Gaulard, C.V.
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Measurement of eta photoproduction on the proton from threshold to 1500-MeV

The GRAAL collaboration Bartalini, O. ; Bellini, V. ; Bocquet, J.P. ; et al.
Eur.Phys.J.A 33 (2007) 169-184, 2007.
Inspire Record 755415 DOI 10.17182/hepdata.51526

Beam asymmetry and differential cross section for the reaction gamma+p->eta+p were measured from production threshold to 1500 MeV photon laboratory energy. The two dominant neutral decay modes of the eta meson, eta->2g and eta->3pi0, were analyzed. The full set of measurements is in good agreement with previously published results. Our data were compared with three models. They all fit satisfactorily the results but their respective resonance contributions are quite different. The possible photoexcitation of a narrow state N(1670) was investigated and no evidence was found.

45 data tables
Table 1

Measured beam asymmetry at photon energy 724 MeV as a function of the ETA centre of mass angle.

Table 2

Measured beam asymmetry at photon energy 761 MeV as a function of the ETA centre of mass angle.

Table 3

Measured beam asymmetry at photon energy 810 MeV as a function of the ETA centre of mass angle.

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Measurement of pi0 photoproduction on the proton from 550-MeV to 1500-MeV at GRAAL

The GRAAL collaboration Bartalini, O. ; Bellini, V. ; Bocquet, J.P. ; et al.
Eur.Phys.J.A 26 (2005) 399-419, 2005.
Inspire Record 703671 DOI 10.17182/hepdata.11281

Neutral pion photoproduction has been measured from 550 to 1500 MeV with the GRAAL facility, located at the ESRF in Grenoble. Differential cross-section and beam asymmetry have been measured over a wi

81 data tables
Table 1

Measured differential angular distribution for incident photon energy 555 Mev.

Table 2

Measured differential angular distribution for incident photon energy 578 Mev.

Table 3

Measured differential angular distribution for incident photon energy 597 Mev.

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Analyzing powers for the pi- p(pol.) --> pi0 n reaction across the Delta(1232) resonance.

Gaulard, C.V. ; Riedel, C.M. ; Comfort, Joseph R. ; et al.
Phys.Rev.C 60 (1999) 024604, 1999.
Inspire Record 483795 DOI 10.17182/hepdata.51678

High quality analyzing powers for the π−p→→π0n reaction have been obtained with a polarized proton target over a broad angular range at incident kinetic energies of 98.1, 138.8, 165.9, and 214.4 MeV. This experiment nearly doubled the existing πN single-charge-exchange database for energies ranging from 10 to 230 MeV, with 36 new analyzing powers. The Neutral Meson Spectrometer was used to detect the outgoing neutral pions. The data are well described by recent phase-shift analyses. When combined with high-precision and accurate cross section data at the same energies, the data can provide a good test of the degree of isospin breaking in the region of the Δ(1232) resonance. They will also be helpful for constraining the evaluation of the pion-nucleon σ term from the scattering amplitudes.

4 data tables
Table 1

First error is total uncertainty.

Table 2

First error is total uncertainty.

Table 3

First error is total uncertainty.

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VECTOR MESON PRODUCTION IN HYPERCHARGE EXCHANGE REACTIONS AT 7-GeV/c AND 11.5-GeV/c

Ballam, Joseph ; Brau, J. ; Bouchez, J. ; et al.
Nucl.Phys.B 166 (1980) 189-206, 1980.
Inspire Record 143136 DOI 10.17182/hepdata.34582

Results are presented on vector meson production in the hypercharge exchange reactions: π + p → K ∗+ (890) Y + and K − p→ ρ − Y + where Y + is either Σ + or Y ∗+ (1385). These reactions have been studied at 7 GeV/ c and 11.5 GeV/ c using the SLAC Hybrid Facility. Total and differential cross sections, hyperon polarization, and vector meson decay angular distributions are presented. We find that reactions with Σ + production are dominated by natural parity exchange. The Y ∗ (1385) reactions are consistent with substantial natural parity exchange contributions but also show significant unnatural parity exchange. The differential cross sections and polarization measurements for the vector meson production are compared to the pseudoscalar production reactions.

7 data tables
Table 1

Axis error includes +- 20/20 contribution.

Table 2

Axis error includes +- 20/20 contribution.

Table 3

Axis error includes +- 20/20 contribution.

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Confirmation of Exchange Degeneracy Predictions in the Line Reversed Reactions: $\pi^+ p \to K^+ Y^*(1385)$ and $K^- p \to \pi^- Y^*(1385)$ at 11.6-{GeV}/$c$

Ballam, Joseph ; Bouchez, J. ; Carroll, J.T. ; et al.
Phys.Rev.Lett. 41 (1978) 676, 1978.
Inspire Record 130550 DOI 10.17182/hepdata.20815

We have measured in a single experimental setup the differential cross sections and polarizations of the Y*(1385) produced in the two line-reversed reactions π+p→K+Y*(1385) (260 eV/μb) and K−p→π−Y*(1385) (180 eV/μb) at 11.5 GeV/c. We compare these results to Σ+ production in the same experiment. The data have been derived from a triggered bubble-chamber experiment using the SLAC Hybrid Facility. We find that both helicity-flip-dominated (Y*) and helicity-nonflip-dominated (Σ) processes are consistent with weak-exchange-degeneracy predictions.

5 data tables
Table 1

Axis error includes +- 10/10 contribution.

Table 2

Axis error includes +- 10/10 contribution.

Table 3

Axis error includes +- 10/10 contribution.

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Polarization Measurement of the $\Sigma^+$ Produced in the Line Reversed Reactions $\pi^+ p \to K^+ \Sigma^+$ and $K^- p \to \pi^- \Sigma^+$ at 7-{GeV}/$c$ and 11.6-{GeV}/$c$

Baker, P.A. ; Chima, J.S. ; Dornan, P.J. ; et al.
Phys.Rev.Lett. 40 (1978) 678, 1978.
Inspire Record 129108 DOI 10.17182/hepdata.20914

The polarization of the Σ+ has been measured for the line-reversed reactions π+p→K+Σ+ and K−p→π−Σ+ at 7 and 11.6 GeV/c using the SLAC Hybrid Facility. Since the Σ+ decay is observed in the bubble chamber, the trigger of the flash lamps on a fast K+(π−) did not bias the polarization measurements. We find that the Σ+ polarizations from the two reactions have opposite signs but similar magnitudes and are in much better agreement with the predictions of weak exchange degeneracy than previous lower-energy comparisons.

1 data table
Table 1

No description provided.