Radiative decay of the Delta resonance: Analyzing powers for pi- p (polarized) ---> gamma n

Stasko, J.C. ; Bassalleck, B. ; Booth, E.C. ; et al.
Phys.Rev.Lett. 72 (1994) 973-976, 1994.
Inspire Record 376202 DOI 10.17182/hepdata.19677

The polarized target asymmetry AN for π−p→→γn has been measured by coincident detection of the γ and the neutron at several angles across the Δ resonace energy region. A high-resolution NaI γ spectrometer together with good time-of-flight information for the neutron resulted in excellent separation of this radiative capture reaction from the much higher cross-section charge exchange reaction π−p→→π0n. Statistical uncertainties are ΔAN=0.02-0.04, representing a significant improvement over previous results. The new data are discussed in the context of recent theoretical models.

1 data table

No description provided.


Measurement of the pi- p ---> n pi0 and pi- p ---> n gamma differential cross-sections near the resonance p(11)(1460)

Cheze, J.B. ; Codreanu, N. ; Hamel, J.L. ; et al.
Nucl.Phys.B 72 (1974) 365-375, 1974.
Inspire Record 94658 DOI 10.17182/hepdata.7810

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.

5 data tables

No description provided.

No description provided.

BACKWARD CROSS SECTION ESTIMATED BY LEGENDRE POLYNOMIAL FIT.

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A measurement of the pion-nucleon charge-exchange reaction pi- p ---> pi0 n at 22.6, 32.9 and 42.6 mev

Duclos, J. ; Gerard, A. ; Magnon, A. ; et al.
Phys.Lett.B 43 (1973) 245-248, 1973.
Inspire Record 84941 DOI 10.17182/hepdata.28155

We have determined the pion charge exchange cross section on hydrogen for π ° mesons emitted at 180° by measuring neutron time-of-flight. Using known values of the p-wave phase shifts we have deduced the contribution of the s-wave. We obtain a value for the quantity a 1 − a 3 (in h = c = m =1 units where m is the pion mass) =0.270±0.014 in agreement within the errors with recent theoretical calculations. We also find a value of 114±55 μb / sr for the cross section in the center of mass system for radiative pion capture at 22.6 MeV (gamma ray emitted at 180°).

1 data table

No description provided.


Differential Cross-Sections for pi- p --> gamma n in the First Resonance Region

Guex, L.H. ; Joseph, C. ; Tran, M.T. ; et al.
Phys.Lett.B 55 (1975) 101-106, 1975.
Inspire Record 90715 DOI 10.17182/hepdata.27879

Differential cross-sections for negative pion radiative capture on protons at c.m. angles of 60°, 90°, and 120° have been measured at nine incident laboratory energies between 110 and 270 MeV. Comparison with measured cross-sections for pion photoproduction and with conventional multipole analyses shows neither evidence for a violation of time reversal invariance nor for an isotensor component of the electromagnetic current of hardrons.

7 data tables

Axis error includes +- 0.0/0.0 contribution (QUOTED ERRORS INCLUDE THE 5 PCT AND 3 PCT UNCERTAINTIES IN THE NEUTRON AND PHOTON DETECTOR EFFICIENCIES).

Axis error includes +- 0.0/0.0 contribution (QUOTED ERRORS INCLUDE THE 5 PCT AND 3 PCT UNCERTAINTIES IN THE NEUTRON AND PHOTON DETECTOR EFFICIENCIES).

Axis error includes +- 0.0/0.0 contribution (QUOTED ERRORS INCLUDE THE 5 PCT AND 3 PCT UNCERTAINTIES IN THE NEUTRON AND PHOTON DETECTOR EFFICIENCIES).

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