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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

Table 1

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.

Table 2

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.

Table 3

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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Reanalysis of Rosenbluth measurements of the proton form factors

Gramolin, A.V. ; Nikolenko, D.M. ;

Phys.Rev.C 93 (2016) 055201, 2016.

Inspire Record 1431987 DOI 10.17182/hepdata.77063

We present a reanalysis of the data from Stanford Linear Accelerator Center (SLAC) experiments E140 [R. C. Walker et al., Phys. Rev. D 49, 5671 (1994)] and NE11 [L. Andivahis et al., Phys. Rev. D 50, 5491 (1994)] on elastic electron-proton scattering. This work is motivated by recent progress in calculating the corresponding radiative corrections and by the apparent discrepancy between the Rosenbluth and polarization transfer measurements of the proton electromagnetic form factors. New, corrected values for the scattering cross sections are presented, as well as a new form factor fit in the $Q^2$ range from 1 to 8.83 $\text{GeV}^2$. We also provide a complete set of revised formulas to account for radiative corrections in single-arm measurements of unpolarized elastic electron-proton scattering.

3 data tables

Table 1

Radiative corrections and differential cross sections obtained by reanalysis of the measurements.

Table 2

Radiative corrections and differential cross sections obtained by reanalysis of the measurements.

Table 3

Radiative corrections and differential cross sections obtained by reanalysis of the measurements.

Elastic scattering of 360 MeV positive $\pi$ mesons by protons

Mitin, N.A. ; Grigor'ev, E.L. ;

Sov.Phys.JETP 5 (1957) 378, 1957.

Inspire Record 1387578 DOI 10.17182/hepdata.39796

Photographic plates were used to study the angular distribotion of 360 plus or minus 10 Mev pi /sup +/ mesons elastically scattered by protons. The differential cross sections derived from 218 scattering events for SP analysis and for SPD analysis are given. The phase shifts which correspond to these distributions are also given.

1 data table

Table 1

No description provided.

Investigation of the Angular Dependence of the Cross Section for Photoproduction of Pions on Nucleons

Adamovich, M.I. ; Larionova, V.G. ; Latypova, R.A. ; et al.

Sov.Phys.JETP 26 344-349, 2015.

Inspire Record 1387574 DOI 10.17182/hepdata.17060

The differential cross sections for they+ p-- n + 7T+ process were measured for y-quantum energies 200, 205 and 210 MeV and meson emission angles 16, 24, 36, 44, 56, 64, 76, 84, 96, 104, 116, 124, 136, 144 and 156° relative to the photon beam in the laboratory system. A phenomenological analysis of the results is carried out and some multipole charged-meson photoproduction amplitudes are determined. The results are compared with the predictions of the dispersion-relation theory.

1 data table

Table 1

Axis error includes +- 4.8/4.8 contribution.

High-precision Measurements of piP Elastic Differential Cross Sections in the Second Resonance Region

The EPECUR collaboration Alekseev, I.G. ; Andreev, V.A. ; Bordyuzhin, I.G. ; et al.

Phys.Rev.C 91 (2015) 025205, 2015.

Inspire Record 1323450 DOI 10.17182/hepdata.67659

Cross sections for pi+-p elastic scattering have been measured to high precision, for beam momenta between 800 and 1240 MeV/c, by the EPECUR Collaboration, using the ITEP proton synchrotron. The data precision allows comparisons of the existing partial-wave analyses (PWA) on a level not possible previously. These comparisons imply that updated PWA are required.

249 data tables

Table 1

Differential cross section of elastic $\pi^+$p-scattering at P= 800.25 MeV/c. Errors shown are statistical only.

Table 2

Differential cross section of elastic $\pi^+$p-scattering at P= 803.75 MeV/c. Errors shown are statistical only.

Table 3

Differential cross section of elastic $\pi^+$p-scattering at P= 807.25 MeV/c. Errors shown are statistical only.

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Photoproduction of Neutral Pions off Protons

The CBELSA/TAPS collaboration Crede, V. ; Sparks, N. ; Wilson, A. ; et al.

Phys.Rev.C 84 (2011) 055203, 2011.

Inspire Record 917921 DOI 10.17182/hepdata.61486

Photoproduction of neutral pions has been studied with the CBELSA/TAPS detector in the reaction $\gamma p\to p\pi^0$ for photon energies between 0.85 and 2.50 GeV. The $\pi^0$ mesons are observed in their dominant neutral decay mode: $\pi^0\to\gamma\gamma$. For the first time, the differential cross sections cover the very forward region, $\theta_{\rm c.m.}<60^\circ$. A partial-wave analysis of these data within the Bonn-Gatchina framework observes the high-mass resonances $G_{17}$(2190), $D_{13}$(2080), and $D_{15}$(2070).

