时 间: 2011年9月16日（周五）下午3:00

地 点: 清华大学高等研究院 科学馆322报告厅

题 目: Two-body scattering in a unitary gas: anomalous phase shifts and dimers

报 告 人: Junliang Song

Institute of Quantum Optics and Quantum Information of Austrian Academy of Sciences, Innsbruck, Austria

报告摘要: Few-body scattering plays an important role in the low energy properties of quantum gases. In a many-body system, two-body scattering properties can be significantly modified by the medium. We show that in a unitary gas of Fermi-Fermi mixtures, anomalous scattering phase shifts and quasi-dimers with negative masses can appear, as a result of Pauli blocking. We also apply these results to study the lifetime of quasi-particles and dimers at resonances.