Helicity conservation in the reaction π − p → pA 1 at 4.45 GeV/ c has been studied using 50 cm and 55 cm liquid hydrogen bubble chambers. In the Jackson and the helicity frames the dependence of the ϱ matrix elements on the four-momentum transfer squared to the proton ( t ) for A 1 maximum decay has been calculated. The obtained data are in a good agreement with t -channel helicity conservation. The t -channel dependence of the ϱ matrix elements in the mentioned frames is in good agreement with that calculated using the Regge π-pole exchange model (it is suggested that the A 1 maximum nature is explained by a kinematical effect of the Deck type).
No description provided.
An investigation has been performed of some properties of Σ(1660) produced in the reaction K−p→Σ+(1660)π− at 2.87 GeV/c incident K− momentum. The decay modes observed for this state include Λ(1405)π and Σπ. The spin and parity are measured to be JP=32−. The differential cross section of the Λ(1405)π decay mode is sharply peaked in the forward direction, falling exponentially with a slope of 5.6 ± 0.7 (GeV/c)−2, while the slope for the Σ0π+ decay mode is 2.1 ± 0.4 (GeV/c)−2. The difference in the ratio of backward to total events for the two decay modes also suggests that two Σ(1660)'s exist.
No description provided.
No description provided.
Results are presented for the reactions (1) π+n→pπ+π−, (2) π+n→pπ+π−π0, at an incident pion beam momentum of 11.7 GeV/c. Both reactions show considerable resonance production. Reaction (1) is dominated by ρ0 and f0 production and there is evidence for the variation of the ρ00 width with momentum transfer. Decay angular distributions are presented for the dipion system observed in reaction (1). Reaction (2) shows the production of both dipion and tripion resonances and there is evidence for the associated production of\(\mathcal{N}\)-resonances with the dipion resonances.
No description provided.
DN/DT PLOTTED. ALL RESONANCES ARE DEFINED JUST BY MASS CUTS.
RHO0 MASS REGION OF DIPION SYSTEM. NUMERICAL VALUES TAKEN FROM TABLE 6.1 OF THE THESIS BY D. KEMP (DURHAM 1974).
The two coherent reactions π+d → dπ+π+π− and π+d → → dπ+π+π+π0 are studied in the 2 m DBC at the incoming momentum of 11.7 GeV/c. The production cross-sections are measured:σ=(0.37±±0.06) mb andσ=(0.24±0.05) mb respectively. The two reactions are analysed in the different LPS configurations. The dσ/dt′ distribution for the two reactions displays the same exp[−At′] shape withA⋍37 (GeV/c)−2 in both cases, thus indicating that the differential cross-sections are dominated by the deuteron form factor. The coherent inclastic interaction contains the channel π+d → θ0π+d with a cross-sectionσ==(20±5) µb and a signal for the B+-meson of about 12 µb. The four-pion masses display structures below 2 GeV/c.
No description provided.
No description provided.
Evidence is presented for production of Ξ* resonances, decaying into Ξπ, Ξ(1530)π, ΛK¯, and ΣK¯, in K−p interactions at 2.87 Gev/c. The data represent final combined results from a 30-events/μb hydrogen exposure and an 18-events/μb exposure in deuterium designed to study Ξ* production in the mass interval 1.46-2.07 GeV/c2. In addition to Ξ(1820) and Ξ(1940), signals have been observed at masses of 1630 MeV/c2 and 1860 MeV/c2 decaying into Ξ−π+ and YK¯, respectively. Reaction cross sections have been measured for all final states containing two visible signs of strangeness, and for the final states ΛK−K+ and Σ0K−K+.
CROSS SECTIONS ARISING FROM VARIOUS TOPOLOGIES.
K- P CROSS SECTIONS FROM DEUTERIUM TARGET EXPERIMENT. RESULTS ARE IN GOOD AGREEMENT WITH THE HYDROGEN DATA.
No description provided.
The reactions p¯p→V0+neutrals were studied in a multiparticle spectrometer at 3.0 GeV/c incident momentum, with a sensitivity of about 150 events/μb. Differential cross sections and polarization of the Λ¯ for the final states Λ¯(Λ) and Λ¯(Σ0) are reported and compared with theoretical models. Differential cross sections of the K0 in K0[K*(890)] and the Λ in Λ(Λ¯+Σ¯0) are also measured. Upper limits of a few μb MeV are obtained for the formation of narrow resonances decaying into V0+neutrals in the mass interval 2.74-2.80 GeV/c2.
FORWARD HEMISPHERE TOTAL CROSS SECTIONS NOT INCLUDING CHARGE CONJUGATE REACTIONS. CORRECTED FOR DECAY BRANCHING RATIOS AND FOR BACKGROUNDS.
No description provided.
No description provided.
We observe a K−π+ state at 1786 ± 8 MeV with a width 95 ± 31 MeV in the reaction K−p→K−π+n at 6 GeV/c, from an experiment carried out at the Brookhaven National Laboratory multiparticle spectrometer.
ERROR INCLUDES SYSTEMATIC NORMALIZATION UNCERTAINTY.
Analysis of 5180 ν¯ interactions shows a variation with energy of the inelasticity (y) distributions over the range 10 to 220 GeV and a dependence on the scaling variable x. From these data are obtained the approximate x dependence of the sea quarks and a limit on the strength of right-handed coupling between the u quark and a massive b quark.
No description provided.
None
No description provided.
DIFFRACTION DISSOCIATION EVENTS.
NON-DIFFRACTION EVENTS.
The reaction of tp → pdn in 4π geometry was investigated by exposition of an 80 cm liquid hydrogen bubble chamber to a t-nucleus beam of 2.5 GeV/ c momentum. The main characteristics of the reaction are described reasonably well by the pole approximation in the absolute normalization and without free parameters.
No description provided.
No description provided.
No description provided.