Kinematics of an off axis neutrino beam

Abstract

We review the kinematics of a neutrino beam in the idealized case where the parent mesons momenta are parallel, but without other approximation. This reveals several interesting features, in particular in the off-axis case, which are hidden by the approximations made in a previous treatment.

Comments: 14 pages, 4 figures Some typos corrected. Argument in last section streamlined