Bochum 2009 – wissenschaftliches Programm
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HK: Fachverband Hadronen und Kerne
HK 11: Few-body physics
HK 11.5: Vortrag
Montag, 16. März 2009, 15:15–15:30, H-ZO 100
Ab-initio longitudinal response function of 4He — •Sonia Bacca1, Nir Barnea2, Winfried Leidemann3, and Giuseppina Orlandini3 — 1TRIUMF, Vancouver, B.C., Canada — 2Racah Institute of Physics, Hebrew University, Jerusalem, Israel — 3Dipartimento di Fisica, Universita' di Trento and INFN, Italy
We report on our recent ab-initio calculation of the inclusive longitudinal electron scattering off 4He with two- and three-nucleon forces [1]. The full four-body continuum dynamics is considered exactly via the Lorentz integral transform method. We show results for various kinematics up to q=500 MeV/c and compare it with available experimental data. The great importance of the final state interaction is demonstrated. The plane wave impulse approximation particularly fails in the quasi-elastic peak at low energies. The effect of the three-nucleon force results in the reduction of the quasi-elastic peak by 10% for momentum transfers q between 300 and 500 MeV/c. A good agreement with experimental data is found in the peak region. Only at q=500 MeV/c some discrepancies between theory and experiment are present in the low- and high-energy range. Interestingly, the effect of the three-nucleon force increases significantly at lower q, up to about 40% at q=100 MeV/c. Our findings suggest that the longitudinal response function is an electromagnetic observable, where one can learn about the not yet well established three-nucleon force. Unfortunately, at low momentum transfer experimental data are still missing.
[1] S. Bacca, N. Barnea, W. Leidemann, G. Orlandini, arXiv:0811.4624.