2 Theoretical Background

This chapter discusses theoretical models that describe the physical processes of pion decays. Discussions on the weak force as it relates to the Standard Model (SM) and the conserved vector current hypothesis (CVC) are presented. First order calculations of the [lambda]( p ⁺ -> p ⁰ e⁺ n ) / [lambda]( p ⁺ -> µ⁺ n ) and [lambda]( p ⁺ -> e⁺ n ) / [lambda]( p ⁺ -> µ⁺ n ) branching ratios are presented with discussions on second order corrections.

• 2.1 The weak force
• 2.2 Conserved vector current hypothesis
• 2.3 Calculation of branching ratios