Summary of $\pi$--$\pi$ Scattering Experiments

Abstract

Present status of the study of the low energy $\pi \pi$ interaction is reviewed, including the recent results on reactions $\pi N\to \pi \pi N$ near threshold. Current experimental values of s-wave $\pi \pi$ scattering lengths are compared with predictions of various theoretical models. Required experimental and theoretical improvements are discussed, in particular the need for a new $K_{e4}$ decay measurement, and a more reliable theoretical interpretation of the near-threshold $\pi N\to \pi \pi N$ data.

Comments: Talk given at Workshop on Chiral Dynamics, MIT, July 25 - 29 1994. 12 pages, TeX, 3 figs. included in a uuencoded file (psfig.tex required), Springer-Verlag macro "lecproc.cmm", appended at end of TeX file; PostScript file with entire document including figures available at ftp://helena.phys.virginia.edu/pub/preprints/mit_94.ps (467 kB), e-mail: pocanic@virginia.edu