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Three-Body Break-Up Processes at Higher Energies. Hang Liu Charlotte Elster Walter Gl öckle. Supported by: U.S. DOE, NERSC. Full Faddeev. The Solution of Three-Body Amplitude T at Different Orders in Two-Body t -Matrix. 1 st order. 2 nd order. 3 rd order. 4 th order.
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Three-Body Break-Up Processes at Higher Energies Hang Liu Charlotte Elster Walter Glöckle Supported by: U.S. DOE, NERSC
Full Faddeev The Solution of Three-Body Amplitude T at Different Orders in Two-Body t -Matrix 1st order 2nd order 3rd order 4th order Do these expansions at certain orders well approximate the full Faddeev solution ? How do rescattering terms contribute to the total amplitude ?
Break-Up Amplitudes and Cross sections Exclusive Cross Section (two particles measured) Inclusive Cross Section (one particle measured) Total Cross Section
Inclusive Scattering Quasi Free: (QFS) one particle is at rest in lab Maximum amplitude of deuteron state and on-shell t-matrix Final state interaction: (FSI) two particles leave reaction region with zero relative momentum NN scattering length
1st order result accidentally close to the full Faddeev solution at certain energy region
A specific break-up configuration and measurement: the neutron is ejected at extreme backward angles, and the two protons at extreme forward angles, only events with small PP relative energy are measured At 1.0 GeV scale: partial sum up to 3rd order is necessary Convergence improved by going higher orders at backward angle !
Summary • Convergence Properties of Partial Summed Rescattering Contributions at QFS and FSI Region (observed from inclusive process) at higher energies • QFS: • rescattering effects behave regularly, no strong dependence on kinematics, results up to 3rd order is close to that from full Faddeev solution . • FSI: • small emission angle: complicated interference of rescattering effects, strong dependence on the kinematics,full Faddeev solution in general is necessary. • large emission angle: especially the exact backward angle, relatively simple and better convergence properties to validate lower order approximation, however, the 1st order is usually not sufficient.