Measurements have been made of the total charge-exchange cross section π − p to π 0 n over the laboratory kinetic energy range 90 to 290 MeV. The data have an absolute accuracy of typically 1%, and have here been used to determine the pion-nucleon P 13 phase shift.
No description provided.
No description provided.
The most recent total-cross-section data are used to calculate real parts of the forward elastic π±p scattering amplitudes from threshold to 240 GeV/c. Using statistical and systematic uncertainties of the total cross sections and their momenta, along with uncertainties of the subtraction and coupling constants, unphysical cuts, and cross-section extrapolations, we calculate the uncertainties of the real amplitudes. Our results are compared to experimental and other theoretical determinations of the π±p forward real amplitudes.
No description provided.
No description provided.
No description provided.
A precise measurement of the differential cross section at zero degrees for the pion charge-exchange reaction π−p→π0n at pπ=522 MeV/c has been made. The result is dσdΩ (0∘)=4.32±0.11 mb/sr.
DIFFERENTIAL CROSS SECTION AT THETA = 0.
None
No description provided.
The differential cross section for π − p → n π o has been measured in detail from 150 to 600 MeV. The backward cross section has a previously unobserved dramatic dip at 425 MeV. We interpret this dip in terms of interference between the P 33 (1236) and the P 11 (1470) resonances. These data provide strong evidence for the adequacy of the phase shift solutions in this energy range.
SCALED TO AGREE WITH SOLUTION AT 225 MEV AND THEN INTERPOLATED.
From the Kelly compilation.
From the Kelly compilation.
The forward charge-exchange differential cross section has been measured using two Čerenkov spectrometers at five energies of incident pions. The resulting cross-section values are 4.02 ± 0.22, 3.61 ± 0.13, 4.19 ± 0.13, 3.91 ± 0.12, 3.02 ± 0.14 mb/sr at incident pion energies 400, 450, 500, 550 and 600 MeV, respectively. These values are in a good agreement with dispersion-relation predictions.
No description provided.
The π − p→n γ and π − p→n π ° differential cross sections have been measured for −0.9< cos θ ∗ <−0.45 (θ ∗ c.m. scattering angle) at 475 MeV/ c and 550 MeV/ c incident momenta. The π − p→n γ measurement is a good check of the detailed balance principle in the electromagnetic interactions of hadrons at these energies and is in good agreement with Walker's analysis. On the other hand the π − p→ π °n extrapolated values of 180° allows one to verify that the phases of the A 1 2 and A 3 2 amplitudes are equal.
No description provided.
No description provided.
BACKWARD CROSS SECTION ESTIMATED BY LEGENDRE POLYNOMIAL FIT.
Seventeen differential cross sections of the pion-nucleon charge-exchange reaction have been measured at total center-of-mass energies of 1245, 1337, and 1363 MeV. Most measurements are based on the neutron-photon coincidence method, using carefully calibrated neutron counters and an efficient, large-area photon detector. The results are used to test the predictions of charge independence, with which they agree. The results also confirm the Ayed-Bareyre-Sonderegger phase-degeneracy hypothesis at θ̃π0=180°.
No description provided.
No description provided.
No description provided.
The asymmetry parameter A in π−p elastic scattering at incident pion laboratory kinetic energies Tπ of 98, 238, and 2922 MeV and in π−p charge-exchange scattering π−p→π0n at Tπ=238, 292, and 310 MeV have been measured over a wide range of scattering angles (typically from about 60° to 130° c.m.) with a polarized proton target. The data have been used in an energy-independent phase-shift analysis to improve the precision of the pion-nucleon phase shifts, to set new limits on violation of isospin conservation in the pion-nucleon S wave, and to confirm significant charge dependence in the P32 wave.
Axis error includes +- 0.0/0.0 contribution (?////BACKGROUND SUBTRACTION SMALL).
Axis error includes +- 5/5 contribution (BACKGROUND SUBTRACTION).
Axis error includes +- 5/5 contribution (BACKGROUND SUBTRACTION).
None
No description provided.
Forum