RAPGAP is a Monte Carlo generator which can be used to generate both DIS and Diffractive e+p events.
Currently hosted on GitLab
Contact (for this version)
An installation of RAPGAP can be found in the EIC cmvfs region at
$EICDIRECTORY/PACKAGES/RAPGAP-3.302
When you run RAPGAP, you will create large text files as output. Therefore, you should do so from an appropriate DATA directory. Inside this directory, you should create a soft link to the rapgap executable code:
ln -s $EICDIRECTORY/bin/rapgap33
Now, you need to copy a steer file from the RAPGAP directory to your own directory, so you can edit it and run what you wish. For example:
cp $EICDIRECTORY/PACKAGES/RAPGAP-3.302/data/steer-ep steer
Once this is done, you are ready to run. Once you have edited the file, then you run with the command:
./rapgap33 < steer > rapgap.log
This creates a text file named rapgap.txt with the raw rapgap output. At this point, you are ready to create a ROOT tree and analyze your data.
The ascii output, rapgap.txt, has the following structure:
| I: | 0 (line index) |
|---|---|
| ievent: | eventnumber running from 1 to XXX |
| genevent: | trials to generate this event |
| subprocess: | generated subprocess, for details see page in the rapgap-manual |
| idir: | select type of events to be generated |
| = 1 standard inelastic scattering | |
| = 0 diffractive and pion exchange processes | |
| idisdif: | mixing of standard inelastic scattering, diffractive and pion exchange processes according to cross section |
| 0 generates only the processes selected by IDIR. | |
| 1 mixing of standard inelastic and diffractive processes. | |
| 2 mixing of standard inelastic, diffractive and pion exchange processes | |
| cross section: | integrated cross section |
| error on cross section: | standard deviation of integrated cross section |
| s: | total center of mass energy |
| Q2, y: | in lepto-production: actual Q2 of γ; energy fraction lost by incident electron |
| If radiative corrections are turned on they are different from what is calculated from the scattered lepton. | |
| If radiative corrections are turned off they are the same as what is calculated from the scattered lepton | |
| xgam: | energy fraction of parton on electron side |
| xpr: | energy fraction of parton on proton side |
| pt_hat: | phat_⊥ [GeV/c] of parton in hard subprocess cm system |
| pt2_hat: | phat^2_⊥ [GeV2/c2] of parton in hard subprocess cm system |
| s_hat: | invariant mass ˆs [GeV2] of hard subprocess |
| t_hat: | for diffractive processes T2GKI = t [GeV2] |
| x_pom: | for diffractive processes XFGKI = xIP |
| s_hat: | shat of hard subprocess |
| z: | z = p_i*p_f/p_i*q = ZQGKI |
| x: | xp = Q2/2p_i*q = XPGKI |
| phi: | φ = PHIGKI azimuthal angle |
| nrTracks: | number of tracks in this event, includes also virtual particles |
| I: | line index, runs from 1 to number of particles |
|---|---|
| K(I,1): | status code KS (1: stable particles 11: particles which decay 55; radiative photon) |
| K(I,2): | particle KF code (211: pion, 2112:n, ….) |
| K(I,3): | line number of parent particle |
| K(I,4): | normally the line number of the first daughter; it is 0 for an undecayed particle or unfragmented parton |
| K(I,5): | normally the line number of the last daughter; it is 0 for an undecayed particle or unfragmented parton. |
| P(I,1): | px of particle |
| P(I,2): | py of particle |
| P(I,3): | pz of particle |
| P(I,4): | Energy of particle |
| P(I,5): | mass of particle |
| V(I,1): | x vertex information |
| V(I,2): | y vertex information |
| V(I,3): | z vertex information |
The information from line 7 to X-1 repeats for each event.
Create a ROOT tree using the eic-smear package.
We recommend against using version 3.303. The changes made to support LHAPDF6 seem to make using LHAPDF5 impossible
A number of completed RAPGAP data files for various e+p energies are stored on RCF and can be made available upon request.