The DTFitter

DTFitter: environment

The same environment provided by the guide is suitable.

DTFitter: downloading and building the code

The source code for the DTFitter is stored in Baltig.

Since the source code of the DTFitter can be downloaded only by the authorized developers, credentials for Baltig are necessary.

The simplest way is using RSA keys, the public key must be uploaded into Baltig and the private key must be saved into ${HOME}/.ssh/id_rsa

Once git client has been correctly configured the commands are:

git clone git@baltig.infn.it:muontomography/DTFitter.git
cd DTFitter

The commands to build the code are:

cmake3 <path-to-source>
make

<path-to-source> is the path to the CMakeLists.txt file in DTFitter directory, e.g.: /home/centos/DTFitter

The executable is found in the directory run/

DTFitter: running the code

The DTFitter application performs the reconstruction of tracks of the Drift Tubes (DT) detectors from:

dataset produced with the castor-simulator software, see The OpenCMT Castor Simulator;
dataset collected with the MUTOMCA apparatus.

Preliminary settings: the configuration file

All the input parameters needed to run the code must be set in a dedicated configuration file config.ini. A template of this file can be found in the utils/ directory and must be copied in the run/ directory. Now you can modify the config.ini file in your run/ directory.

General information

Variable	Type	Description
runNumber	int	number that identifies the dataset to be analyzed
rawDirName	string	path of the input file directory
rawFileName_1	string	name of the input DATA file for DET 0 (file 1_)
rawFileName_2	string	name of the input DATA file for DET 1 (file 2_)
rawFileNameMC	string	name of the input MC file
t0FileName	string	name of the file with the initial t0 (for DATA only)
noiseFileName	string	name of the file with noisy channels (for DATA only)
outputDirName	string	path of the output file directory, e.g. ../output
outputFileName	string	name of the output file
logFileName	string	name of the log file
maxEventNumber	int	maximum number of events to be read

Prototype
Variable Type Description
detector int detector to be analyzed: 1 for DET 0 (file 1_ of DATA), 2 for DET 1 (file 2_ od DATA), or 4 for both

Execution mode

The application can be run in three different modes (please choose only one mode at each execution)

Display mode: show event-per-event display
Histogram mode: fill histograms for track reconstruction analysis, save them in a root output file and eventually display them at the end of execution
TTree mode: fill a root TTree with the reconstructed track parameters and save them in a root output file

Variable	Type	Description
display	bool	set to 1 to run in Display mode, 0 otherwise
start	uint	first event to be visualized with display
histos	bool	set to 1 to run in Histograms mode, 0 otherwise
showHistos	bool	set to 1 to display the histograms at the end of execution
ttree	bool	set to 1 to run in TTree mode, 0 otherwise

Debugging
Variable Type Description
debug bool set to 1 to dump debug messages

Castor MC

Variable	Type	Description
isCastorMC	bool	set to 1 for simulated datasets (0 not implemented for now)
det0Rot	float	DET 0 rotation angle set in the simulation [deg]
det1Rot	float	DET 1 rotation angle set in the simulation [deg]
det0Dist	float	distance of DET 0 center from MC reference frame origin in (x,y) plane [cm]
det1Dist	float	distance of DET 1 center from MC reference frame origin in (x,y) plane [cm]
det0Z	float	z coordinate of DET 0 center in MC reference frame [cm]
det1Z	float	z coordinate of DET 1 center in MC reference frame [cm]
useTrueDriftTimes	bool	use true drift times for the fit (1), or smeared drift times (0)
generateNoise	bool	if true (1), generate randomly distributed noise hits

Fit

Variable	Type	Description
minNHits	int	minimum number of hits accepted in a collection
maxNHits	int	maximum number of hits accepted in a collection
maxPattRecIter	int	maximum number of fit iterations for Pattern Recognition (PR)
sigmaPR	float	3*sigmaPR [mm] set the threshold to reject hits after the PR
maxVertFitIter	int	maximum number of fit iterations for Vertical Fit (VF)
sigmaVF	float	3*sigmaVF [mm] set the threshold to reject hits after the VF
maxDriftTimeFitIter	int	maximum number of fit iterations for the Drift Time Fit (DTF)
sigmaDTF	float	3*sigmaDTF [mm] set the threshold to reject hits after the DTF
maxCHi2MinimizationIter	int	maximum number of iterations for the Chi2 minimization procedure in the DTF
minDeltaChi2	float	minimum value of the Chi2 variation between consecutive iterations needed to stop the Chi2 minimization procedure in the DTF
reducedChi2Limit	float	threshold for Chi2/(n. points - 3): above this value, re-do the DTF with sigmaDTF/2

Preliminary settings: other input files

In order to analyze data, the following .txt files should be added in the /utils/ directory:

in /DTfitter/utils/T0Map/, a file containing the t0, tMin and tMax in ns calculated from the CMS SLs with this format:
```
[event ID] [t0 info] [t0 SL 0] [tMin SL 0]  [tMax SL 0] [t0 SL 1] [tMin SL 1] [tMax SL 1]
```
where [t0 info] is set to MT if a mean timer is present in that event, otherwise to minSL if the minimum of the drift times of that event must be used. Run the Preprocess software with the flag 't0' to obtain a T0Map from un-processed SL data; run the macro utils/readT0FromSL.C to obtain the T0Map from processed SL data.
in /DTfitter/utils/NoiseMap/,a file containing information on eventual noisy channels, with this format:
```
[detector] [board ID] [channel ID] [SW layer ID] [SW tube ID]
```
where [detector] could be either DET0 or DET1.

Other files in the /DTfitter/utils/ directory are:

Space-Time_Parameters.txt: it contains the parameters of the polynomial used to describe the relation between drift distance and the drift time. It should be updated any time a new dataset is analyzed.

ChannelMapTubes.txt: it contains the channel map, that has the following format:

[board ID] [channel ID] [HW layer ID] [HW tube ID] [channel FW] [SW layer ID] [SW tube ID]

DeadChannels.txt: it contains a list with the dead channels, with the same format of the noisy channels file.

Utility

The macro utils/readT0FromSL.C is used to read the output tree files from the PattRec software and get the input t0 for the reconstruction of drift tubes track. How to run (3 possibilities):
```
root 'readT0FromSL.C(runNumber)'
root 'readT0FromSL.C(runNumber, nEvents)'
root 'readT0FromSL.C(runNumber, nEvents, filePath)'
```
In the first case, the number of events to be read from the SL is set to 100M. You can set a different path for the input files. The T0Map file will be saved in the utils/T0Map/ directory.
The macro utils/readDTTree.C can be used as a template to read the output tree files from the DTfitter software itself. How to run:
```
root 'readDTTree.C(filePathAndName)'
```

How to run

cd run
./runDT

Space shortcuts

Page tree