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In this paper, a new MC event generator GRAPE-Dilepton
for the dilepton production in collisions is presented.
The FORTRAN code to calculate the Feynman amplitudes
is generated by GRACE [#!GRACE!#]
which is an automatic calculation system.
GRACE has been used mainly for interactions so far.
This is the first time for GRACE to be applied to the case where
there is a composite particle ( i.e. proton) in the initial state.
GRAPE stands for a
GRAce-based generator for
Proton-Electron collisions.
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This generator has the following features.
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- The cross-section calculation is based on the exact matrix elements
in the electroweak theory at tree level.
Not only 2- BH but also the dilepton productions
via Z and ZZ collisions
are taken into account.
CO and Z on/off-shell production
are also included.
Interference effects of the final state
are taken into account in the di- channel.
It is possible to select any sub-set of diagrams in the calculation.
- All fermion masses are kept non-zero
both in the matrix elements and in the kinematics, which makes it
possible to use this program with arbitrary
small scattering angles of and/or
small invariant masses of dilepton
down to the kinematical limits.
- The calculation of the proton vertex covers
the whole kinematical region
by dividing it into 3 categories of
elastic, quasi-elastic and DIS (Deep Inelastic Scattering)
processes,
as described in the next section in detail.
- Both of
Initial State Radiation (ISR) and Final State Radiation (FSR)
can be included.