Phase Space Cuts

PhaseSpace is base class for all hard-process phase-space generators, either generic 2 -> 1 or 2 -> 2 ones, or specialized ones like for elastic and diffractive scattering.

In it, it is possible to constrain the kinematics of most processes. (Exceptions are "soft physics", i.e. minimum bias, elastic and diffractive processes.) These constraints apply in the rest frame of the hars subprocess, and topologies normally would be changed e.g. by subsequent showering activity.

The more particles in the final state, the more cuts can be applied.

Cuts in all processes

parameter name="PhaseSpace:mHatMin" default="4." min="0."
The minimum invariant mass.

parameter name="PhaseSpace:mHatMax" default="-1."
The maximum invariant mass. A negative value means there is no upper limit.

Cuts in 2 -> 2 processes

parameter name="PhaseSpace:pTHatMin" default="4." min="0."
The minimum invariant pT.

parameter name="PhaseSpace:pTHatMax" default="-1."
The maximum invariant pT. A negative value means there is no upper limit.

parameter name="PhaseSpace:m3Min" default="2." min="0."
The minimum invariant mass of the first product. Only applies in cases where this particle can have a variable mass.

parameter name="PhaseSpace:m3Max" default="-1."
The maximum invariant mass of the first product. Only applies in cases where this particle can have a variable mass. A negative value means there is no upper limit.

parameter name="PhaseSpace:m4Min" default="2." min="0."
The minimum invariant mass of the second product. Only applies in cases where this particle can have a variable mass.

parameter name="PhaseSpace:m4Max" default="-1."
The maximum invariant mass of the second product. Only applies in cases where this particle can have a variable mass. A negative value means there is no upper limit.

Documentation

flag name="PhaseSpace:showSearch" default="off"
Possibility to print information on the search for phase-space coefficients that (in a multichannel approach) provides an analytical upper envelope of the differential cross section, and the corresponding upper estimate of the cross section. Of interest for crosschecks by expert users only.