ARRA: Universal Quantum Few-Body Codes for Research and Education

We propose to release public software and to develop a graphical-user interface for per- forming accurate quantum mechanical few-body calculations for three-body and four-body systems. This tool will permit general users to perform bound state and low energy scatter- ing calculations for general three-body and four-body systems, given user-specified two-body and three-body potentials. The software will be based on existing effective and reliable codes for solving Faddeev equations in configuration space. The computational procedure has been carefully tested in calculations of extremely sensitive He3 bound states, and of He-He2 scat- tering processes, with outstanding performance. It is fast, straightforward and does not involve manual fine-tuning, as would be needed for other methods. Several emerging areas of physics and astronomy are dependent on reliable and accu- rate theoretical models of few-body interactions. Collective phenomena in dilute, ultra-cold atomic gases, structural properties of van der Waals clusters, and precision measurements of trapped ensembles of atoms or molecules, are examples in which few-body processes dic- tate the behavior or stability of a quantum system. The proposed software will provide a well-tested tool to a broad community of physicists working on problems in nuclear, atomic, molecular and chemical physics, and with applications to myriad areas of physics and as- tronomy It will also provide an ideal learning environment for undergraduate and graduate students studying the impllcations of the rules of quantum mechanics for both real and model systems. Accordingly, it will contribute to the education of both students and researchers in a variety of areas of modern science.