We present final results on the inclusive production of the\(\bar K^{*0} (890)\),K*−(890),K*0(890),K*−(890),K*−(1420), and\(\bar K^{*0} (1420)\) resonances inK−p interactions at 32 GeV/c. Total cross sections and invariantx-distributions are determined. Inclusive cross sections of\(\bar K^{*\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{o} } (890)\) amount to ≃4 mb each, of\(\bar K^{*\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{o} } (1420)\) to ≃1 mb and ofK*0(890) to ≃0.8 mb. These values are in agreement with additive quark model predictions. All strangenessS=−1 resonances are predominantly produced in the forward hemisphere, the tensor mesons being more peripherally produced than the vector ones. The\(\bar K^{*\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{o} } (890)\) density matrix elements andt-distributions are obtained. The unnatural spin-parity exchange contribution to inclusive\(\bar K^{*\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{o} } (890)\) production amounts to ≳60% at |t|<0.4 GeV2 and decreases with increasing |t|. Whenever relevant, a comparison is also made with available data at other energies.
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Results are presented on two-particle inclusive production inK+p interactions at 32 GeV/c. We study thex1,2=x1+x2 dependence of invariant structure functions of (ππ)-pairs and compare them to single particle inclusive distributions in the fragmentation regions. Distributions of particles observed at Feynmanx2 in association with various “trigger” particles or systems atx1 in the same hemisphere are dicussed in terms of the reduced variable\(\tilde x_2= x_2 /(1 - |x_1 |)\). We further present absolute production rates and production ratios of π+'s and π−'s associated with π±,Ks0, Λ,\(\bar \Lambda \),K*+ (890), (Ks0π+), and (π+ π−)-triggers, and compare them with qualitative predictions of the quark recombination model. Forwardbackward correlations between (Ks0π±), (Ks0,p), (Λ, π−),\((\bar \Lambda \pi ^ \pm)\), and (p, π−) pairs are also discussed.
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In a K − p experiment at 32 GeV/ c with a sensitivity of 6 ev/≈b the inclusive reaction K − p → p + X was studied in the kinematical region x < −0.3. Most of the protons in this region were identified by ionization. Correcting for losses of the very slow as well as of the fast protons in this region we obtained σ p ( x < −0.3) = 5.9 ± 0.2 mb. The double invariant differential cross sections of protons were analysed in terms of the variables x , p T 2 , and M 2 / s , t , and the contributions from separate peripheral mechanisms were analysed. A triple-Regge analysis was performed on the inclusive proton d 2 σ /d t d( M 2 / s ) distribution with | t | < 1.1 GeV 2 . The fit with an RRP term resulted in an effective trajectory for the exchanged reggeon lying somewhat lower than that for the leading meson trajectory. Inclusion in the fit of an additional ππp term showed that pion exchange is important in the triple-Regge region at small | t |.
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The cross sections of several exclusive reactions in p p interactions are given. In the channels p p → p p π + π − and p p → p p 2π + 2π − which dominate the interactions, the single and double diffractive dissociations are analysed and compared to the results obtained with K ± p interactions at the same energy, pp and p p interactions at other energies. The test of factorization at the p → p π + π − vertex is well verified. The process p p → Δ ++ Δ ++ is studied and the cross sections of Δ ++ , Δ ++ , ϱ 0 and f 0 production are also given.
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Lambda production is studied in K − p interactions at 32 GeV/ c . The total Λ cross section is 2.31±0.03 mb . Using the measured Λγ combinations we find that (31±4)% of all Λ's are produced via the Σ 0 → Λγ decay. About 60% of the Λ's are associated with either a N N or K K pair; about 40% of the Λ's are produced through the hypercharge annihiltion reaction K − p→ Λ + π 'a. The two-peak structure of the invariant x distribution can be related to fragmentation processes. The Λ is found to be unpolarized in the target fragmentation region, whereas a transverse polarization is observed for forward produced Λ's. As a function of p ⊥, a polarization effect is measured at medium p ⊥.
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We present the first evidence for K ∗ (1780) production in a non-exchange channel. This comes from a study of the reaction K − p → K° π − p at 14.3 GeV/ c . We also present evidence for K ∗ ° (1780) production in the charge exchange channel K − p → K − π + n. No significant K ππ , K ω and K η decay modes are found. The decay angular distribution, the spin-parity assignments and the production mechanism are discussed. With plausible assumptions on the production mechanism, the J P = 3 − spin-parity is favoured.
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We have studied the reactions K − p → K − π + π − p and K − p → K 0 π − π 0 p at 14.3 GeV/ c using respectively 15 992 and 3723 events. Partial-wave analysis of the region 1.0 < m (K ππ ) < 1.7 GeV have been made using a modified version of the method developed at the University of Illinois.
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Inclusive production of vector and tensor mesons is studied in a K − p experiment at 32 GeV/ c in the MIRABELLE bubble chamber. The K ∗ 0 (890) , ϱ 0 and ω cross sections are comparable, about 4 mb each. The K ∗ 0 (1420 and cross sections are also comparable, about 1 mb each. The K ∗ o ̈ + (890), Φ, K ∗ o ̈ − (1420) and f cross sections beam fragmentation; ϱ production is almost forward-backward symmetric in the c.m.s. The p T production slopes of K ∗ o ̈ − (890) and ϱ are similar, the Φ slope is shallower. Vector and tensor mesons alone are responsible for ≅50% (≅60%) of final-state pions
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We present results on a number of non-diffractive two-body channels contributing to reactions K + p→K 0 π + p and K + p→K + π − π + p. The data come from an exposure of the Mirabelle bubble chamber to an r.f. separated K + beam of 32 GeV/ c at the Serpukhov accelerator. Total cross sections are given for the final states K ∗+ (890) p , K ∗+ (1420) p , K 0 Δ ++ (1232), K ∗+ (890) p , Δ ++ (1232), K ∗0 (1420) Δ ++ (1232), K ∗0 (1780) Δ ++ (1232) and K ∗0 (890) Δ ++ (1950) . The differential cross sections are given for all channels with sufficient statistics. The energy dependence of the total and differential cross sections is studied.
FROM K0 P PI+ FINAL STATE.
DOUBLE RESONANCE CHANNEL CROSS SECTIONS CORRECTED FOR BACKGROUND, BREIT-WIGNER TAILS AND DIFFRACTIVE PROCESSES.
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DISTRIBUTION IS PRESENTED IN THE BEAM FRAGMENTATION REGIONS.
DISTRIBUTION IS PRESENTED IN THE BEAM FRAGMENTATION REGIONS.
DISTRIBUTION IS PRESENTED IN THE BEAM FRAGMENTATION REGIONS.
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