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Measurement of polarization observables $\textbf{T}$, ${\textbf{P}}$, and ${\textbf{H}}$ in $\mathbf {\pi ^0}$ and $\mathbf {\eta }$ photoproduction off quasi-free nucleons

The CBELSA/TAPS collaboration Jermann, N. ; Krusche, B. ; Metag, V. ; et al.
Eur.Phys.J.A 59 (2023) 232, 2023.
Inspire Record 2712592 DOI 10.17182/hepdata.145075

The target asymmetry T, recoil asymmetry P, and beam-target double polarization observable H were determined in exclusive $\pi ^0$ and $\eta $ photoproduction off quasi-free protons and, for the first time, off quasi-free neutrons. The experiment was performed at the electron stretcher accelerator ELSA in Bonn, Germany, with the Crystal Barrel/TAPS detector setup, using a linearly polarized photon beam and a transversely polarized deuterated butanol target. Effects from the Fermi motion of the nucleons within deuterium were removed by a full kinematic reconstruction of the final state invariant mass. A comparison of the data obtained on the proton and on the neutron provides new insight into the isospin structure of the electromagnetic excitation of the nucleon. Earlier measurements of polarization observables in the $\gamma p \rightarrow \pi ^0 p$ and $\gamma p \rightarrow \eta p$ reactions are confirmed. The data obtained on the neutron are of particular relevance for clarifying the origin of the narrow structure in the $\eta n$ system at $W = 1.68\ \textrm{GeV}$. A comparison with recent partial wave analyses favors the interpretation of this structure as arising from interference of the $S_{11}(1535)$ and $S_{11}(1650)$ resonances within the $S_{11}$-partial wave.

4 data tables match query
Figure 4 (a)

Target asymmetry T, recoil asymmetry P, and polarization observable H for $\gamma p \to \pi^0 p$ as a function of the polar center-of-mass angle for bins at the given centroid c.m. energies.

Figure 4 (b)

Target asymmetry T, recoil asymmetry P, and polarization observable H for $\gamma n \to \pi^0 n$ as a function of the polar center-of-mass angle for bins at the given centroid c.m. energies.

Figure 5 (a)

Target asymmetry T, recoil asymmetry P, and polarization observable H for $\gamma p \to \eta p$ as a function of the polar center-of-mass angle for bins at the given centroid c.m. energies.

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Single $\pi^0$ Production Off Neutrons Bound in Deuteron with Linearly Polarized Photons

The A2 at MAMI collaboration Mullen, C. ; Gardner, S. ; Glazier, D.I. ; et al.
Eur.Phys.J.A 57 (2021) 205, 2021.
Inspire Record 1851649 DOI 10.17182/hepdata.127968

The quasifree $\overrightarrow{\gamma} d\to\pi^0n(p)$ photon beam asymmetry, $\Sigma$, has been measured at photon energies, $E_\gamma$, from 390 to 610 MeV, corresponding to center of mass energy from 1.271 to 1.424 GeV, for the first time. The data were collected in the A2 hall of the MAMI electron beam facility with the Crystal Ball and TAPS calorimeters covering pion center-of-mass angles from 49 to 148$^\circ$. In this kinematic region, polarization observables are sensitive to contributions from the $\Delta (1232)$ and $N(1440)$ resonances. The extracted values of $\Sigma$ have been compared to predictions based on partial-wave analyses (PWAs) of the existing pion photoproduction database. Our comparison includes the SAID, MAID, and Bonn-Gatchina analyses; while a revised SAID fit, including the new $\Sigma$ measurements, has also been performed. In addition, isospin symmetry is examined as a way to predict $\pi^0n$ photoproduction observables, based on fits to published data in the channels $\pi^0p$, $\pi^+n$, and $\pi^-p$.

12 data tables match query
Sigma01

Photon beam asymmetry Sigma at W= 1.2711 GeV

Sigma02

Photon beam asymmetry Sigma at W= 1.2858 GeV

Sigma03

Photon beam asymmetry Sigma at W= 1.3003 GeV

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Measurement of the Recoil Proton Polarization in Elastic $\pi^-p$ Scattering at $T_\pi=410$ and 492 MeV

Bareyre, P. ; Bricman, C. ; Longo, M.J. ; et al.
Phys.Rev.Lett. 14 (1965) 878-880, 1965.
Inspire Record 945162 DOI 10.17182/hepdata.21824

None

2 data tables match query
Table 1

No description provided.

