Goshaw, A.T.
nucl-ex
Exclusive
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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
dcs01

Differential cross section at W=1.0752268 GeV

dcs02

Differential cross section at W=1.0773190 GeV

dcs03

Differential cross section at W=1.0793464 GeV

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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
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.

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Measurements of the Deuteron and Proton Magnetic Form-factors at Large Momentum Transfers

Bosted, Peter E. ; Katramatou, A.T. ; Arnold, R.G. ; et al.
Phys.Rev.C 42 (1990) 38-64, 1990.
Inspire Record 283632 DOI 10.17182/hepdata.26165

Measurements of the deuteron elastic magnetic structure function B(Q2) are reported at squared four-momentum transfer values 1.20≤Q2≤2.77 (GeV/c)2. Also reported are values for the proton magnetic form factor GMp(Q2) at 11 Q2 values between 0.49 and 1.75 (GeV/c)2. The data were obtained using an electron beam of 0.5 to 1.3 GeV. Electrons backscattered near 180° were detected in coincidence with deuterons or protons recoiling near 0° in a large solid-angle double-arm spectrometer system. The data for B(Q2) are found to decrease rapidly from Q2=1.2 to 2 (GeV/c)2, and then rise to a secondary maximum around Q2=2.5 (GeV/c)2. Reasonable agreement is found with several different models, including those in the relativistic impulse approximation, nonrelativistic calculations that include meson-exchange currents, isobar configurations, and six-quark configurations, and one calculation based on the Skyrme model. All calculations are very sensitive to the choice of deuteron wave function and nucleon form factor parametrization. The data for GMp(Q2) are in good agreement with the empirical dipole fit.

2 data tables
Table 1

The measured cross section have been devided by those obtained using the dipole form for the proton form factors: G_E=1/(1+Q2/0.71)**2, G_E(Q2)=G_M(Q2)/mu,where Q2 in GeV2, mu=2.79.

Table 2

Axis error includes +- 0.0/0.0 contribution (?////Errors given are the statistical errors and systematic uncertainties add ed in quadreture).


HADRONIC PHOTOABSORPTION AND THE COHERENT PHOTOPRODUCTION OF PI0 MESONS ON BE AND C NUCLEI IN THE RESONANCE ENERGY REGION. (IN RUSSIAN)

Ananikian, A.K. ; Arakelian, E.A. ; Bayatian, G.L. ; et al.
Yad.Fiz. 46 (1987) 401-403, 1987.
Inspire Record 255687 DOI 10.17182/hepdata.17423

None

2 data tables
Table 1

No description provided.

Table 2

No description provided.


TOTAL CROSS-SECTION OF PI0 MESON AND HADRON PHOTOPRODUCTION ON Be, C, O, AND Al NUCLEI IN THE ENERGY RANGE E (GAMMA) = 200-MEV - 900-MEV. (IN RUSSIAN)

Arakelian, E.A. ; Bayatian, G.L. ; Vartanian, G.S. ; et al.
Yad.Fiz. 42 (1985) 3-7, 1985.
Inspire Record 227726 DOI 10.17182/hepdata.17616

None

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


TOTAL CROSS-SECTION OF HADRON PHOTOPRODUCTION ON Be, C, H2O AND Al NUCLEI IN THE ENERGY RANGE E (gamma) = 200-MeV TO 900-MeV

Arakelian, E.A. ; Bayatian, G.L. ; Grigorian, N.K. ; et al.
EFI-730-45-84-YEREVAN, 1984.
Inspire Record 206946 DOI 10.17182/hepdata.2700

None

2 data tables
Table 1

No description provided.

Table 2

No description provided.


TOTAL CROSS-SECTION OF pi0 MESON PHOTOPRODUCTION ON Be, C, O AND Al NUCLEI IN THE ENERGY RANGE E (gamma) = 180-MeV TO 650-MeV WITHOUT CHARGED PARTICLES IN FINAL STATE

Arakelian, E.A. ; Bayatian, G.L. ; Grigorian, N.K. ; et al.
EFI-729-44-84-YEREVAN, 1984.
Inspire Record 208564 DOI 10.17182/hepdata.2929

None

2 data tables
Table 1

No description provided.

Table 2

No description provided.


MEASUREMENT OF TOTAL pi0 PHOTOPRODUCTION CROSS-SECTION ON THE NUCLEI Be-9, C-12, O-16 IN THE ENERGY RANGE E (gamma) = 0.25-GeV - 1-GeV WITHOUT CHARGED PARTICLES IN FINAL STATE

Arakelian, E.A. ; Bayatian, G.L. ; Grigorian, N.K. ; et al.
Sov.J.Nucl.Phys. 38 (1983) 886, 1983.
Inspire Record 184638 DOI 10.17182/hepdata.17672

None

2 data tables
Table 1

Axis error includes +- 0.0/0.0 contribution (?////NOT GIVEN).

Table 2

Axis error includes +- 0.0/0.0 contribution (?////NOT GIVEN).


Measurement of Total Hadronic Photoproduction Cross-section in $^{9}$Be, $^{12}$C, $^{16}$O, $^{64}$Cu Nuclei in the Photon Energy Range $e \gamma$ = (0.25-{GeV} - 2.7-{GeV})

Arakelian, E.A. ; Bayatian, G.L. ; Grigorian, N.K. ; et al.
Sov.J.Nucl.Phys. 38 (1983) 589, 1983.
Inspire Record 184631 DOI 10.17182/hepdata.17736

None

1 data table
Table 1

No description provided.


MEASUREMENT OF PI- P ---> PI- PI+ N NEAR THRESHOLD AND CHIRAL SYMMETRY BREAKING

Bjork, C.W. ; Jones, S.E. ; King, T.R. ; et al.
Phys.Rev.Lett. 44 (1980) 62-65, 1980.
Inspire Record 157275 DOI 10.17182/hepdata.20699

d2σdΩdT for π+ mesons produced in π−p→π−π+n was measured at seven incident energies between 203 and 357 MeV and the integrated reaction cross section was calculated. The matrix element, when extrapolated to threshold and compared with soft-pion calculations, determined the chiral-symmetry-breaking parameter ξ=0.05±0.26, which is consistent with the Weinberg Lagrangian. The large hard-pion contributions at 203 MeV demonstrated the absolute necessity for comparing at threshold.

1 data table
Table 1

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