The t quantity is known as the square of the 4-momentum transfer
[math]t \equiv \left({\mathbf P_1^*}- {\mathbf P_1^{'*}}\right)^2=\left({\mathbf P_2^{*}}- {\mathbf P_2^{'*}}\right)^2[/math]
temp
[math]{\mathbf P_1^{2}}+ {\mathbf P_1^{'2}}[/math]
temp
[math]t \equiv \mathbf {P}_1^2+\mathbf P_1^{'2}-2\mathbf P_1\mathbf P_1^'[/math]
[math]\textbf{\underline{Navigation}}[/math]
[math]\vartriangleleft [/math]
[math]\triangle [/math]
[math]\vartriangleright [/math]