N. d'Hose

Total cross section measurement for the three double pion photoproduction channels on the proton

Abstract The total cross sections for the three γp → Nππ reactions have been measured for photon energies from 400 to 800 MeV. The γ p → p π 0 π 0 and γ p → n π + π 0 cross sections have never been measured before while the γ p → p π + π − results are much improved compared to earlier data. These measurements were performed with the large acceptance hadronic detector DAPHNE, at the tagged photon beam facility of the MAMI microtron in Mainz.

First measurement of the Gerasimov-Drell-Hearn integral for Hydrogen from 200 to 800 MeV

A direct measurement of the helicity dependence of the total photoabsorption cross section on the proton was carried out at MAMI (Mainz) in the energy range 200<E_gamma<800 MeV. The experiment used a 4

Measurement of the E2/M1 ratio in the N ---> Delta transition using the reaction p(gamma(pol.),p)pi0

\pi

Helicity amplitudes A1/2 and A3/2 for the D13(1520) resonance obtained from the gamma-->p-->-->ppi(0) Reaction.

detection system, a circularly polarized tagged photon beam and a frozen spin target. The contributions to the Gerasimov-Drell-Hearn sum rule and to the forward spin polarizability

Helicity dependence of the gamma p -> N pi channels and multipole analysis in the Delta region

\gamma_0

Two-body photodisintegration of the deuteron from 100 to 800 MeV

determined from the data are 226 \pm 5 (stat)\pm 12(sys) \mu b and -187 \pm 8 (stat)\pm 10(sys)10^{-6} fm^4, respectively, for 200<E_\gamma<800 MeV.

First determination of generalized polarizabilities of the proton by a virtual compton scattering experiment.

The small electric quadrupole E2 amplitude of the predominantly magnetic dipole M1 p -> Delta(1232) transition has been measured using 270 to 420 MeV tagged linearly polarized photons in the p(gamma,p)pi0 reaction at the Mainz Microtron MAMI. Differential cross sections and photon asymmetries were determined by measuring the recoil proton in the cylindrically symmetric 4pi detector DAPHNE. From the proton angular distributions the ratio E2/M1 = -(2.5+-0.2+-0.2)% at the maximum of the Delta(1232) resonance has been derived.The small electric quadrupole E2 amplitude of the predominantly magnetic dipole M1 p{r_arrow}{Delta}(1232) transition has been measured using 270 to 420MeV tagged linearly polarized photons in the p({gamma}{searrow},p){pi}{sup o} reaction at the Mainz Microtron MAMI. Differential cross sections and photon asymmetries were determined by measuring the recoil proton in the cylindrically symmetric 4{pi} detector DAPHNE. From the proton angular distributions the ratio E2/M1=-(2.5{plus_minus}0.2{plus_minus}0.2){percent} at the maximum of the {Delta}(1232) resonance has been derived. {copyright} {ital 1997} {ital The American Physical Society}

Study of three-nucleon mechanisms in the photodisintegration of 3He

The helicity dependence of the gamma-->p-->-->ppi(0) reaction has been measured for the first time in the photon-energy range from 550 to 790 MeV. The experiment, performed at the Mainz microtron MAMI, used a 4pi-detector system, a circularly polarized, tagged photon beam, and a longitudinally polarized frozen-spin target. These data are predominantly sensitive to the D13(1520) resonance and are used to determine its helicity amplitudes.

Helicity dependence of the reaction in the second resonance region

Abstract.A high-quality double-polarization data set for the helicity dependence of the total and differential cross-sections for both

Two-body photodisintegration of 3He between 200 and 800 MeV

\gamma p\rightarrow N \pi