W. Fickinger

A study and comparison of the inclusive reactions π+n → ϱ0X and K−p → K∗0X

Abstract Data are presented on the reactions π + n → ϱ 0 + X and K − p → K ∗0 + X at 6.0 and 7.3 GeV/ c , respectively. Comparisons are made between these two reactions and with other reactions involving inclusive vector meson production at different energies.

Dipion resonant systems produced in 4.5 GeV/c π+d interactions: Saclay-Orsay-Bologna Collaboration

[This paper presents an analysis of the features observed in the neutral mass spectrum of events of this type: π+d - pp neutrals]

Antiproton annihilations in deuterium at rest into two pions: Evidence for pN bound states near threshold

The charged pion spectra in pd→π−π0ps, π−π+ns have been measured. The Doppler broadening of the pion mom entum due to the spectator neutron recoil is at least a factor of two larger than that due to the proton and in disagreement with that expected from the deuteron wave function. This effect and earlier observations on spectators are well described by assuming narrow NN bound states near threshold.

Study of the reaction π+n→ωp at 6.0 GeV/c

Abstract An analysis of the reaction π + n→ ω p in a 6.0 GeV/ c bubble chamber experiment is presented. The production differential cross section and spin density matrix elements are compared with Regge exchange models.

A study of inclusive vector meson production

Abstract Data are presented on the reactions π + n → ϱ 0 +X and K − p → K ∗ 0 (890)+ X at 6.0 and 7.3 GeV /c , respectively. Comparisons are made with related reactions at higher energies.

["Measurement of the Λ→n+γ branching ratio"]

The branching ratio for the {Lambda} weak radiative decay has been measured to be {ital B}({Lambda}{r arrow}{ital n}+{gamma})/({Lambda}{r arrow}anything) =(1.78{plus minus}0.24(stat){plus minus}{sub 0.16}{sup 0.14}(syst)){times}10{sup {minus}3}. A low-energy kaon beam was used to produce the {Lambda} hyperons via the reaction {ital K}{sup {minus}}+{ital p}{r arrow}{Lambda}+{pi}{sup 0} at rest. Photons from the signal channel and {pi}{sup 0} decay were detected with a NaI(Tl) array. The final spectrum contains 287 events after background subtraction, an order of magnitude more events than from the only previous measurement.

Λ and K0 production in p↑p interactions at 6 GeV/c

Results on K0 and Λ production in p↑p interactions at 6 GeV are presented. The data are from an exposure of the Argonne 12 ft bubble chamber to a 60% transversely polarized proton beam. Results include data on Λ and K0 inclusive production, and on the reactions p↑p → pΛK+(pΣ0K+). The beam asymmetry parameter for p↑p → K0(K0) + X is determined to be (−0.52 ± 0.12).

Backward production of ϱ0 and f0 mesons in π+n interactions at 6 GeV/c

Abstract Backward production of ϱ 0 and f 0 mesons in π + n interactions at 6 GeV/ c is presented. Total and differential cross sections are reported along with spin density matrix elements.

Measurement of the. Lambda. r arrow n +. gamma. branching ratio

The branching ratio for the {Lambda} weak radiative decay has been measured to be {ital B}({Lambda}{r arrow}{ital n}+{gamma})/({Lambda}{r arrow}anything) =(1.78{plus minus}0.24(stat){plus minus}{sub 0.16}{sup 0.14}(syst)){times}10{sup {minus}3}. A low-energy kaon beam was used to produce the {Lambda} hyperons via the reaction {ital K}{sup {minus}}+{ital p}{r arrow}{Lambda}+{pi}{sup 0} at rest. Photons from the signal channel and {pi}{sup 0} decay were detected with a NaI(Tl) array. The final spectrum contains 287 events after background subtraction, an order of magnitude more events than from the only previous measurement.

π − p → π 0 π 0 n near threshold and chiral symmetry breaking

Total cross sections, angular, and mass distributions for the reaction {pi}{sup {minus}}{ital p}{r arrow}{pi}{sup 0}{pi}{sup 0}{ital n} have been measured for {ital p}{sub {pi}}{sup {minus}}(lab)=7--140 MeV/{ital c} above threshold. The threshold amplitude was used to determine a value for the chiral-symmetry-breaking parameter, {xi}, of {minus}0.98{plus minus}0.52. The {pi}{pi} scattering lengths {ital a}{sub {ital I}} for isospin {ital I}=0 and 2 are derived from this result, together with a current-algebra sum rule. The results are {ital a}{sub 0}=(0.207{plus minus}0.028){ital m}{sub {pi}}{sup {minus}1} and {ital a}{sub 2}=({minus}0.022{plus minus}0.011){ital m}{sub {pi}}{sup {minus}1}. These values are consistent with chiral symmetry broken by the Weinberg {pi}{pi} interaction and the effects of the {ital f}{sub 0}(975) scalar meson.