Local angular momentum–local impact parameter analysis: A new tool for understanding structure in the angular distributions of chemical reactions

Abstract

A local angular momentum (LAM) and a local impact parameter (LIP) is defined for a state-to-state reaction, whose scattering amplitude can be expanded in a Legendre partial wave series. A nearside–farside decomposition is incorporated into the LAM-LIP theory, which is also extended to resummed partial wave series. The input to a LAM-LIP analysis consists of a set of accurate, or approximate, quantum scattering matrix elements. Application is made to the benchmark F + H₂(v_i = 0, j_i = 0, m_i = 0) → FH(v_f = 3, j_f = 3, m_f = 0) + H reaction, where v_i, j_i, m_i and v_f, j_f, m_f are initial and final vibrational, rotational and helicity quantum numbers respectively. It is demonstrated that a LAM-LIP analysis of structure in the angular scattering provides valuable information on the dynamics of chemical reactions.