We have studied the absorption cross section of antiprotons on Al, Cu, and Pb for T=131.6 and 193.6 MeV. These results are compared with predictions of an optical model fitted to antiproton elastic scattering data on these nuclei and are in agreement with these predictions. The cross sections have an exponential dependence on the mass number A with an exponent of approximately 0.61.
No description provided.
We have studied antiproton elastic scattering on Al, Cu, and Pb for two incident momenta: 514 and 633 MeV/c. The angular region covered extends from the forward Coulomb region to approximately 30 deg. The differential cross sections were analyzed using a nonrelativistic optical potential of the Woods-Saxon form, with the imaginary shape taken from electron scattering data. We obtained fits for the strengths of the real and imaginary parts of the potential, (V0, W0), of (51, 116) MeV for Al, (12, 71) MeV for Cu, and (12, 278) MeV for Pb.
No description provided.
None
TYPICAL QUASIELASTIC ANGULAR DISTRIBUTION FOR NUCLEAR TARGET. OTHER DATA ARE IN ASHFORD ET AL (1985-PHYS REV C).
ABSORPTION CROSS SECTIONS.
No description provided.
We have measured the ratio of the real to the imaginary parts of the p¯p forward-scattering amplitude in the incident-momentum range 360 to 650 MeV/c. These results are in good agreement with predictions of the Paris nucleon-antinucleon potential model which include spin-flip effects.
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RESULTS OF FITS TO THE FORWARD-SCATTERING DIFFERENTIAL CROSS SECTIONS ASSUMING THE RATIO OF THE SPIN-FLIP TO NON-SPIN-FLIP PARTS OF THE FORWARD AMPLITUDE IS ZERO.
RESULTS OF FITS TO THE FORWARD-SCATTERING DIFFERENTIAL CROSS SECTIONS ASSUMING THE RATIO OF THE SPIN-FLIP TO NON-SPIN-FLIP PARTS OF THE FORWARD AMPLITUDE IS PARAMATERISED AS 0.3698-0.1384*PLAB(IN GEV).
The interaction between antiprotons and protons has been studied in the range 1910 to 1990 MeV center-of-mass energy in a drift-chamber experiment at the Brookhaven Alternating Gradient Synchrotron. The total cross section has been determined at eleven different incident momenta, and the elastic cross section between 8 and 30 deg in the laboratory has been measured with an energy resolution of about 5 MeV. The cross section for annihilation into charged mesons has also been measured, with the same resolution. There is no evidence in any of these channels for the existence of a narrow resonance.
Data are for total sample with nuclear physics calculation as described in the paper.
Partial elastic cross sections.
Partial annihilation cross sections.
Recent interest in the low-energy kaon-nucleon system has been substantially motivated by the possible existence of an exotic positive-strangeness, isospin-zero baryon resonance. We report here measurements of the cross section and differential cross section for K+n charge-exchange scattering in our exposure of the BNL 30-inch deuterium bubble chamber to a K+ beam at 0.7, 0.8; and 0.9 GeV/c. We compare our results with previous results and with the predictions of a recently published phase-shift analysis.
Axis error includes +- 4.6/4.6 contribution on point 3.
No description provided.
Measurements of the differential cross section for the coherent elastic scattering process K+d→K+d are presented at four momenta from 600 MeV/c to 890 MeV/c for 0.03<|t|<0.25 (GeV/c)2. Comparisons are made with previous work and with predictions from partial-wave analyses.
No description provided.
No description provided.
No description provided.
The first result of the pp2pp experiment at RHIC on elastic scattering of polarized protons at sqrt{s} = 200 GeV is reported here. The exponential slope parameter b of the diffractive peak of the elastic cross section in the t range 0.010 <= |t| <= 0.019 (GeV/c)^2 was measured to be b = 16.3 +- 1.6 (stat.) +- 0.9 (syst.) (GeV/c)^{-2} .
Measured slope of the elastic cross section.
We report on the first measurement of the single spin analyzing power (A_N) at sqrt(s)=200GeV, obtained by the pp2pp experiment using polarized proton beams at the Relativistic Heavy Ion Collider (RHIC). Data points were measured in the four momentum transfer t range 0.01 < |t| < 0.03 (GeV/c)^2. Our result, averaged over the whole t-interval is about one standard deviation above the calculation, which uses interference between electromagnetic spin-flip amplitude and hadronic non-flip amplitude, the source of A_N. The difference could be explained by an additional contribution of a hadronic spin-flip amplitude to A_N.
The single spin analyzing power for 3 T intervals.
We present the first measurements of the double spin asymmetries A_NN and A_SS at sqrt{s}=200 GeV, obtained by the pp2pp experiment using polarized proton beams at the Relativistic Heavy Ion Collider (RHIC). The data were collected in the four momentum transfer t range 0.01<|t|<0.03 (GeV/c)^2. The measured asymmetries, which are consistent with zero, allow us to estimate upper limits on the double helicity-flip amplitudes phi_2 and phi_4 at small t as well as on the difference Delta(sigma_T) between the total cross sections for transversely polarized protons with antiparallel or parallel spin orientations.
Double spin asymmetries.
Double spin asymmetries.
T dependence of the double spin asymmetry ASS3 with statistical errors only.