A Measurement of the Beam Asymmetry Parameter Sigma for Neutral Pion Photoproduction in the Energy Range 1.2-GeV-2.8-GeV

Bussey, P.J. ; Raine, C. ; Rutherglen, J.G. ; et al.
Nucl.Phys.B 104 (1976) 253-276, 1976.
Inspire Record 100818 DOI 10.17182/hepdata.8492

An experiment has been completed at the Daresbury synchrotron to measure the asymmetry in the photoproduction cross section of neutral pions on hydrogen, for photons polarised normal to and in the production plane. The source of polarised photons was coherent bremsstrahlung of electrons traversing the lattice structure of diamond and the polarisation P of the γ beam was calculated from the measured intensity of the coherent spike. The asymmetry parameter Σ, defined as Σ = ( σ ⊥ − σ |)/( σ ⊥ + σ |) where σ ⊥( σ |) are the cross sections for photons polarised perpendicular (parallel) to the production plane, has been measured over a range of photon energies from 1.2 to 2.8 GeV and over a range of − t (the square of the four-momentum transfer) from 0.13 (GeV/ c ) 2 to 1.4 (GeV/ c ) 2 . A marked energy variation in the value of Σ is found over the energy region 1.6–1.8 GeV.

38 data tables

Axis error includes +- 0.0/0.0 contribution (?////).

Axis error includes +- 0.0/0.0 contribution (?////).

Axis error includes +- 0.0/0.0 contribution (?////).

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ASYMMETRY IN SINGLE pi0 PHOTOPRODUCTION BY POLARIZED gamma RAYS ON PROTONS

Bologna, G. ; Fabbri, F.L. ; Spillantina, P. ; et al.
LNF-70-39, 1970.
Inspire Record 1105046 DOI 10.17182/hepdata.37903

None

1 data table

No description provided.


ASYMMETRY MEASUREMENTS IN PION PHOTOPRODUCTION BY POLARIZED PHOTONS IN THE ENERGY RANGE FROM 250-MeV TO 600-MeV

Antufev, Yu.P. ; Agranovich, V.L. ; Ganenko, V.B. ; et al.
PRINT-70-2307, 1970.
Inspire Record 1105361 DOI 10.17182/hepdata.75432

None

1 data table

No description provided.


Accurate Test of Chiral Dynamics in the \boldmath$\gamma p \rightarrow \pi^0p$ Reaction

The A2 & CB-TAPS collaborations Hornidge, D. ; Aguar Bartolome, P. ; Annand, J.R.M. ; et al.
Phys.Rev.Lett. 111 (2013) 062004, 2013.
Inspire Record 1203736 DOI 10.17182/hepdata.127967

A precision measurement of the differential cross sections $d\sigma/d\Omega$ and the linearly polarized photon asymmetry $\Sigma \equiv (d\sigma_\perp - d\sigma_\parallel) \slash (d\sigma_\perp + d\sigma_\parallel)$ for the $\vec{\gamma} p \rightarrow \pi^0p$ reaction in the near-threshold region has been performed with a tagged photon beam and almost $4\pi$ detector at the Mainz Microtron. The Glasgow-Mainz photon tagging facility along with the Crystal Ball/TAPS multi-photon detector system and a cryogenic liquid hydrogen target were used. These data allowed for a precise determination of the energy dependence of the real parts of the $S$- and all three $P$-wave amplitudes for the first time and provide the most stringent test to date of the predictions of Chiral Perturbation Theory and its energy region of agreement with experiment.

56 data tables

Differential cross section at W=1.0752268 GeV

Differential cross section at W=1.0773190 GeV

Differential cross section at W=1.0793464 GeV

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Angular Dependence of Polarization of Secondary Protons from the Reaction gamma p --> pi0 p at Photon Energies of 650-MeV and 700-MeV

Zybalov, A.A ; Derebchinsky, A.I. ; Konovalov, O.G. ; et al.
Yad.Fiz. 28 (1978) 105-107, 1978.
Inspire Record 135481 DOI 10.17182/hepdata.18990

None

2 data tables

No description provided.

No description provided.


Angular Dependence of the Polarization of the Recoil Proton from the Reaction gamma p --> pi0 p in the Region of the Second Resonance

Blum, P. ; Brinckmann, P. ; Brockmann, R. ; et al.
Z.Phys.A 277 (1976) 311, 1976.
Inspire Record 108242 DOI 10.17182/hepdata.16619

The polarization of the recoil proton from the reactionγp→π0p has been measured for photon energies between 600 and 1,200 MeV and pion c.m. angles between 90° and 150°.

1 data table

No description provided.


Angular Dependence of the Polarization of the Recoil Proton from the Reaction gamma p --> pi0 p in the Region of the Third Resonance

Blum, P. ; Brockmann, R. ; Mohr, W. ;
Z.Phys.A 278 (1976) 275, 1976.
Inspire Record 108304 DOI 10.17182/hepdata.16615

The polarization of the recoil proton from the reactionγp→π0p has been measured for photon energies between 900–1,350 MeV and pion c.m. angles between 70° and 150°. There are significant deviations from recent analysis.

3 data tables

No description provided.

No description provided.

No description provided.


Angular dependence of the recoil proton polarization from the reaction $\gamma p \to \pi^0 p$ for photon energies between 360-MeV and 1200-MeV

Blum, P. ; Brinckmann, P. ; Brockmann, R. ; et al.
BONN-PI-1-105, 1970.
Inspire Record 1085812 DOI 10.17182/hepdata.70500

None

6 data tables

No description provided.

No description provided.

No description provided.

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Angular distributions of the asymmetry of the gamma p ---> p pi0 reaction with the gamma-quanta energies of 400, 450, 500, 550, 650 mev

Ganenko, V.B. ; Gorbenko, V.G. ; Zhebrovskii, Yu.V. ; et al.
Yad.Fiz. 20 (1974) 356-358, 1974.
Inspire Record 95035 DOI 10.17182/hepdata.19140

None

11 data tables

No description provided.

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Asymmetry Measurements for $\pi^0$ and $\pi^+$ Photoproduction by Linearly Polarized $\gamma$ Rays in the Energy Range 400-{MeV} - 900-{MeV}

Zdarko, R.W. ; Dally, E.B. ;
Nuovo Cim.A 10 (1972) 10, 1972.
Inspire Record 74908 DOI 10.17182/hepdata.37786

The asymmetry ratioA = (σ⊥ -σ∥)/(σ⊥ +σ∥) has been measured by means of linearly polarized γ-rays for π0 and π+ photoproduction. For the reaction γ + p → n + π+, measurements were taken for θc.m. = 135° at γ-ray energies ranging from 390 to 909 MeV. For the reaction γ + p → p + π0, measurements were taken for θc.m. = 60° and 90° at γ-ray energies ranging from 426 to 918 Mev.

3 data tables

No description provided.

No description provided.

No description provided.