The differential cross section for K ± p elastic scattering has been measured in the very low t region (0.003 < t < 0.2 GeV 2 ) in a wire chamber spectrometer experiment at 10.4 and 14 GeV/ c . The interference effect observed between the Coulomb and the nuclear interaction has been used to determine α, the ratio of real to imaginary part of the forward scattering amplitude. At 10.4 GeV/ c we measure α (K + p) = −0.21 ± 0.06 and α (K − p = 0.08 ± 0.04, and at 14 GeV/ c , α (K + p) = − 0.13 ± 0.03 and α (K − p) = 0.000 ± 0.04 in agreeement with the predictions of dispersion theory calculation.
No description provided.
New data from a 600 000 picture exposure of the BNL 31 inch hydrogen bubble chamber to a separated antiproton beam have been analyzed to try to determine if the π + π − π + π − or π + π − π + π − π 0 final states contribute any broad or narrow structure in the T(2190) region. The resonance channel fractions determined by maximum likelihood fits are all consistent with smooth behavior through the T-region and therefore there is no significant evidence that any of these resonance channels contributes to the broad bump in the total cross section. The errors on some of the fractions, however, limit the sensitivity to ∼ 0.5 mb for enhancements in these channels.
RESONANCE CHANNEL PERCENTAGES FROM FIT TO PI+ PI- PI+ PI- FINAL STATE.
RESONANCE CHANNEL PERCENTAGES FROM FIT TO PI+ PI- PI+ PI- PI0 FINAL STATE.
None
No description provided.
No description provided.
No description provided.
The cross section e + e − → π + π − π o has been measured in the φ energy region and at three other energies (915, 990, 1076 MeV) chosen outside the ω and φ resonances. In the same experiment the energy position and the width of the φ resonance have been determined from the φ →K S o K L o channel. It is found that the magnitude and energy dependence of the experimental cross section are well described by coherent production of ω and φ in the whole energy range 770 to 1076 MeV. Our data clearly show an interference effect which corresponds to an opposite sign between the two products g γω g ω →3 π and g γφ g φ →3 π of the coupling constants.
EXPERIMENTAL CROSS SECTIONS - RADIATIVE CORRECTIONS CAN BE SIGNIFICANT.
The radiative decay models of the φ-meson have been studied: e + e − → φ → ηγ →3 γ ; e + e − → φ → π o γ →3 γ . Cross sections σ φ → ηγ →3 γ and σ φ → π o γ →3 γ have been measured at five energies in the φ-meson energy region and clearly show the φ-resonance in the ηγ → 3 γ mode as well as in the π o γ → 3 γ mode. From a Breit-Wigner fit to the experimental data the values of the branching ratios are deduced: B φ → ηγ = (1.5 ± 0.4) × 10 −2 ; B φ → π o γ = (1.4 ± 0.5) × 10 −3 .
REMOVING RADIATIVE CORRECTIONS, THE PHI PEAK CROSS SECTIONS ARE 66 NB +- 25 PCT <ETA GAMMA> AND 6.5 NB +- 30 PCT <PI0 GAMMA>.
The results of a wire chamber spectrometer experiment studying K ∗ (890) production in the reaction K − p→ K − π + n at 13 GeV are presented. Strong forward structure is observed for | t |< m 2 π in the s -channel density matrix elements and differential cross section. These features are similar to those observed in π − p→ϱ 0 n data and are characteristics of π exchange. In contrast in the intermediate, | t | ∼ 0.2 GeV 2 , and large momentum transfer regions K ∗ (890) production is demonstrated by the natural parity ϱ−A 2 exchange contribution.
No description provided.
Approximately 12 000 examples of the reaction pp→Δ++(1236)n have been identified at 6 GeV / c in a spark-chamber experiment performed at the Argonne National Laboratory Zero Gradient Synchrotron. The experimental invariant-mass and momentum-transfer-squared distributions are in agreement with predictions of the Chew-Low one-pion-exchange model, suitably modified to account for form factors or absorption. The data have been extrapolated from the physical region to the pion pole. It is found that the Dürr-Pilkuhn and Benecke-Dürr models, in conjunction with quadratic extrapolations in t, reproduce the known on-mass-shell dependence of the cross section for the elastic π+p scattering.
No description provided.
No description provided.
The possible existence of new vector mesons above the ρ is investigated. The conclusion is that our data are compatible with the existence of the ρ′-meson only if we assume as a firm theoretical prediction the Gounaris-Sakurai tail of the standard ρ-meson. Furthermore our data are compatible with the existence of the ρ″-meson if we assume the validity of the\(\bar p\)p model for the calculation of the multihadron cross-section.
THESE MEASUREMENTS OF THE PION FORM FACTOR ARE GIVEN IN D. BOLLINI ET AL., NCL 14, 418 (1975).
THESE MEASUREMENTS OF THE FOUR CHARGED PION CROSS SECTION ARE GIVEN IN M. BERNARDINI ET AL., PL 53B, 384 (1974).
THESE MEASUREMENTS OF THE TOTAL HADRONIC CROSS SECTION ARE GIVEN IN M. BERNARDINI ET AL., PL 51B, 200 (1974).
None
No description provided.
The differential cross section for π±, K±, and p± on hydrogen have been measured in the range 0.07<−t<1.6 (GeV/c)2. The dependence on momentum, momentum, transfer, and particle type are discussed.
No description provided.
Forum