Polarization transfer in the 4^{4}He(e⃗,e′p⃗3(\vec{e},e' \vec{p}^{3}H reaction

Polarization transfer in the 4He(e,e'p)3H reaction at a Q^2 of 0.4 (GeV/c)^2 was measured at the Mainz Microtron MAMI. The ratio of the transverse to the longitudinal polarization components of the ejected protons was compared with the same ratio for elastic ep scattering. The results are consistent with a recent fully relativistic calculation which includes a predicted medium modification of the proton form factor based on a quark-meson coupling model.Comment: 5 pages, Latex, 2 postscript figures, submitted to Physics Letters

Coulomb dissociation reactions on proton-rich Ar isotopes

5 pags., 3 figs., 1 tab. -- 11th Symposium on Nuclei in the Cosmos, 19-23 July 2010, Heidelberg, GermanyA Coulomb dissociation experiment on the proton-rich 32Ar and 34Ar isotopes was performed at the ALADIN-LAND setup at GSI in Darmstadt. Recent RQRPA calculations show a low-lying E1 soft-vibrational mode at an excitation energy Ex ≈ 9 MeV for proton-rich argon isotopes at the dripline. In a macroscopic picture, this can be understood as an out-of-phase oscillation of a thin proton skin against the isospin-saturated core, similar to the neutron pygmy resonance at the neutron dripline. On the other hand, the measured (γ, p) reactions are interesting for the calculation of reaction cross-sections and radiative proton capture rates for the rp-process. In this hydrogen burning process a lot of nuclear structure inputs are still missing. Especially in the argon region a bottleneck for the reaction flow is assumed at 30S and 34Ar. The impact of the predicted proton pygmy resonance on the reaction flow is not yet clear. The experimental motivation and the experiment itself are described. Identification plots for incoming and outgoing particles are shown and a tracking algorithm is applied and shows to work succesfully.This project is supported by the HGF Young Investigators Project VH-NG-327.Peer reviewe

Quasi elastic cross sections for the 209Bi(e,e'p)208Pb reaction: Jefferson Lab experiment E06007

6 pags., 4 figs., 1 tab. -- Rutherford Centennial Conference on Nuclear Physics 8–12 August 2011, Manchester, UKQuasi elastic cross sections were measured for the first time for both negative and positive missing momenta for the 209Bi(e, e′p) 208P b reaction leading to the ground state and hole states of 208P b. Experimental cross sections obtained between -0.3 GeV/c to 0.3 GeV/c agree with theoretical calculations using RDWIA techniques both in shape and magnitude for the ground state. The data for the ground state production of 208P b are consistent with a theoretical model assuming a single proton(1.06 ± 0.10) in the 1h9/2 orbit in 209Bi.Peer reviewe