Upper limit on the torsion coupling constant

Abstract

Known data are used to place an upper bound on new coupling constants that arise in gravitation with torsion that is derived as the exterior derivative of a potential. The form of the quantum-mechanical interaction is deduced from the classical theory and verified by the nonrelativistic reduction of the Dirac equation. Both minimal and nonminimal coupling is considered. \textcopyright{} 1995 The American Physical Society.