Hello Mikhail,
Let me just start with your first question.
slic/Geant4 does a very good job of propagating particles through material and
fields and calculating energy depositions along the way.
The readout simulations emulate all of the steps in the detector which occur after
an energy deposition happens in the sensitive detector material. For the silicon
tracker this includes, but is not limited to:
drift and diffusion of charge carriers in the silicon
charge collection on readout strips
electronic readout response modeling
electronic readout noise modeling
overlaying contributions from past and future particles
In order to retain flexibility in any of these processes we do not code that into
slic. Instead, for every G4Step in a sensitive tracking detector we write out the details of
that step in a SimTrackerHit
http://lcio.desy.de/v01-11/doc/doxygen_api/html/classEVENT_1_1SimTrackerHit.html
That information is used during the "digitization" step of the reconstruction.
For the ECal we do not care about the details of all of the secondary particles in
the shower, so we aggragate the contributions of all particle steps in each of the
crystals. That output is written to a SimCalorimeterHit
http://lcio.desy.de/v01-11/doc/doxygen_api/html/classEVENT_1_1SimCalorimeterHit.html
(note that for dedicated studies one can actually save much more detailed information,
but that is not done by default.
Norman
-----Original Message-----
From: [log in to unmask] [mailto:[log in to unmask]] On Behalf Of [log in to unmask]
Sent: Friday, September 19, 2014 9:20 AM
To: hps-software
Subject: MC reconstruction procedure
Dear Colleagues,
I am trying to understand the reconstruction process, but I need some information from the experts.
1) First of all, a naive question: why do we need the "readout simulations"? I guess SLIC is capable to do this job much better than we ever can develop. May I ask what is saved in the SLIC output then?
Energy deposition in various detector pieces only?
2) Do we need a non-zero Run number in MC data, and if so where to set it? Is the following (a small part of) output of recon program acceptable, are all parameters defined for run 0 or even -1 (?):
"No input files in XML file.
Got ConditionsEvent with run: 0
Reading calibrations calibSVT/base for run: 0 Use this calibration from run -1: calibSVT/default.base Reading calibrations calibSVT/tp for run: 0 Use this calibration from run -1: calibSVT/default.tp Loading the SVT bad channels for run 0 File daqmap/svt0.badchannels was not found! Continuing with only QA bad channels Loading fieldmap for run 0"
2) Which is the "officially definitive" detector geometry table for upcoming experiment? "HPS-Proposal2014-v8"?
3) what exactly does pile-up simulation:
org.hps.users.meeg.FilterMCBunches? What do you mean "insert empty bunches"? If they are empty why inserting them? What kind of pile-up is intended here: of particle hits with detector (SVT) noise? of particles from different bunches?
4) if I run reconstruction directly from SLIC output using "/org/hps/steering/readout/HPSTrackingDefaults.lcsim" method, I get something that is missing completely "EcalClusters" (although ECalHits"
are present); there are some "MatchedTracks", but with zero momentum components while D0, phi, omega, TanLambda and Chi2 are not zero.
By the way I still missing the description of D0, phi, omega, TanLambda?
Could you point out where these are described?
5) why the StdHep files linked at confluence page are generated at vertex (0,0,0.1)?
6) How can I change the Track reconstruction parameters: in particular the minimal number of Layers required (are there other parameters)?
Best Regards,
Mikhail.
########################################################################
Use REPLY-ALL to reply to list
To unsubscribe from the HPS-SOFTWARE list, click the following link:
https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=HPS-SOFTWARE&A=1
########################################################################
Use REPLY-ALL to reply to list
To unsubscribe from the HPS-SOFTWARE list, click the following link:
https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=HPS-SOFTWARE&A=1
