Cross Section for $\gamma n \to \pi^0 n$ measured at Mainz/A2

The A2 collaboration Briscoe, W.J. ; Hadžimehmedović, M. ; Kudryavtsev, A.E. ; et al.
Phys.Rev.C 100 (2019) 065205, 2019.
Inspire Record 1748263 DOI 10.17182/hepdata.116236

The $\gamma n \to \pi^0 n$ differential cross section evaluated for 27 energy bins span the photon-energy range 290-813 MeV (W = 1.195-1.553 GeV) and the pion c.m. polar production angles, ranging from 18 deg to 162 deg, making use of model-dependent nuclear corrections to extract pi0 production data on the neutron from measurements on the deuteron target. Additionally, the total photoabsorption cross section was measured. The tagged photon beam produced by the 883-MeV electron beam of the Mainz Microtron MAMI was used for the 0-meson production. Our accumulation of 3.6 x 10^6 $\gamma n \to \pi^0 n$ events allowed a detailed study of the reaction dynamics. Our data are in reasonable agreement with previous A2 measurements and extend them to lower energies. The data are compared to predictions of previous SAID, MAID, and BnGa partial-wave analyses and to the latest SAID fit MA19 that included our data. Selected photon decay amplitudes $N^* \to \gamma n$ at the resonance poles are determined for the first time.

21 data tables

Excitation function at pion c.m. angle THETA=18 deg as function of incident photon energy E. The uncertainties are statistical and systematic, combined in quadrature.

Excitation function at pion c.m. angle THETA=32 deg as function of incident photon energy E. The uncertainties are statistical and systematic, combined in quadrature.

Excitation function at pion c.m. angle THETA=41 deg as function of incident photon energy E. The uncertainties are statistical and systematic, combined in quadrature.

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A secondary peak at t = −1 (GeV/c)2 in high energy π-p charge exchange scattering

Sonderegger, P. ; Kirz, J. ; Guisan, O. ; et al.
Phys.Lett. 20 (1966) 75-78, 1966.
Inspire Record 1498686 DOI 10.17182/hepdata.75504

None

23 data tables

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Forward $\pi^-p$ charge exchange scattering between 0.8 and 1.9 GeV

Borgeaud, P. ; Bruneton, C. ; Ducros, Y. ; et al.
Phys.Lett. 10 (1964) 134-137, 1964.
Inspire Record 1400914 DOI 10.17182/hepdata.31224

None

15 data tables

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$\pi^+ p$ interactions at 850 MeV/c

Debaisieux, J. ; Dufour, P. ; Grard, F. ; et al.
Nucl.Phys.B 5 (1968) 147-157, 1968.
Inspire Record 1400916 DOI 10.17182/hepdata.32747

Experimental results are presented on $\pi^+ p$ interactions at 850 MeV/c incident momentum. Cross sections for the various reactions are given. The elastic differential cross section has been fitted to a polynomial in, cos$\theta$ and the resulting coefficients are compared to results at neighbouring incident momenta. For the one-pion-production reactions, the (N$\pi$) effective mass distributions and the ratio of $\pi^0$ to $\pi^+$ production have been compared to the predictions of several theoretical models.

1 data table

No description provided.


High precision measurement of the associated strangeness production in proton proton interactions

The COSY-TOF collaboration Jowzaee, S. ; Borodina, E. ; Clement, H. ; et al.
Eur.Phys.J.A 52 (2016) 7, 2016.
Inspire Record 1393330 DOI 10.17182/hepdata.70735

A new high precision measurement of the reaction pp -> pK+Lambda at a beam momentum of 2.95 GeV/c with more than 200,000 analyzed events allows a detailed analysis of differential observables and their inter-dependencies. Correlations of the angular distributions with momenta are examined. The invariant mass distributions are compared for different regions in the Dalitz plots. The cusp structure at the N Sigma threshold is described with the Flatt\'e formalism and its variation in the Dalitz plot is analyzed.

