G.A. Smith

On the difference between pp and pp topological cross sections up to 100 GeV/c

Abstract New 100 GeV/c p p data are used to find moments of the difference between the p p and pp topological cross sections. The mean multiplicity for annihilations at 100 GeV/c is estimated to be 9.06 ± 0.56, and the value of the quantity 〈n〉/D to be 2.75 ± 0.33. It is shown that R n = {σ n ( p p) − σ n (pp)}/σ n (pp) appears at 100 GeV/c to have acquired an asymptotic form, Rn = s−αβn, with α and β constant.

Charged particle multiplicities in 100 GeV/c p interactions

Abstract Results are presented on the topological cross sections obtained for antiproton-proton interactions from an exposure of the Fermilab 30-inch bubble chamber to a 100 GeV/ c negative beam enriched in p s. The p p inelastic cross section is found to be σ inel = 34.6 ± 0.4 mb, and the average inelastic charged particle multiplicity to be 〈 n 〉 = 6.74 ± 0.05.

Comparison of neutral particle production in 100 GeV/cp̄p and pp interactions

Abstract We derive cross-sections for the inclusive productiion in pp interactions at 100 GeV /c of π 0 , K S 0 and Λ 0 Λ 0 of 91.5±5.7 mb, 5.2±0.4 mb and 4.8±0.4 mb respectively, which are all higher than pp cross-sections at energy. We find indications that these differences can be attributed to “annihilation” processes.

A study of the lifetime and spin of Ω− produced in K−p interactions at 8.25 GeV/c

Abstract Using the decay mode Ω − → Λ K − , we have obtained a measurement of the Ω − lifetime τ Ω = (0.80 ± 0.12 0.16 ) × 10 −10 s . The Ω − decay angular distribution is consistent with W( cos θ ∗ ) ∝ 1 + 3 cos 2 θ ∗ . The probability of consistency with a flat distribution is ∼ 1 300 indicating J ≠ 1 2 .

A partial-wave analysis of the Kππ system produced in the reaction K−p → K0π+π−n at 8.25 GeV/c

Abstract A partial-wave analysis of the K 0 π + π − system from the reaction K − p → K 0 π + π − n has been carried out using data obtained at 8.25 GeV/ c in a high-statistics experiment. A strong signal appears in the 1 + SO + (K ∗ π) wave at the Q 2 mass (≈ 1.4 GeV). The 1 + S0 + (ϱK) wave behaves rather like a background and does not exhibit the characteristics of a resonance. A prominent signal also appears in the 2 + D wave (via K ∗ π and ϱK); it is interpreted as the K ∗ (1430). In the L region (1.6–2.1) GeV, there is evidence for the 3 − K ∗ (1780) while the 2 − wave also gives some contribution. A strong signal shows up in the 1 − P0−(K ∗ π) wave around 1.47 GeV; it does not seem to be due to a resonance. The 0 − S0 + (κπ) wave gives a large contribution in the 1–2 GeV region, but it cannot be identified with the resonating 0 − S 0 + (e K ) or 0 − P 0 + ( K ∗ π) waves observed in diffractive channels.

Production of S = − 2 and −3 baryon states in 6.5 GeV/c K−p interactions

Abstract We present results from a high statistics (46 events/μ;b) experiment on K−p interactions in the Argonne 12 foot bubble chamber. In particular we make a systematic search for Ξ ∗ resonances. We confirm recent evidence of a Ξ(2370), and see a number of other well established states. We also give cross sections for various exclusive and inclusive reactions, including those in which θ− are produced.

Diffraction and resonance production in exclusive pp interactions at 100 GeV/c

Abstract 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 ϱ0 production.

Observation of a KK enhancement at 1.85 GeV in the reaction K−p → KKΛ at 8.25 GeV/c

Abstract In a high statistics ( ∼150 eV μb ) bubble chamber experiment on K − p interactions at 8.25 GeV c , the study of the reaction K − p → KK Λ provides evidence for an enhancement in the KK system with a mass of (1850 ± 10) MeV and a width of (80 −30 +40 ) MeV. Its possible identification with the missing isosinglet of the 3 − nonet is discussed. A K ∗ K decay mode is also observed.

Study of the approach to scaling and factorization in proton fragmentation into π

Abstract From an analysis of previously published data as well as some new results from the Fermilab 30-inch bubble chamber, we study the energy dependence of inclusive π ± production in the target proton fragmentation region. The dependence at high energy is shown to be consistent with an s − 1 2 behavior. Furthermore, both π + and π − data show evidence for Pomeranchuk factorization in the limit of infinite energy.

Inclusive particle production in 100 GeVc π−p and pp interactions

Abstract We discuss a number of features of π − p interactions at 100 GeV/ c , and in particular we attempt to understand the differences between π − p and p p interactions using p p data from the same experiment. The optics considered include the rates of strange particle production, charge transfer distributions, the partition of energy among various particle species and inclusive meson production in beam and target fragmentation regions, with special reference to constituent models of hadrons.