The polarization parameter has been measured for π − p elastic scattering in the backward region at 3.5 GeV/ c incident momentum. The experimental set-up consisted of a polarized target in a spectrometer magnet, hodoscopes and wire spark chambers. Data are presented for the range −0.95< u ⩽−0.19 GeV 2 . An isospin analysis has been carried out to separate the I u = 1 2 and I u = 3 2 contributions.
BACKWARD SCATTERING.
A polarized neutron target was used at the Bonn 2.5 GeV Synchrotron to measure the target asymmetry for the reaction γ n↑→ π − p at a fixed photon energy of 700 MeV and pion c.m. angles between 50° and 140°. The pions were detected in a large aperture magnetic spectrometer. The data show a structure which is quite different from the distribution previously measured for the reaction γ p↑→ π + n.
No description provided.
The reaction π − + p → π − + π − + π + + p at 25 GeV/ c was studied in the mass region M 3 π ⩾ 1.8 GeV with leading π + . The mass spectrum of the π + π − system shows peaks corresponding to the ϱ 0 , f and g 0 resonances and an enhancement around 1.9 GeV. Evidence is presented for a J P = 3 + s-wave g 0 π − state (A 4 ) similar to the ϱ 0 π − (A 1 ) and fπ − (A 3 ) threshold enhancements.
No description provided.
The energy dependence of the modulus and phase of the K L 0 -K S 0 regeneration amplitude on hydrogen in the range of 14–50 GeV has been investigated at the Serpukhov 70 GeV accelerator. It has been established that the modulus of the modified regeneration amplitude decreases with increasing momentum as 2|ƒ 21 0 (p)|/k = (0.84 ± 0.42) · p −0.50±0.15 mb . The amplitude phase is energy-independent and its mean value is ϕ 21 0 = −132° ± 5°. The results obtained are compared with other experiments and with predictions of different theoretical models.
TABLE ALSO CALCULATES FORWARD DIFFERENTIAL CROSS SECTION AND SIG(AK0 P) - SIG(K0 P) TOTAL CROSS SECTION DIFFERENCES.
The production of η(550) and ω(780) mesons is studied in π ± p interactions at 16 GeV/ c and K − p interactions at 10 and 16 GeV/ c . Cross sections for exclusive channels are presented, and for the π + p data differential cross sections are given for quasi-inclusive production where the η or ω is required to be accompanied by charged particles only. Close similarities are observed between η, ω and also ϱ 0 (770) production in terms of longitudinal and transverse variables. By a rough estimate, the η, ω and ϱ 0 inclusive yields are found to be in the ratio 0.32 : 0.85 : 1, respectively, for 16 GeV/ c π + p collisions. For non-peripheral production we estimate this same ratio to be 0.34 : 0.9 : 1.
Axis error includes +- 0.0/0.0 contribution (?////).
Axis error includes +- 0.0/0.0 contribution (?////).
DATA SUPPLIED BY A.A. LEBEDEV.
Results of a Fermilab experiment using the 30-in. hydrogen bubble chamber are reported, with the main emphasis on pion production in the central region. Single-particle inclusive and semi-inclusive distributions in rapidity, Feynman x, and pT2 for both π− and π+ are presented and compared with results of other experiments. Two-particle distributions are investigated using the correlation-function formalism. The relation between inclusive and semi-inclusive correlation functions is discussed. The semi-inclusive correlation functions in rapidity are found to have short-range character compatible with the ideas of independent-cluster-emission models. Evidence for effects due to Bose-Einstein statistics of like particles is found by comparing the joint correlation function in rapidity and azimuthal angle, as well as the charged multiplicity associated with transverse momentum in the like- and unlike-charge combinations. Data on the average associated transverse momentum are also presented. The inclusive and semi-inclusive three-particle distributions are presented for all charge combinations. The inclusive three-particle correlations are found to be small for events with more than four particles in the final state. Two independent ways were found in which three-particle densities can be expressed in terms of one- and two-particle densities.
No description provided.
No description provided.
In a sample of 108 563 pictures taken with the Fermilab 30-inch hydrogen bubble chamber, exposed to a 360-GeV/c π− beam, we have observed 19 453 interactions in a selected fiducial region. The observed charged multiplicity distribution has been corrected for the effects of scan efficiency, errors in prong count, missed close-in vees, secondary interactions, and neutron stars and for Dalitz pairs. The two-prong events have been corrected for losses at low −t. The total cross section is measured to be 25.25 ± 0.35 mb, and the elastic cross section is 3.61 ± 0.11 mb with an exponential slope of (8.82 ± 0.30) (GeV/c)−2. The average charged-particle multiplicity for inelastic events is 8.73 ± 0.04, and the second moment f2 is measured to be 9.83 ± 0.23.
SYSTEMATIC CORRECTIONS INCLUDED IN ERRORS.
FROM FIT, FORWARD D(SIG)/DT = 31.84 +- 0.68 MB/GEV**2, AND AGREES WITH OPTICAL POINT FROM MEASURED TOTAL CROSS SECTIONS.
The reaction e + p → e' + n + π + was studied detecting e' and e' and π + in coincidence at an invariant hadronic mass of 2.19 GeV. The measurements were performed at electron four-momentum transfers squared of Q 2 = 0.06, 0.28, 0.70, and 1.35 GeV 2 in the range of t = ( γ v − π ) 2 between t min and −1.0 GeV 2 . The cross section d 2 σ / dtd was found to be roughly independent of Q 2 for Q 2 > 0.7 GeV 2 and ∥ t ∥ > 0.2 GeV 2 .
No description provided.
No description provided.
No description provided.
None
No description provided.
Differential cross sections for K − n → Σ o π o have been measured at K − momenta between 680 and 840 MeV/ c in a bubble chamber experiment. For K − n → Σ o π − the Σ o polarization was also determined. The measurements were combined with the available data on K − p → Σπ in an energy-dependent partial wave analysis in the center of mass energy range from 1520 to 1745 MeV. An acceptable fit was obtained with the well established resonances.
FULL DETAILS OF THIS EXPERIMENT ARE IN V. HEPP ET AL., NP B115, 82 (1976), THE RECORD OF WHICH CONTAINS THE TABULATED TOTAL AND DIFFERENTIAL CROSS SECTIONS, POLARIZATIONS AND LEGENDRE POLYNOMIAL COEFFICIENTS.
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