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Title of program: GRAPE-Dilepton(v1.1)

Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland and from$^{\sim}$abe/grape/.

Operating system under which the program has been tested: UNIX

Programming language used: Fortran77

Memory required to execute with typical data: 7 Mwords for integrations, 9 Mwords for event generations

Keywords: dilepton, lepton-pair, ep collision, Bethe-Heitler, Z boson, dipole form factor, hadron tensor, lepton tensor, structure function, parton density, GRACE

Nature of physical problem: A precise estimation of the cross section of the electroweak dilepton production in $ep$ collisions is required in various physics analyses, where 8$\sim$48 Feynman diagrams can contribute.

Method of solution: The automatic calculation system GRACE is used to obtain all of the relevant helicity amplitudes. The phase space is divided into the 3 regions according to the kinematics at the proton vertex, and the 3 different calculation methods are applied. The radiative corrections are included using the structure function and the parton shower methods.

Restrictions on the complexity of the problem: Higgs, the proton-Z$^0$ coupling and lepton pair production through photon radiation from the proton are not included. The contribution from the resolved photon, i.e. Drell-Yan process in $ep$ collisions is not included.

Typical running time: 1 hour for a cross-section integration and 1 msec per 1 event for an event generation

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Next: Introduction Up: paper Previous: paper
Tetsuo Abe