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).
Single and joint decay angular distributions in the reaction p p → Δ ++ Δ ++ at 9.13 GeV/ c are discussed in the framework of single and double statistical tensors. The t dependence of 12 double statistical tensors is presented. Cross sections for p p → p p π + π − and p p → Δ ++ Δ ++ are determined to be 2.60 ± 0.10 and 0.90 ± 0.10 mb respectively. The results obtained are compared with other experiments mainly at 5.7 and 12 GeV/ c .
No description provided.
No description provided.
FROM FITTING DECAY ANGULAR DISTRIBUTIONS OF BOTH ISOBARS ADDED.
None
FOUR PION RESONANCE CALLED RHO(1.71) BY AUTHORS. DECAY IS CONSISTENT WITH 100 PCT <RHO0 RHO-> MODE.
We present evidence for δ production in the reactions K − p→ Σ (1385) + δ − ; δ − → η 0 π − , and K − p → Λδ + π − ; δ + → η 0 π + , in a bubble chamber experiment with beam momentum in the range 3.1 to 3.6 GeV/ c . The η 0 from the δ decay is seen both as a missing mass effect, and in its charged decay modes. The δ − has a mass of 989 ± 4 MeV, and width a of 16 −16 +25 MeV (after allowing for experimental resolution). The cross section for Σ(1385) − δ − production is 7±3 μ b; the reaction is produced at small momentum transfers. The mass and width of the δ + are consistent with those of the δ − , and the cross section for the Λ 0 π − δ + final state is about 5 μb. Neither δ appears to be produced as a result of D 0 decay.
No description provided.
We have measured the multiplicities of pions produced in the collisions of π mesons with neon nuclei at bombarding momenta of 10.5 and 200 GeV/c. The diffractive production of pions is clearly separable. If one excludes the diffractive part, the pion multiplicity obeys the same Koba-Nielsen-Olesen scaling as found previously for π−−p collisions. This fact would seem to indicate the validity of an energy-flux or collective-variable description of the production process. A surprisingly large number of energetic protons (> 1 GeV/c lab momentum) are found to be produced in π-Ne collisions.
Elastic and diffractive events removed.
Cross sections, mass spectra, angular distributions and several other features of Ξ − and Ω − production from photons and neutrons in K − d interactions at 4.93 GeV/ c are presented. A five standard deviation peak is observed in Ξ K π mass spectra near 2.6 GeV/ c 2 . A sharp rise in the Ξ − three- and four-body cross sections from K − n interactions suggests direct-channel Σ ∗ (3.0–3.5) formation.
No description provided.
We have done an inclusive study of ϱ 0 production in π − p interactions at 15 GeV/ c . Evidence for two different production mechanisms, in addition to the known quasi two-body processes, is presented: production of ϱ 0 's in the central region of rapidity similar to the “pionization” region seen in the inclusive studies of pions; and forward production in the beam dissociation region of rapidity. Cross sections and rapidity distributions for the ϱ 0 are given inclusively and by topology, and the results are compared with similar studies at other energies and with other incident particles. Results are also presented for the semi-inclusive reaction π − p → p ϱ 0 + X − and the exclusive final state p π − ϱ 0 .
No description provided.
Cross sections are given for the various exclusive reactions K − p→ Λ 0 + n pions, as well as for quasi two-body final states involving ϱ 0 , ω 0 and Y 1 ∗ (1385) resonance production. The general features of Λ 0 production are presented as a function of the pion multiplicity n . Production of Y 1 ∗+ (1385) is clearly observed at all multiplicities while the Y 1 ∗− (1385) signals grow with the multiplicity, as expected in a non-exotic exchange picture. The polarisation of the Λ 0 is consistent with zero everywhere, except when it is a decay product of Y 1 ∗ (1385), when non-zero values are found for odd values of n . The reactions Λ 0 + 2π and Λ 0 + 3π are analysed in terms of the Plahte-Roberts model and good overall agreement is obtained for the various effective mass distributions and the p L ∗ , p T and cos θ distributions for the individual particles.
No description provided.
Results on the channels K − p → Λ 0 η 0 , Λ 0 π 0 , Σ 0 π 0 , Λ 0 π 0 π 0 and Σ 0 π 0 π 0 are obtained in a K − p formation experiment using 1 million photographs taken in a heavy liquid bubble chamber filled with a CF 3 BrC 3 H 8 mixture. The results are compared with hydrogen bubble chamber (HBC) experiments and with experiments having full or partial gamma-ray detection. Our Λ 0 π 0 and Λ 0 + neutral cross section agree with HBC results. Our Σ 0 π 0 cross section does not exhibit a bump at 1670 MeV as previously seen in HBC experiments. Our Λ 0 π 0 π 0 data are dominated by a Σ (1385) π 0 production. Our Σ 0 π 0 π 0 data is consistent with the presence of some Σ (1405) π 0 production.
No description provided.
No description provided.
No description provided.
The reactions K + n → K + π + π − n, K + n → K 0 π + π − p and K + n → K + π − π 0 p have b investigated in a 3.8 event/μb K + d bubble chamber experiment with incident momenta of 2.2, 2.45 and 2.7 GeV/ c . Channel cross sections are given and the general characteristics of the production processes described. The isobar model is used in an attempt to determine the spin-parity structure of the final states.
No description provided.
No description provided.
Forum