Gao, S.G.
Photoproduction
Max results
Sort by Reverse order

Showing 4 of 4 results

Pion Pair Production From $\gamma \gamma$ Interactions at {PEP} and the Radiative Width of the F0 Meson

The DELCO collaboration Courau, A. ; Johnson, R.P. ; Sherman, S.S. ; et al.
Phys.Lett.B 147 (1984) 227-231, 1984.
Inspire Record 202552 DOI 10.17182/hepdata.30498

Results are presented of an untagged e + e − → e + e − + π + π − experiment performed at PEP with the DELCO detector. In the invariant-mass range 0.7 ⩽ W ππ < 2.0 GeV/ c 2 , the QED e + e − background is identified and eliminated, and both the π + π − predictions and the μ + μ − and K + K − background substractions are normalized to the measurement of the e e + e − events. The results agree with a simple model of superposition and interference of the f 0 (1270) resonance, produced with helicity 2, with a Born-term continuum. From a fit of the model to the data, the radiative width of the f 0 is determined to be Γ f 0 → γγ = 2.70 ± 0.21 keV.

1 data table match query
Table 1

Data read from graph.


Backward electroproduction of pi0 mesons on protons in the region of nucleon resonances at four momentum transfer squared Q**2 = 1.0-GeV**2.

The JLab Hall A collaboration Laveissiere, G. ; Degrande, N. ; Jaminion, S. ; et al.
Phys.Rev.C 69 (2004) 045203, 2004.
Inspire Record 625669 DOI 10.17182/hepdata.25226

Exclusive electroproduction of pi0 mesons on protons in the backward hemisphere has been studied at Q**2 = 1.0 GeV**2 by detecting protons in the forward direction in coincidence with scattered electrons from the 4 GeV electron beam in Jefferson Lab's Hall A. The data span the range of the total (gamma* p) center-of-mass energy W from the pion production threshold to W = 2.0 GeV. The differential cross sections sigma_T+epsilon*sigma_L, sigma_TL, and sigma_TT were separated from the azimuthal distribution and are presented together with the MAID and SAID parametrizations.

12 data tables match query
Table 1

Cross section SIG(T) + EPSILON*SIG(L) for COS(THETA*) = -0.975.

Table 2

Cross section SIG(T) + EPSILON*SIG(L) for COS(THETA*) = -0.925.

Table 3

Cross section SIG(T) + EPSILON*SIG(L) for COS(THETA*) = -0.875.

More…

POLARIZATION OF RECOIL PROTONS FROM THE REACTION GAMMA P ---> PI0 P IN THE PHOTON ENERGY RANGE 450-MEV - 800-MEV

Bratashevsky, A.S. ; Gorbenko, V.G. ; Derebchinsky, A.I. ; et al.
Nucl.Phys.B 166 (1980) 525-533, 1980.
Inspire Record 157933 DOI 10.17182/hepdata.34552

Measurement of secondary-proton polarization from the reaction γ p → π 0 p have been performed in the proton energy range 500–800 MeV at c.m. pion emission angles 100°, 120°, 140°. The experiment was carried out using an optical spark chamber telescope at the output of the magnetic spectrometer. The obtained experimental data are included in a Walker-type analysis in order to verify the parameters of the resonances P 11 (1470), D 13 (1570) and S 11 (1535). Proton polarization in the reaction γ p → π 0 p was measured for a photon energy of 450 MeV at a c.m. pion emission angle of 105° using photons linearly polarized at 45° to the reaction plane. A liquid hydrogen target in the field of a superconducting magnet was used for the separation of the P x ′ and P z ′ components of the secondary-proton polarization vector.

1 data table match query
Table 1

No description provided.


Proton Polarization in gamma p --> pi0 p Reaction at an Angle of Theta (pi) = 100-Degrees in CMS in the Second pi n Resonance Region

Derebchinsky, A.I. ; Zybalov, A.A ; Konovalov, O.G. ; et al.
Yad.Fiz. 28 (1978) 265-266, 1978.
Inspire Record 135482 DOI 10.17182/hepdata.19013

None

1 data table match query
Table 1

No description provided.