Table 2

No description provided.


Investigation of the polarization of Lambda hyperons produced in C-12 C and C-12 Ta interactions at 4.2-GeV/c per nucleon.

Iovchev, K. ; Kladnitskaya, E.N. ; Boldea, V. ; et al.
Sov.J.Nucl.Phys. 47 (1988) 285-286, 1988.
Inspire Record 247551 DOI 10.17182/hepdata.39463

None

2 data tables match query
Table 1

No description provided.

Table 2

No description provided.


$A_y$ in n-d elastic scattering: a test for three-nucleon calculations

Brogli-Gysin, C. ; Campbell, J. ; Haffter, P. ; et al.
Phys.Lett.B 250 (1990) 11-14, 1990.
Inspire Record 1389638 DOI 10.17182/hepdata.29548

We have measured the analyzing power A y in n-d elastic scattering at 67.0 MeV. The experiment was based on the detection of recoil deuterons, allowing for a precise measurement of the backward angular range. The results are in good agreement with recent three-nucleon calculations which are based on the Paris and Bonn NN potentials.

1 data table match query
Table 1

No description provided.


ANGULAR DEPENDENCE OF THE POLARIZATION CORRELATION PARAMETER A(00NN) AND THE ASYMMETRY PARAMETER A(000N) IN ELASTIC PROTON PROTON SCATTERING AT 690-MEV - 950-MEV

Vovchenko, V.G. ; Efimovykh, V.A. ; Zhdanov, A.A. ; et al.
JETP Lett. 44 (1986) 151-154, 1986.
Inspire Record 240718 DOI 10.17182/hepdata.16827

None

2 data tables match query
Table 1

No description provided.

Table 2

No description provided.


CROSS-SECTION ASYMMETRY OF THE gamma n ---> pi- p REACTION BY POLARIZED PHOTONS IN THE THIRD AND FOURTH RESONANCE REGIONS

Adamian, F.V. ; Akopian, G.G. ; Galumian, P.I. ; et al.
EFI-722-37-84-YEREVAN, 1984.
Inspire Record 206944 DOI 10.17182/hepdata.18433

None

5 data tables match query
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Measurements of Cross-section Asymmetry by Polarized Photons and Models of Eta0 Meson Photoproduction in the Energy Range $E_\gamma = 1$-{GeV} to 2-{GeV}

Vartapetian, G.A. ; Piliposian, S.E. ;
Sov.J.Nucl.Phys. 32 (1980) 804, 1980.
Inspire Record 154948 DOI 10.17182/hepdata.18828

None

20 data tables match query
Table 1

No description provided.

Table 2

Axis error includes +- 16/16 contribution.

Table 3

No description provided.

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Investigation of the Energy Dependence of the Spin Spin Correlation in the Diproton Resonance Region

Borisov, N.S. ; Vovchenko, V.G. ; Efimovykh, V.A. ; et al.
Sov.Phys.JETP 54 (1981) 841-847, 1981.
Inspire Record 173719 DOI 10.17182/hepdata.16987

None

2 data tables match query
Table 1

No description provided.

Table 2

No description provided.


Elastic Scattering of 1-GeV Protons by the Nuclei O-16, Ca-40, Ca-42, Ca-44, Ca-48, Ti-48 and Pb-208 in Selfconsistent Theory of Excited Nuclei

Alkhazov, G.D. ; Birbrair, B.L. ; Glezer, S.I. ; et al.
Yad.Fiz. 27 (1978) 333-344, 1978.
Inspire Record 134442 DOI 10.17182/hepdata.70477

Cross sections for elastic scattering of 1 GeV protons from40Ca nuclei have been calculated using the flucton model. The influence of the collective flucton nuclaon correlations on the calculated cross sections is examined. The calculated cross sections are in significant disagreement with the experimental data. This may be considered as an argument against the flucton model.

5 data tables match query
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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