Difference between revisions of "PID study proposal"

Revision as of 12:11, 28 May 2020

PID Studies

For each final state

• Determine p/theta range of each final state particle
• Compare PID variable distributions between data and MC
  • First stage: 1D distributions integrated over all kinematics
  • Optional: !D distributions from different p/theta bins
  • Do this for each run period under investigation
• Determine selection criteria which are 99% and 95% efficient

Systematic Studies

How to determine systematic uncertainty in efficiency due to PID cuts (assumes you have a final state with some clean peak: rho, phi, pi0, eta, eta'...):

• make tight PID cuts on all particles except the one you are testing the efficiency of - call this particle P
• make two sets of invariant mass distributions for whatever peak you have
  • masses for events in which P satisfies the standard PID requirements
  • masses for events in which P fails the standard PID requirements
• Fit each mass distribution to get the yields: N(pass) and N(fail)
• efficiency of the cut is N(pass) / [N(pass) + N(fail)]
• compare this efficiency between data and MC to determine how well it is modeled
  • Note: need to check for the presence of peaking backgrounds, good to look at bggen MC

Note this probably only works for the timing PID right now. Will need a separate set of files to test CDC dE/dx, but for now just look at the distributions. The biggest contributor here is probably the rate of events without enough hits to properly calculate dE/dx

Apply default cuts with DSelector

In order to apply the default cuts at the DSelector stage, copy the relevant lines into the Init function:

dAnalysisActions.push_back(new DCutAction_PIDDeltaT(dComboWrapper, false, 1.5, Gamma, SYS_BCAL))
dAnalysisActions.push_back(new DCutAction_PIDDeltaT(dComboWrapper, false, 1.5, Gamma, SYS_FCAL))

dAnalysisActions.push_back(new DCutAction_PIDDeltaT(dComboWrapper, false, 1.0, Positron, SYS_BCAL))
dAnalysisActions.push_back(new DCutAction_PIDDeltaT(dComboWrapper, false, 0.5, Positron, SYS_TOF))
dAnalysisActions.push_back(new DCutAction_PIDDeltaT(dComboWrapper, false, 2.0, Positron, SYS_FCAL))
dAnalysisActions.push_back(new DCutAction_PIDDeltaT(dComboWrapper, false, 2.5, Positron, SYS_START))
dAnalysisActions.push_back(new DCutAction_PIDDeltaT(dComboWrapper, false, 1.0, Electron, SYS_BCAL))
dAnalysisActions.push_back(new DCutAction_PIDDeltaT(dComboWrapper, false, 0.5, Electron, SYS_TOF))
dAnalysisActions.push_back(new DCutAction_PIDDeltaT(dComboWrapper, false, 2.0, Electron, SYS_FCAL))
dAnalysisActions.push_back(new DCutAction_PIDDeltaT(dComboWrapper, false, 2.5, Electron, SYS_START))