“Comparison of Pair-Production Rate in Vacuum and Plasmas with and without Spin Effects Using Klein-Gordon Equation”

https://pubmed.ncbi.nlm.nih.gov/38115419

This study compares the pair-production rate in vacuum and plasmas, with and without spin effects, using a spinless approximation of the Klein-Gordon equation, finding it to be a good approximation to the Dirac theory under certain conditions.