Fitting electron tracks in the presence of substantial bremsstrahlung

The problem of reconstructing e+- tracks in bubble chambers in the presence of substantial bremsstrahlung is attacked with a novel approach. The changes in curvature caused by catastrophic bremsstrahlung emission are approximated by piece-wise continuous rates of energy loss, which are determined as parameters in the fit to the measurements. These rates of energy loss are constrained by the a priori expectation in a simple and elegant manner which makes fewer approximations than earlier attempts to introduce constraints. (author)