## 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 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 rfull101 dataset list.

Here are the steps to check the resolution using single muons. You will need this script cepc_track_resolution.py and the input dataset pgun_muon_eta3_pt150gev

bash   #  set bash if you haven't done this before, and make sure Java is installed.
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
fpad cepc_track_resolution.py

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

Here is the script that does sigma(1/pt). cepc_track_resolution_overpt.py

# 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 CEPC-sidcc3, with modified tracker was used to create 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:

hs-get pgun_muon_eta3_pt150gev%rfull102 data 2 500 # get 500 files in 2 threads

The track resolutions are shown in

Here is the tracking resolution for 1/pt:

The data file is cepc_track_resolution_overpt.jdat. You can read jdat file in PyROOT using this simple macro 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 CEPC-sidcc3.

The results were created with the scripts cepc_track_resolution_overpt_barrel.py, cepc_track_resolution_overpt_endcap.py

## 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:

You can get the data (for Z0+Higgs→ nunu+mu+mu-, for example), as:

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%rfull102 # download SLCIO files for rfull102 tag

See ProMC manual.

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

Here are a few plots that show the performance using gev250ee_pythia6_zpole_mumu:

Here is the plot for gev250ee_pythia8_higgs_mumu - Higgs →mu+mu+ (all Higgs processes)

Here is the plot for gev250ee_pythia6_zpole_ee - Z→ e+e-

Sergei Chekanov 2017/09/07 17:04