Variational calculations of low-energy elastic Ps-H scattering

Ps-H scattering is of interest, as it is a fundamental 4-body Coulomb problem, and measurements have been made of Ps scattering with atoms and molecules. We have computed accurate $^{1,3}S$ and $^{1,3}P$ phase shifts for elastic Ps-H scattering using the Kohn, inverse Kohn, generalized Kohn and complex Kohn variational methods [1-3]. We improved upon the numerics of the previous accurate Kohn and inverse Kohn variational calculations [4]. Using the quantum defect theory for the van der Waals interaction [5], we computed the $^1P$ and $^3P$ scattering lengths. We are in the process of computing the $^1D$-wave phase shifts [3].\\[4pt] [1] D. Woods, S. J. Ward and P. Van Reeth, Bull. Am. Phys. Soc. {\bf 56}, no. 5, p. 165 (2011).\\[0pt] [2] Denton Woods, S. J. Ward and P. Van Reeth, Bull. Am. Phys. Soc. {\bf 57}, no. 5, p. 200 (2012); talk at CAARI, Fort Worth, Texas, 2012.\\[0pt] [3] Denton Woods, S. J. Ward and P. Van Reeth, http://meetings.aps.org/Meeting/MAR13/Event/185547.\\[0pt] [4] P. Van Reeth and J. W. Humberston, J. Phys. B {\bf 36}, 1923 (2003); Nucl. Instrum. Methods B {\bf 221} 140 (2004).\\[0pt] [5] Bo Gao, Phys. Rev. A {\bf 58}, 4222 (1998).