Seamus Riordan
[email protected]
March 11, 2016
- Geant4 version 10.1 or later
- cmake >= 3.9
- root 5.34 (root version 6 strongly recommended; ROOT 5 no longer actively supported at JLab)
- python
- git (optional)
See the documentation wiki in the Hall A homepage:
https://hallaweb.jlab.org/wiki/index.php/Documentation_of_g4sbs#Documentation_of_g4sbs:_Overview
Build using the standard cmake facilities. CTEQ tables built in automatically for DIS
If you would like to get on a mail notification list, contact Andrew Puckett ([email protected])
IF YOU ARE DOING DEVELOPMENT, PLEASE DO NOT WORK IN THE master BRANCH
You need the BigBite field map for this as well, which can be found
http://hallaweb.jlab.org/12GeV/SuperBigBite/downloads/map_696A.dat
To build immediately after cloning (not in g4sbs/), create a local "build" directory parallel to the source directory. You can run g4sbs directly in the build folder.
mkdir build
cd build
cmake ../g4sbs
# see below if you get an error about old versions
makeTo run:
./g4sbs run_example.macrun_example.mac demonstrates most of the features by example
NOTE: On the JLab farm, a newer version of cmake is available
So, if it complains about being too old, try:
/apps/cmake/bin/cmake ../g4sbs #########################################################
+z is down the nominal beam axis
+y is "up" (away from gravity)
+x makes a right handed coordinate system
+z is nominally down the "central axis" in the particle direction
+x is "down" (into the floor)
+y makes a right handed coordinate system
#########################################################
Hits in the GEM chambers have tracking performed on them doing straight line fits with resolutions.
At the moment tracking is done in a very dumb way for simplicity!
It will end up averaging all the hits together if there is more
than one track. It would be wise to ensure that tr.nhit <= 4
ev.*
count # Counts given the beam time/luminosity
rate # Counts per second given luminosity
solang # Integrating over this variable will give solid angle
sigma # Cross section [cm^-2]
W2 # Invariant mass squared [GeV^2]
xbj # Bjorken-x
Q2 # Q2 [GeV^2]
th # Polar angle of electron with zaxis [rad]
ph # Azimuthal angle of electron with zaxis [rad]
Aperp # perp component of asymmetry
Apar # parallel component of asymmetry
vx,y,z # Vertex position [cm]
ep # Scattered electron momentum [GeV]
np # Scattered nucleon momentum [GeV]
epx,y,z Lab components of electron momentum [GeV]
npx,y,z Lab components of nucleon momentum [GeV]
nth # Polar angle of nucleon wrt z-axis [rad]
nph Azimuthal angle of nucleon wrt z-axis [rad]
pmperp # Missing momentum perp-component [GeV]
pmpar # Missing momentum par-component [GeV]
nucl # Nucleon when scattering type, 0 for neutron, 1 for proton
fnucl # Final nucleon type (pion prod may change flavor), 0 for neutron, 1 for proton tr.*
x # Track x coordinate intercept with z= 0 plane [m]
y # Track y coordinate intercept with z= 0 plane [m]
xp # Track dx/dz
yp # Track dy/dz
tx,ty,typ,txp
# "True" track variables defined by track projection at first chamber
hcal # 0 if no hit in HCAL, 1 if hit
bb # 0 if no hit in BB cal, 1 if hit
gemtr # 0 if no track found in GEMs, 1 if track found
hcx # HCAL x hit position [cm]
hcy # HCAL y hit position [cm]
bcx # BB cal x hit position [cm]
bcy # BB cal y hit position [cm]
hct # HCAL time-of-flight [ns]
hctex # HCAL expected time-of-flight from momentum-transfer [ns]
hclx,y,z
# HCAL hit position in lab coordinates [cm]
hcdang # HCAL angular difference between q and nucleon p [rad]gen.*
thbb # BigBite angle [rad]
thhcal # HCAL angle [rad]
dbb # BigBite distance from target [m]
dhc # HCAL distance from target [m]
Ebeam # Beam energy [GeV]ht.*
ndata # Number of hits in ht.* array
gid # GEM ID (counting starts at 1)
x,y,z # GEM hit position (incl. resolution effects) [m]
dx,dy # dx/dz and dy/dz of track at hit
tx,ty # "True" GEM hit position (perfect resolution) [m]