



@article {2206,
	title = {Observation of bound state self-interaction in a nano-eV atom collider},
	journal = {Nature Communications },
	volume = {9},
	year = {2018},
	month = {2018/11/20},
	abstract = {<p>Quantum mechanical scattering resonances for colliding particles occur when a continuum scattering state couples to a discrete bound state between them. The coupling also causes the bound state to interact with itself via the continuum and leads to a shift in the bound state energy, but, lacking knowledge of the bare bound state energy, measuring this self-energy via the resonance position has remained elusive. Here, we report on the direct observation of self-interaction by using a nano-eV atom collider to track the position of a magnetically-tunable Feshbach resonance through a parameter space spanned by energy and magnetic field. Our system of potassium and rubidium atoms displays a strongly non-monotonic resonance trajectory with an exceptionally large self-interaction energy arising from an interplay between the Feshbach bound state and a different, virtual bound state at a fixed energy near threshold.</p>},
	doi = {https://doi.org/10.1038/s41467-018-07375-8},
	url = {https://arxiv.org/abs/1807.01174},
	author = {Ryan Thomas and Matthew Chilcott and Eite Tiesinga and Amita B. Deb and Niels Kj{\ae}rgaard}
}
