Understand low pt photons

See presentation

added to epic &1

assigned to @oeberlin and @mseidel

changed the description

Let me add a little literature overview:

CMS paper EWK-11-016: CADI AN arXiv

• PF photon efficiency wrt to RECO photons for
  E_T
  >10 GeV

CMS EGM papers: EGM-11-001 EGM-17-001

• Tag&probe in Z->ee events,
  E_T
  >20 GeV
• No track and charge requirement on the probe
• Can we extend this to lower energies with J/Psi?

ATLAS EGM paper: PERF-2017-002

1. Radiative Z decays,
   E_T
   range 10-100 GeV, relies on FSR prediction -> not suitable
2. Electron extrapolation,
   E_T
   range 25-150 GeV, T&P with shower shape corrections
3. Inclusive photons,
   E_T
   range 25-1500 GeV, suitable for high/energy photons

added changepatch statusongoing typephysics labels

Regarding J/Psi:

• BParking in 2018
• J/Psi from PU: Presentations of Christian Herwig at EGM meetings in chronological order 1, 2, 3, later on there are presentation/s about displaced electron SFs using Z->ee+gamma 4

Our student Normunds was doing low-pt electron SFs and will help Ojars to run the tools.