.
No description provided.
No description provided.
The differential cross sections for neutron-proton charge-exchange scattering have been measured with high statistics in the region of momentum transfer squared 0.002 < | t | ⩽ 0.400 (GeV/ c ) 2 and for incident neutron momenta 9 < p ⩽ 23 GeV/ c .
No description provided.
The production of ρ 0 (770) and f(1270) is studied in π − p interactions at 16 GeV/ c . By comparison with inclusive K ∗0 production in the reaction K − p → K ∗0 + anything, and with inclusive ρ 0 production in the reaction pp → ρ 0 + anything, it is found that the data can be interpreted in terms of two production processes: the central production of resonances and the fragmentation of the beam particle. For the π − p reaction, the inclusive ρ 0 beam fragmentation cross section is 3.1 ± 0.3 mb while that for central production is 1.6 ± 0.5 mb. The ρ 0 central production cross section is consistent with increasing with energy as ln s behaviour. The ratio of ρ 0 to π − inclusive cross sections (excluding the leading π − ) is ∼0.2, independent of energy. The ρ 0 to π − ratio increases as a function of p T to a constant value of ∼ 1 2 above 1 GeV/ c . The ρ (charged and neutral) and f decays account for (25 ± 4)% and (1.4 ± 0.3)%, respectively, of all pions produced.
No description provided.
No description provided.
No description provided.
None
No description provided.
No description provided.
The reaction π + p→ ωΔ ++ (1236) is studied at 16 GeV/ c . Cross section, differential cross section, single and joint spin-density matrix elements are given and the correlations between the ε and Δ ++ (1236) decay angular distributions are investigated. Natural and unnatural spin-parity exchanges contribute to this reaction in roughly equal amounts. Natural exchanges lead predominantly to Δ ++ (1236) with helicity ± 3 2 , while unnatural exchanges lead predominantly to Δ ++ (1236) with helicity ± 1 2 and to ε with helicity zero. Furthermore, unnatural exchanges are small at t ′≅0.2 GeV 2 compared to other t ′ values, which may be due to the nonsense wrong-signature-zero of the B-meson exchange. Quark model relations are found to be satisfied by the data.
CORRECTED FOR UNSEEN OMEGA DECAY MODES. 'SLICE METHOD' USED TO HANDLE RESONANCE TAILS AND BACKGROUND.
FROM EVENTS WITHIN MASS-CUTS FOR RESONANCES AND NORMALIZED TO TOTAL CROSS SECTION.
'ALL'.
The reaction π + p → ϱ 0 Δ ++ (1236) at 16 GeV/ c has been studied. Cross section, differential cross section, single and joint spin-density matrix elements are given. Correlations between the ϱ 0 and Δ ++ (1236) decay distributions are observed. Unnatural spin-parity exchanges, mainly observed at small t ' values, dominate the ϱ 0 Δ ++ (1236) production. The natural exchange contributions are only (7 ± 2)% and become as important as the unnatural exchanges beyond t ' = 0.3 GeV 2 . Contributions to Δ ++ (1236) helicity 3 2 states do not exceed 20% of the total ϱ 0 Δ ++ (1236) cross section and are mainly due to unnatural exchanges.
'SLICE METHOD' USED TO HANDLE RESONANCE TAILS AND BACKGROUND.
FROM EVENTS WITHIN MASS-CUTS FOR RESONANCES AND NORMALIZED TO TOTAL CROSS SECTION.
'B'.
The reaction K + p→ Δ ++ (1236)+ anything is studied at beam momenta 8.2 and 16 GeV/ c and compared with other Δ ++ producing reactions. We find that the low-mass Δ ++ π − enhancement affects the shapes of Δ ++ inclusive distributions. The triple-Regge formula is found to be consistent with the data. Dual properties of this formula are successfully tested.
No description provided.
No description provided.
No description provided.
The inclusive cross sections for π − , π 0 , π + and η production in K − p interactions at 14.3 GeV/ c are calculated. The invariant cross section distributions are presented and compared in the whole phase space for π + and π 0 , and in the backward c.m. region for π − . In the fragmentation regions, the charged pion production is analysed in terms of the triple-Regge model.
No description provided.
No description provided.
No description provided.
Forum