报告题目: |
Energetics of three particles at a three-body resonance |
报告人: |
Shina Tan |
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Georgia Institute of Technology
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报告时间: |
2015-12-30 16:00 |
报告地点: |
Conference Hall 322, Science Building, Tsinghua University |
主办单位: |
高等研究院 |
简介: |
Ultracold atoms, by definition, have tiny collision energies. It is then natural to develop a systematic perturbation theory in which the collision energy, rather than the interaction potential, is treated as a small parameter. One can expand the N-body wave function in powers of the energy. In this talk I will illustrate this general idea with the three-body system at a three-body resonance, where there is a three-body bound state with zero binding energy. The most important effective three-body parameter at such a resonance is a quantity which we call three-body effective range. If such a system is placed inside a LARGE cubic box with side length L, and the periodic boundary condition is imposed, one would expect a low energy state whose energy goes to zero faster than 1/L^2 at large L. To our surprise, however, there seems to be TWO such low energy states. Their energies both scale like 1/L^3. The theory discussed here is relevant to both ultracold atomic physics and low-energy nuclear physics. |
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