Transverse mass
Encyclopedia
The transverse mass is a useful quantity to define for use in particle physics
as it is invariant under Lorentz boost along the z direction. In natural units
it is:
Hadron collider physicists use another definition of transverse mass, in the case of a decay into two particles:
Particle physics
Particle physics is a branch of physics that studies the existence and interactions of particles that are the constituents of what is usually referred to as matter or radiation. In current understanding, particles are excitations of quantum fields and interact following their dynamics...
as it is invariant under Lorentz boost along the z direction. In natural units
Natural units
In physics, natural units are physical units of measurement based only on universal physical constants. For example the elementary charge e is a natural unit of electric charge, or the speed of light c is a natural unit of speed...
it is:
-
- where the z-direction is along the beam pipe and so
and 
are the momentum perpendicular to the beam pipe and
is the mass.
Hadron collider physicists use another definition of transverse mass, in the case of a decay into two particles:
-
- where
is the transverse energy.
