Comment 2 for bug 1782140

Hi Michael,

In fact, your two command lines use two different formula.

1. For the plot "plot MT(e- met)", we made the vector sum of the 4-momenta and we use the definition:
Mt^2 = E^2 - pz^2 = m^2 + px^2 + py^2 [PDG2018, (47.39)]

2. For the plot "plot MT_MT(e-), we use the formula:
MT^2 = (sum ET^2) - (sum PT^2) [PDG2018, (47.50)]

For system with MET, only the second command line is correct. The first command line gives you a wrong definition of the MT. We will add a warning message for warn people if they use the first command line.

Cheers,
Eric