HCAL miscalibration

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Do not try that before CMSSW_1_6_8. Available in CMSSW_1_7_0 and later releases

Enabling the HCAL miscalibration

From CMSSW_1_6_8 onwards, it is possible to run FastSimulation with HCAL miscalibration, using XML files from this release. The default FastSimulation will always run the HCAL miscalibration, though with miscalibration constants all equal to unity. In this sense, there is nothing specific to do to "enable" the HCAL miscalibration for the time being. This documentation will evolve in parallel with the miscalibration tool development, which will most likely tend to use database files instead of local XML files. Stay tuned, then!

Changing the miscalibration scenario

By default, as mentioned above, the HCAL is effectively not miscalibrated although the miscalibration code is run. To apply HCAL miscalibration, it is enough to include the following replace statements (CMSSW < 1_8_0_pre4)

    replace hcalRecHits.Refactor = x.x
    replace hcalRecHits.Refactor_mean = y.y       
in your .cfg file. The first variable (Refactor) is a scaling factor, with respect to a default value of 10%, of the RMS of the miscalibration constants (hence, x.x = 1.0 means 10% RMS miscalibration, 0.5 means 5% RMS miscalibration, 2.0 means 20% RMS miscalibration, etc.) and the second variable (Refactor_mean) is a global miscalibration bias (y.y = 1.0 means no bias, 1.1 means 10% positive bias, etc.). By default, Refactor is set to 0.0 (i.e., no HCAL miscalibration) and Refactor_mean is set to 1.0 (i.e., no global bias)

As of CMSSW_2_1_11, you should instead put (in the python configuration language):

 process.caloRecHits.RecHitsFactory.doMiscalib = True
 process.caloRecHits.RecHitsFactory.HCAL.Refactor = 1.0
 process.caloRecHits.RecHitsFactory.HCAL.Refactor_mean = 1.0
# process.caloRecHits.RecHitsFactory.HCAL.fileNameHcal = "hcalmiscalib_startup.xml"
The last line is commented because it is the default file. Other files are available here. The meaning of Refactor_mean and Refactor is the same as in the previous versions (see the above explanations).

Update CMSSW_2_2_X and 3_X : the HCAL is no-longer mis-calibrated in the startup scenario. Therefore a "dummy" file has been put by default instead. This file doesn't contain anything and as a result as calibration coefficient of 1. is applied. A warning is printed and can be safely ignored.

Note that the above lines will also apply the miscalibration in the ECAL as well. If you want to miscalibrate only the HCAL, you should put in addition

process.caloRecHits.RecHitsFactory.ECALBarrel.Refactor = 0.
process.caloRecHits.RecHitsFactory.ECALEndcap.Refactor = 0.

In the private top group productions, the following parameters have been applied. Some additional information can be found here

Integrated luminosity Gain smearing replace hcalRecHits.Refactor=
0/pb 10% 1.0
10/pb 10% 1.0
100/pb 5% 0.5

Reviewer/Editor and Date (copy from screen) Comments
FlorianBeaudette - 29 Oct 2008 Python config syntax
FlorianBeaudette - 6 December 2007 Updated the documentation for CMSSW > 1_8_0_pre4
PatrickJanot - 16 November 2007 The miscalibration tools are now part of the release
PatrickJanot - 11 September 2007 Update documentation to work with the latest version of the miscalibration tools
PatrickJanot - 29 August 2007 Include documentation with the help of Dimitrios Tsirigkas
PatrickJanot - 29 August 2007 Create template page

Responsible: FlorianBeaudette
Last reviewed by:

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Topic revision: r14 - 2010-03-15 - FlorianBeaudette

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