0000000001299273

AUTHOR

V. Bekrenev

Accurate Test of Chiral Dynamics in the \boldmath$\vec{\gamma} p \rightarrow \pi^0p$ Reaction

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 t…

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Photoproduction of π0-pairs off protons and off neutrons

Total cross sections, angular distributions, and invariant-mass distributions have been measured for the photoproduction of π0π0 pairs off free protons and off nucleons bound in the deuteron. The experiments were performed at the MAMI accelerator facility in Mainz using the Glasgow photon tagging spectrometer and the Crystal Ball/TAPS detector. The accelerator delivered electron beams of 1508 and 1557MeV, which produced bremsstrahlung in thin radiator foils. The tagged photon beam covered energies up to 1400MeV. The data from the free proton target are in good agreement with previous measurements and were only used to test the analysis procedures. The results for differential cross sections…

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Beam-Helicity Asymmetries in Double-Pion Photoproduction off the Proton

Beam-helicity asymmetries have been measured at the MAMI accelerator in Mainz in the three isospin channels $\vec{\gamma}p\to \pi^{+}\pi^0n$, $\vec{\gamma}p\to \pi^{0}\pi^0p$ and $\vec{\gamma}p\to \pi^{+}\pi^{-}p$ . The circularly polarized photons, produced from bremsstrahlung of longitudinally polarized electrons, were tagged with the Glasgow magnetic spectrometer. Charged pions and the decay photons of $\pi^0$ mesons were detected in a $~4\pi$ electromagnetic calorimeter which combined the Crystal Ball detector with the TAPS detector. The precisely measured asymmetries are very sensitive to details of the production processes and are thus key observables in the modeling of the reaction d…

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"dcs09" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.7891 GeV

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"dcs02" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.7319 GeV

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"dcs13" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.8192 GeV

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"dcs04" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.7490 GeV

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"dcs05" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.7568 GeV

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"dcs19" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.8657 GeV

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"dcs06" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.7645 GeV

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"dcs11" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.8045 GeV

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"dcs12" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.8119 GeV

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"tcs" of "Photoproduction of the omega meson off the proton near threshold"

Total cross section as a function of c.m. energy W.

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"dcs17" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.8504 GeV

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"dcs01" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.7245 GeV

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"dcs20" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.8720 GeV

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"dcs18" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.8581 GeV

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"dcs16" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.8424 GeV

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"dcs07" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.7729 GeV

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"dcs03" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.7401 GeV

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"dcs14" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.8269 GeV

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"dcs10" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.7968 GeV

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"dcs08" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.7811 GeV

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"dcs15" of "Photoproduction of the omega meson off the proton near threshold"

Differential cross section at W= 1.8348 GeV

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