Speaker
Leyla Atar
(TU Darmstadt)
Description
According to the Independent Particle Model (IPM) the single particle states are fully occupied with a spectroscopic factor one. However in electron-induced proton knockout reactions a reduction of single-particle strengths has been observed to about 60-70% for stable nuclei in comparison to the IPM. This finding has confirmed by nuclear knockout reactions using stable and exotic beams however with a strong dependency on the proton-neutron asymmetry. To understand this dependency quantitatively a complementary approach, quasi-free reactions, is introduced. Quasi-free knockout reactions in inverse kinematics at relativistic energies allow us to investigate single-particle structure of stable and exotic nuclei in a most direct way.
We have performed a systematic study of spectroscopic strength of Oxygen isotopes using quasi-free (p,2p) and (p,pn) knockout reactions. The Oxygen isotopes offer a large variation of separation energies which allow us to obtain a quantitative understanding of spectroscopic factors in a large variation of isospin asymmetry. For this we performed an experiment at the R3B/LAND setup (at GSI in Darmstadt, Germany) with secondary beams containing 14−24O.
The 16−18O and 21−23O isotopes have been analyzed so far and the preliminary results will be presented. The results include cross sections, momentum distributions and gamma-coincidence measurements. By comparison with the eikonal reaction theory the spectroscopic and reduction factors have been extracted and will be compared to existing data.
The work is supported by HIC for FAIR, GSI-TU Darmstadt cooperation, and BMBF project 05P12RDFN8.
Primary author
Leyla Atar
(TU Darmstadt)
Co-authors
Prof.
Carlos Bertulani
(Texas A&M University-Commerce, USA)
Dr
Stefanos Paschalis
(TU Darmstadt, Germany)
Prof.
Thomas Aumann
(TU Darmstadt)
