===== CEPC tracking studies =====

This wiki describe track resolution studies using 2 designs with different outer tracker radius.
The plots are done assuming flat distribution of single muons in |y|<3.

====== Tracker using B=3T and R=1.25m ======
Here is a short description on how to check track resolution using [[http://atlaswww.hep.anl.gov/hepsim/detectorinfo.php?id=sidcc2|CEPC-sidcc2]] detector which has the SiD envelope for tracking (R=1.25 m), 25 um pitch size and 3 Tesla field.
The data are taken from [[http://atlaswww.hep.anl.gov/hepsim/list.php?find=rfull101|rfull101 dataset list]].


Here are the steps to check the resolution using single muons. 
You will need this script {{:fcs:cepc:cepc_track_resolution.py|cepc_track_resolution.py}} and the input dataset
[[http://atlaswww.hep.anl.gov/hepsim/info.php?item=233|pgun_muon_eta3_pt150gev]]

<code bash>
bash   #  set bash if you haven't done this before, and make sure Java is installed. 
wget http://atlaswww.hep.anl.gov/asc/jas4pp/download/current.php -O jas4pp.tgz
tar -zvxf jas4pp.tgz
source jas4pp/setup.sh # takes 5 sec for first-time optimization
hs-get pgun_muon_eta3_pt150gev%rfull101 data 2 500 # get 500 files in 2 threads
# download the python script shown above and run it as
fpad cepc_track_resolution.py
</code>

This script calculates the tracking resolution of this detector as shown below:

{{:fcs:cepc:cepc_resolution_rful101.png?400|}}


Here is the script that does sigma(1/pt). {{ :fcs:cepc:cepc_track_resolution_overpt.py |}}

{{:fcs:cepc:resolution_1overpt.png?400|}}




====== Tracker using B=3T and R=1.8m ======

A new CEPC-Si detector was created using B=3 and R=1.8m tracker, which can fits to the envelope of CEPC-ILD detector,
The new detector, called [[http://atlaswww.hep.anl.gov/hepsim/detectorinfo.php?id=sidcc3|CEPC-sidcc3]],
 with modified tracker was used to create
[[http://atlaswww.hep.anl.gov/hepsim/list.php?find=rfull102|rfull102 dataset list]].


The analysis of this data can be done exactly as before. The only difference is that you will need to download
the different dataset:

<code>
hs-get pgun_muon_eta3_pt150gev%rfull102 data 2 500 # get 500 files in 2 threads
</code>

The track resolutions are shown in 

{{:fcs:cepc:cepc3_res1.png?400|}}


Here is the tracking resolution for 1/pt:


{{:fcs:cepc:cepc_track_resolution_overpt.png?400|}}

The data file is {{ :fcs:cepc:cepc_track_resolution_overpt.jdat |}}.
You can read jdat file in PyROOT using this simple macro {{ :fcs:cepc:make_root.py|script to read jdat files}}


====== Tracking in Barrel and Endcap ======

===== pT resolution =====

As before, this was done using B=3 and R=1.8m tracker and [[http://atlaswww.hep.anl.gov/hepsim/detectorinfo.php?id=sidcc3|CEPC-sidcc3]].

{{:fcs:cepc:cepc_track_resolution_overpt_barrel.png?400|}}

{{:fcs:cepc:cepc_track_resolution_overpt_endcap.png?400|}}

Data files are {{:fcs:cepc:cepc_track_resolution_overpt_barrel.jdat}},  {{:fcs:cepc:cepc_track_resolution_overpt_endcap.jdat}}

The results were created with the scripts {{:fcs:cepc:cepc_track_resolution_overpt_barrel.py}}, {{:fcs:cepc:cepc_track_resolution_overpt_endcap.py}}

===== d0 and z0 resolution =====

{{:fcs:cepc:cepc_track_resolution_d0_barrel.png?400|}}

{{:fcs:cepc:cepc_track_resolution_d0_endcap.png?400|}}

{{:fcs:cepc:cepc_track_resolution_z0_barrel.png?400|}}

{{:fcs:cepc:cepc_track_resolution_z0_endcap.png?400|}}


The files with data are:

  * {{ :fcs:cepc:cepc_track_resolution_z0_barrel.jdat |}}   
  * {{ :fcs:cepc:cepc_track_resolution_z0_endcap.jdat |}}
  * {{ :fcs:cepc:cepc_track_resolution_d0_barrel.jdat |}}
  * {{ :fcs:cepc:cepc_track_resolution_d0_endcap.jdat |}}

===== Some physics plots =====

Here are a few plots illustrating physics performances. The figures have been done using fully identified muons and electrons (PandoraPFO). The following samples (tag rfull102) have been used:

  * [[http://atlaswww.hep.anl.gov/hepsim/info.php?item=148|gev250ee_pythia6_zpole_mumu]] - Z->mu+mu-
  * [[http://atlaswww.hep.anl.gov/hepsim/info.php?item=292|gev250ee_pythia8_higgs_mumu]] - Higgs ->mu+mu+ (all Higgs processes)
  * [[http://atlaswww.hep.anl.gov/hepsim/info.php?item=146|gev250ee_pythia6_zpole_ee]] - Z-> e+e-
  * [[http://atlaswww.hep.anl.gov/hepsim/info.php?item=294|gev250ee_pythia8_zhiggs_nunumumu]] - Z0+Higgs-> nunu+mu+mu-
  * [[http://atlaswww.hep.anl.gov/hepsim/info.php?item=295|gev250ee_pythia8_zhiggs_nunugg]] - Z0+Higgs-> nunu+gg

You can get the data (for Z0+Higgs-> nunu+mu+mu-, for example), as:
<code bash>
bash   #  set bash if you haven't done this before 
wget http://atlaswww.hep.anl.gov/hepsim/soft/hs-toolkit.tgz -O - | tar -xz;
source hs-toolkit/setup.sh
hs-get gev250ee_pythia8_zhiggs_nunumumu          # download ProMC (truth) files
hs-get gev250ee_pythia8_zhiggs_nunumumu%rfull102 # download SLCIO files for rfull102 tag
</code>



See [[http://atlaswww.hep.anl.gov/hepsim/doc/doku.php?id=hepsim:quick|ProMC manual]].


Now you  can convert ProMC data to STDHEP or LCIO (MCParticle) with full simulations using promc2stdhep or promc2lcio converters as discussed in [[hepsim:dev_full|ProMC to LCIO/STDHEP section]].


Here are a few plots that show the performance using [[http://atlaswww.hep.anl.gov/hepsim/info.php?item=148|gev250ee_pythia6_zpole_mumu]]:

{{:fcs:cepc:zpeak_mumu_fit.png?400|}}

Here is the plot for [[http://atlaswww.hep.anl.gov/hepsim/info.php?item=292|gev250ee_pythia8_higgs_mumu]] - Higgs ->mu+mu+ (all Higgs processes)

{{:fcs:cepc:higgs_mumu_fit.png?400|}}

Here is the plot for [[http://atlaswww.hep.anl.gov/hepsim/info.php?item=146|gev250ee_pythia6_zpole_ee]] - Z-> e+e-

{{:fcs:cepc:zpeak_ee_fit.png?400|}}

 --- //[[chekanov@anl.gov|Sergei Chekanov]] 2017/09/07 17:04//