9 data tables

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Impact parameter dependence of high-energy gamma-ray production in argon induced reaction at 85 MeV/nucleon

Njock, M. Kwato ; Maurel, M. ; Monnand, E. ; et al.
Nucl.Phys.A 489 (1988) 368-380, 1988.
Inspire Record 1389759 DOI 10.17182/hepdata.37000

The double-differential cross sections for high-energy γ-rays were measured for collisions of 36Ar on C, Al, Cu, Ag, Tb, and Au at 85 MeV/nucleon. The system 36Ar+ 27Al has been studied in more detail in an exclusive experiment where the charged-particle multiplicity was measured in coincidence with high-energy γ-rays. A clear correlation between the hardness of the γ-spectra and the overlap distance of the two ions is observed. This correlation is interpreted as due to the spatial dependence of the Fermi momentum of the nucleons.

2 data tables

No description provided.

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Forward scattering of GeV photons from carbon and tungsten

Eisenhandler, E. ; Mistry, N. ; Mostek, P. ; et al.
Phys.Lett.B 24 (1967) 347-348, 1967.
Inspire Record 1389656 DOI 10.17182/hepdata.29584

Small angle (≈3°) scattering of GeV photons from carbon and tungsten has been measured. The results are compared with the predictions of a simple “optical theorem” model, where the total cross-section for photon absorption is taken to be the incoherent sum of absorption on single nucleons.

1 data table

Only stattistical errors are presented.


Phase shift analysis of K+p elastic scattering at 780 MeV/c

Focardi, S. ; Minguzzi-Ranzi, A. ; Monari, L. ; et al.
Phys.Lett.B 24 (1967) 90461 314-317, 1967.
Inspire Record 1389646 DOI 10.17182/hepdata.29618

A phase shift analysis of the K<sup loc="post">+</sup>p elastic scattering at 780 MeV/c has been performed. The experimental differential cross section is best explained by a solution with dominant s wave, negative s wave phase shift (−42.7 ± 1 deg.) and small contributions of p and d waves.

1 data table

Corrected for PI+ P events and scanning efficiency.


Some cross-sections for the photo-production of neutral Pi-mesons from hydrogen at energies from 360 to 938 MeV

Dougan, P. ; Kivikas, T. ; Lugner, K. ; et al.
Z.Phys.A 274 (1975) 73-78, 1975.
Inspire Record 1385254 DOI 10.17182/hepdata.16654

Some cross-sections for the photo-production of ~z~ from hydrogen for pion c.m. angles in the range 60~ ~ are presented. The data have been obtained by measuring proton yields from a hydrogen target, thus permitting separation of single-pion production from the strong background caused by double-pion production. The values, which extend from 360 to 938 MeV, show reasonable agreement with the results of a recent phase-shift analysis

1 data table

No description provided.


Measurement of the g p -> K^0 Sigma^+ reaction with the Crystal Ball/TAPS detectors at the Mainz Microtron

The A2 collaboration Aguar-Bartolome, P. ; Annand, J.R.M. ; Arends, H.J. ; et al.
Phys.Rev.C 88 (2013) 044601, 2013.
Inspire Record 1237227 DOI 10.17182/hepdata.64391

The g p -> K^0 Sigma^+ reaction has been measured from threshold to Eg=1.45 GeV (W_cm=1.9 GeV) using the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. In the present experiment, this reaction was searched for in the 3pi^0 p final state, by assuming K^0_S -> pi^0 pi^0 and Sigma^+ -> pi^0 p. The experimental results include total and differential cross sections as well as the polarization of the recoil hyperon. The new data significantly improve empirical knowledge about the g p -> K^0 Sigma^+ reaction in the measured energy range. The results are compared to previous measurements and model predictions. It is demonstrated that adding the present g p -> K^0 Sigma^+ results to existing data allowed a better description of this reaction with various models.

4 data tables

The differential cross section for photon energies 1125, 1175 and 1225 MeV.

The differential cross section for photon energies 1275, 1325, 1375 and 1425 MeV.

The recoil polarization of the SIGMA+ for photon energy 1125, 1175 and 1225 MeV.

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