FeynCalc manual (development version)

DiracSpinorNormalization

DiracSpinorNormalization is an option for SpinorChainEvaluate, DiracSimplify and other functions. It specifies the normalization of the spinor inner products \bar{u}(p) u(p) and \bar{v}(p) v(p). Following values are supported:

• "Relativistic" - this is the standard value corresponding to \bar{u}(p) u(p) = 2 m, \bar{v}(p) v(p) = - 2 m.

• "Rest" - this sets \bar{u}(p) u(p) = 1, \bar{v}(p) v(p) = - 1.

• "Nonrelativistic" - this sets \bar{u}(p) u(p) = \frac{m}{p^0}, \bar{v}(p) v(p) = - \frac{m}{p^0}.

See also

Overview, DiracSimplify, SpinorChainEvaluate.

Examples

SpinorUBar[p, m] . SpinorU[p, m] 
 
DiracSimplify[%]

\bar{u}(p,m).u(p,m)

2 m

SpinorUBar[p, m] . SpinorU[p, m] 
 
DiracSimplify[%, DiracSpinorNormalization -> "Rest"]

\bar{u}(p,m).u(p,m)

1

SpinorUBar[p, m] . SpinorU[p, m] 
 
DiracSimplify[%, DiracSpinorNormalization -> "Nonrelativistic"]

\bar{u}(p,m).u(p,m)

\frac{m}{p^0}