82 data tables

Table 1

Differential cross section for the process GAMMA P --> PI0 P as a function of the cosine of the centre-of-mass scattering angle of the PI0 for photon energies from 0.850 to 0.875 GeV.

Table 2

Differential cross section for the process GAMMA P --> PI0 P as a function of the cosine of the centre-of-mass scattering angle of the PI0 for photon energies from 0.875 to 0.900 GeV.

Table 3

Differential cross section for the process GAMMA P --> PI0 P as a function of the cosine of the centre-of-mass scattering angle of the PI0 for photon energies from 0.900 to 0.925 GeV.

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Study of the gp-->etap reaction with the Crystal Ball detector at the Mainz Microtron(MAMI-C)

The Crystal Ball at MAMI collaboration McNicoll, E.F. ; Prakhov, S. ; Strakovsky, I.I. ; et al.

Phys.Rev.C 82 (2010) 035208, 2010.

Inspire Record 860725 DOI 10.17182/hepdata.56733

The gp-->etap reaction has been measured with the Crystal Ball and TAPS multiphoton spectrometers in the energy range from the production threshold of 707 MeV to 1.4 GeV (1.49 =< W >= 1.87 GeV). Bremsstrahlung photons produced by the 1.5-GeV electron beam of the Mainz Microtron MAMI-C and momentum analyzed by the Glasgow Tagging Spectrometer were used for the eta-meson production. Our accumulation of 3.8 x 10^6 gp-->etap-->3pi0p-->6gp events allows a detailed study of the reaction dynamics. The gp-->etap differential cross sections were determined for 120 energy bins and the full range of the production angles. Our data show a dip near W = 1680 MeV in the total cross section caused by a substantial dip in eta production at forward angles. The data are compared to predictions of previous SAID and MAID partial-wave analyses and to thelatest SAID and MAID fits that have included our data.

121 data tables

Table 1

Total cross section for the reaction GAMMA P --> ETA P.

Table 2

Differential cross section for the reaction GAMMA P --> ETA P at a photon energy of 710.4 MeV. The errors in the table are statistical only and there is an overall systematic uncertainty of 4.3 PCT.

Table 3

Differential cross section for the reaction GAMMA P --> ETA P at a photon energy of 714.5 MeV. The errors in the table are statistical only and there is an overall systematic uncertainty of 4.3 PCT.

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High-energy proton scattering on nuclei

Klovning, A. ; Kofoed-Hansen, O. ; Schluepmann, K. ;

Nucl.Phys.B 54 (1973) 29-41, 1973.

Inspire Record 84178 DOI 10.17182/hepdata.32651

We have studied high-energy proton scattering on Be, C, Cu and Pb targets using a single-arm spectrometer. The projectile momenta were 19 and 24 GeV/ c , the square of the four-momentum transfer varied from t = 0.1 to t = 4.4 GeV 2 . We have recorded momentum distributions of scattered protons in the high-momentum range. An application of multiple-scattering theory yielded agreement of calculation and experimental results to within a ± 30% uncertainty of the former.

3 data tables

Table 1

X ERROR D(OMEGA) = 0.0076 MSR.

Table 2

X ERROR D(OMEGA) = 0.0076 MSR.

Table 3

X ERROR D(OMEGA) = 0.0076 MSR.

Pion-deuteron scattering near the 3-3 resonance

Gabathuler, K. ; Cox, C.R. ; Domingo, J.J. ; et al.

Nucl.Phys.B 55 (1973) 397-407, 1973.

Inspire Record 84138 DOI 10.17182/hepdata.32565

The elastic scattering of positive pions by deuterium has been studied using a scintillating target to detect the recoil deuteron. In addition to the angular distribution measured for 256 MeV incident energy, the energy variation of the fixed angle cross section ( θ lab =160°) has been determined between 141 MeV and 256 MeV. The former is in qualitative agreement with a simple multiple-scattering calculation, but the energy dependence is poorly reproduced.

6 data tables

Table 1

'SMALL-ANGLE TECHNIQUE' - CALIBRATED AT THETA(RF=LAB) OF 30 DEG.

Table 2

'SMALL-ANGLE TECHNIQUE' - CALIBRATED AT THETA(RF=LAB) OF 30 DEG.

Table 3

'LARGE-ANGLE TECHNIQUE' - CALIBRATED AT EACH ANGLE.