The folded differential cross sections dσdΩ(θ*)+dσdΩ(π−θ*), where θ* is the center-of-mass angle of the negatively charged outgoing particle, have been measured for the reactions p¯p→π−π+ and K−K+ at 15 incident beam momenta between 360 and 760 MeV/c with much better statistics than previous experiments. The total cross sections for these reactions, σπ−π+ and σκ−κ+, have also been obtained by integrating the folded differential cross sections. The folded differential cross sections of both reactions show a similar behavior at all measured beam momenta, characterized by a prominent peak at |cosθ*|=1. The cross section σπ−π+ shows a smooth but rapidly decreasing behavior as the beam momentum increases up to 550 MeV/c, whereas σκ−κ+ shows a smooth and flat momentum dependence. These results are compared with some theoretical calculations based on nonrelativistic quark models. Although the shape of the folded differential cross section of the p¯p→π−π+ reaction is rather well reproduced by these models, that of the p¯p→K−K+ reaction, and, in particular, the prominent peak at |cosθ*|=1 cannot be explained at all. The information from other experiments indicates that this discrepancy is most pronounced at the backward angles. Moreover, the momentum dependence of both σπ−π+ and σκ−κ+ is not satisfactorily reproduced by these models.
Folded differential cross sections.
Folded differential cross sections.
Folded differential cross sections.
The differential cross sections of p¯p elastic scattering have been measured at incident beam momenta of 390, 490, 590, 690, and 780 MeV/c. The results are compared with the predictions of various N¯N potential models. None of these models completely explains the present results.
No description provided.
Legendre expansion coefficients.
This paper presents the results of a study of the dominant neutral final states from π−p interactions. The data were obtained in an experiment performed at the Brookhaven National Laboratory Alternating Gradient Synchrotron, using a set of steel-plate optical spark chambers surrounding a liquid-hydrogen target. We present differential and total cross sections for the reactions (1) π−p→n+π0 and (2) π−p→n+η0(η0→2γ) and total cross sections for the reactions (3) π−p→n+kπ0 (k=2, 3, 4, and 5) and (4) π−p→all neutrals for eighteen values of beam momentum in the interval 1.3 to 4.0 GeV/c. The angular distributions for (1) and (2) have been analyzed in terms of expansions in Legendre polynomials, the coefficients for which are also given.
No description provided.
SIG = 4*PI*LEG(L=0).
FORWARD DIFFERENTIAL CROSS SECTION CALCULATED FROM LEGENDRE POLYNOMIAL COEFFICIENTS AND ERROR MATRICES.
Differential cross sections for the reaction π − p→ η n at 20 incident pion momenta between 724 and 2723 MeV/ c are presented. The results are compared with previous measurements. The data show clear evidence of non-zero couplings of this channel to known I = 1 2 , S = 0 baryon resonances with masses up to 2000 MeV/ c 2 .
No description provided.
No description provided.
No description provided.
An experiment is described to measure the differential cross section for the charge-exchange reaction K 0 p → K + n from 0.6 to 1.5 GeV/ c incident kaon momentum in the angular range −0.65 < cos θ ∗ < 0.85 The calibration of the kaon beam by observation of K S 0 regeneration is also described. The differential cross sections are fitted with Legendre polynomials and compared with those from the time-reversed reaction using deuterium targets. Qualitative conclusions are drawn on the behaviour of particular charge-exchange amplitudes.
No description provided.
FITTED VALUES OF DIFFERENTIAL CROSS SECTION LEGENDRE COEFFICIENTS (4 TIMES USUAL DEFINITION).
New bubble chamber data on the reactions K − n → π 0 Σ 0 in the c.m. energy range 1750–2200 MeV are presented and are compared with the predictions of the most recent partial-wave analysis of the reaction K N → πΣ . The comparison stresses the need for data involving a single value of isotopic spin in the study of this reaction. An analysis of the new data yields two satisfactory solutions involving only well established resonances.
No description provided.
FERMI MOTION OF NEUTRON USED TO EXTRACT ENERGY DEPENDENCE.
NORMALIZED LEGENDRE COEFFICIENTS OF CROSS SECTION ANGULAR DISTRIBUTION.
Results are presented of differential cross-section measurements for the reaction π − p→ π 0 n; π 0 → γγ at 22 incident pion momenta between 618 and 2724 MeV/ c . The results are in good agreement with those of other experiments. They represent the first comprehensive set of high statistics measurements of the π − p charge-exchange differential cross section at closely spaced momenta in the resonance region.
No description provided.
No description provided.
No description provided.
Measurements have been made of the differential cross section for p p elastic scattering over a c.m. angular range −0.95 ⩽ cos θ ∗ ⩽ 0.93 at 21 incident antiproton momenta between 0.69 GeV/ c and 2.43 GeV/ c (c.m. energy 1.96–2.58 GeV). About 10 5 events were obtained at each momentum. The results are discussed primarily in terms of the formation of s -channel resonances in the T and U mass regions, and within the context of the optical model of Frahn and Venter.
No description provided.
No description provided.
No description provided.
Cross sections of the reaction K − p → π + π − π 0 Λ are determined in a bubble chamber study at 10 incoming beam momenta between 1.425 GeV/ c and 1.800 GeV/ c . For the subsample K − p → ωΛ , cross sections and angular distributions are presented together with their Legendre polynomial expansions and those of the single and joint density matrix elements. An energy dependent partial-wave analysis is performed including earlier data. The data is well fitted by constant background amplitudes in the outgoing S, P and D waves plus two I = 0 resonances in this region, the well established G 7 Λ(2100) and the P 3 Λ(1870).
No description provided.
No description provided.
LEGENDRE POLYNOMIAL EXPANSION COEFFICIENTS OF D(SIG)/DOMEGA.
We report here the results from an experiment to obtain differential cross sections for K−p elastic scattering in the laboratory momentum region from 1.4 to 1.9 GeV/c. These data span the region of a bump in the K−p total cross section at an energy of 2.05 GeV. Approximately 20000 elastic events were obtained at each of four momenta with an angular coverage of 0.9≥cosθc.m.≥−0.9. The data are intended to aid in phase-shift analyses of the resonances causing the bump in the total cross section and to study dip structures at constant values of the Mandelstam variables t and u.
No description provided.
LEGENDRE POLYNOMIAL COEFFICIENTS.
FROM INTEGRATING LEGENDRE POLYNOMIAL FIT TO D(SIG)/DOMEGA. QUOTED ERRORS INCLUDE NORMALIZATION AND FITTING UNCERTAINTIES.
Forum