Fake Rates for HEEP studies

References

• AN2010_318_v6.pdf, "Search for High-Mass Resonances Decaying to Electron Pairs in the CMS Experiment", p16 onwards.

Mon 21 March 2011

Objective: set up fake rate analysis using the proper CMS PAT environment.

Currently, private code from the MIT group and Drell Yan group, which holds their private variables/cuts etc. Not a CMS wide approach.

From PAT, define our own setup with PATuples. Start from scratch. Standard CMS.

Data

Electron data sets, single photon(electron) trigger, ie EG12?.

Cuts

Reference HEEP document to start.

From the single photon data set:

• Use ECAL and HCAL data only
• Reject any events with 2 or more photons/electrons - gets rid of events with electrons from Zs
• Missing ET cut, Particle Flow MET < 20GeV, - reduces W + jets, to cut out W decays to electrons (need to get W + jets MET dist for check/comparison!)
• H/E cut, H/E < 0.05 at present, ie less than 5% energy in HCAL, to ensure final objects really do look like electrons
• Claim that what remains are "jets" or pi-zeros that "look like" electrons
• If see, for example, 1 event passing all these cuts, for 1000 triggered events, then fake rate is 0.1%

NB

• Tracker data not used at first stage of fake rate analysis
• Preshower yet to make an appearance in the Endcaps!

-- DavidCockerill - 21-Mar-2011