JLCSIM Home Page

This page introduces "JIM" (Full Detector Simulation Program for the JLC physics analysis) and related softwares.

JIM Home Page in Japanese is also prepared (under construction).

[*] What's New?
[*] Getting Started with JIM
[*] Download and Installation
[*] How to Run "JIM"
[*] How to Analize Generated Events

[*] What's New?

Oct. 24, 1999
JLCSIM Version 1.03.00. Sturcture of IT (Intermediate Tracker) is modified according to the scheme poposed by Dr.Hongjoo.
New geometry around the interaction region by Dr.Tauchi is included.
Jul. 22, 1999
JLCSIM Version 1.02.00. Field-map data around the interaction point is included.
Mar. 16, 1999
JLCSIM Version 1.00 is released.
Feb. 23, 1999
JLCSIM Version 0.9 is prepared.
Feb. 19, 1999
English version of JIM home page is now available.

[*] Getting Started

What is "JIM"

"JIM" is "Full Detector Simulation Program for the JLC physics analysis", which is based on the description of the JLC green report. At present, "JIM" can simulate the following detector components.

"JLCSIM" Distribution Package

The "JLCSIM" package distributed on this page includes the following components:

Mailing Lists

There is a mailing list for discussion and announcement about "JIM". In order to subscribe the JIM mailing list, please send an e-mail to "" with

    subscribe jim
in its text field. Address of the list itself is

[*] Download and Installation of the JLCSIM package

Please download jlcsim.tar.gz (700kB) and expand the package as

      zcat jlcsim.tar.gz | tar xvf -
or, in case your tar command supports z option
      tar zxvf jlcsim.tar.gz
Then under the top directory of jlcsim, please execute the imboot command as:
      cd jlcsim
which makes all related libraries, programs and JIM.

This installation procedure is only tested on

Other machines may cause problems in the installation. If you encounter such problems, please report to the administrator of "JLCSIM".

[*] How to run "JIM"

[*] Examples

After above installation procedure, an executable module of JIM should be located under jim/src directory. There is a very simple template script, run_jim, in the same directory. Within this distribution package, there is also an example directory where some sample scripts are prepared. This JIM module can be executed by these commands.

JETSET qq events at ECM=250 GeV
JETSET qq events at ECM=250 GeV in smearing mode.
Pythia HZ events at ECM=250 GeV with mHiggs = 120GeV

[*] Basic input FFREAD cards for JIM

"JIM" requires some input FFREAD cards from standard input.

Total number of events to be processed by "JIM"
Output file name for events generated by "JIM"
Input source for "JIM"
Parameters for the input source given by GEN card.
Input file name in case GEN card specifies file inputs.
Simulation mode for each detectors.

[*] Detailed description of GEN and GENP parameters

JIM can accept various kind of input 4-vectors as its input. User can select input source by the GEN data card as:

        GEN   'source'

Possible input sources are described below:


Generates e+e- -> hadrons with the JETSET74 generator of CERNLIB. CMS energy is given by the first parameter of GENP data card.

        GEN    'LUND'
        GENP   250.
gives hadronic events at ECM=250 GeV.


Generates top quark pair productions with the JETSET74 generator. CMS energy is also given by the first parameter of GENP data card. Default mass of the top quark is set as 174 GeV, which can be changed by the second parameter of GENP CARD.

        GEN    'TOP'
        GENP   500.  175.
gives top quark pair events at ECM=500 GeV with mtop=175 GeV.


Generates Higgs events by PYTHIA (MSEL =16). CMS energy is given by the first parameter of GENP data card. Default mass of the Higgs particle is set to 120 GeV, which can be changed by the second parameter of GENP CARD.

        GEN    'HIGGS'
        GENP   250.  130.
gives top quark pair events at ECM=250 GeV with mHiggs=130 GeV.


Generates a single particle for debugging use. The first parameter of GENP data card gives momentum of generated particles. If it is given in negative value, it gives their transverse momentum. The second parameter gives their JETSET particle code.

If |CODE|<1000, particles are generated to the fixed direction, which is given by the third (theta in degree) and fourth (phi in degree) parameters. If |CODE|>1000, then particles are uniformly generated in the central region which is limited by a veto angle, the third parameter (in degree).

        GEN    'SINGLE'
        GENP   10. 11. 45. 180.
gives electrons with 10 GeV generated into theta=45 degrees and phi=180 degrees.
        GEN    'SINGLE'
        GENP   5. -1013.  60.
gives positive muons with 5 GeV generated uniformly in the central region from 60 to 120 degrees.


Generates multi particles for debugging use. The following list shows the possible GENP parameters:

Momentum of Generated Particles
LUND Particle Code for Generaterd Particle
Number of Generated Particle per event
THETA-min for Generation
THETA-max for Generation
PHI-min for Generation
PHI-max for Generation
X-coordinate for Generation Vertex
Y-coordinate for Generation Vertex
Z-coordinate for Generation Vertex


Read 4-vectors form a file given by VECI data card.

[*] Smearing mode for calorimetric detectors

In order to speed up execution time, some of calorimetric detectors have smearing mode in "JIM". This mode can be given by SIMD data card. If user wants to use smearing mode for a certain detector components, value "1" should be given to the corresponding detector number.

At present the following detectors have smearing mode:

Detector numbers are given in parenthesis. To simulate all these detectors in smearing mode:
      SIMD 3=1 4=1 11=1 12=1

[*] How to Analyize Generated Events

Under util directory, there are some sample programs to analyze events generated by "JIM".

This program converts "JIM" output events into ntuples in "simdst" format. Very simple script, run_ntmake, is prepared as a template.
other programs
Under preparation now. Will appear soon.

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Junichi Kanzaki <>
Last modified: Mon Oct 25 21:44:53 JST 1999