[QEE] Remove low-mass events from Z->ll lines
Context
There's 'leakage' below 40 GeV making it's way into Hlt2/Sprucing.
This is always cut away anyway offline so we might as well remove it.
We believe it's due to the distinction between `CombinationCut` and `CompositeCut` in the ParticleCombiners. `Combination Cut` = before vertex fit, `CompositeCut` = after vertex fit. So the way the combiners are currently set up, it's possible that there's events that pass the CombinationCut of M>40 GeV, but the events post-vertex-fit have a much lower Mass (as small as 5 GeV).
It's been suggested that these are muons from different PVs (we don't include a vertex requirement).
Effect on Rate/BW
Expected to be small, visually per-cent level of the events being selected by the Zmumu line fit into this category, and it's already relatively low rate
Local test over (the same) 10k events, very minor reduction in Rate, not sensitive enough to extrapolate the reduction with any significance but this is clearly negligible/positive change to my eyes.
# Before
[stack]$ cat qee_hlt2_and_spruce_bandwidth_test__qeeupgrade.log | grep DecisionWithOutput | grep Hlt2QEE | grep ZTo
LAZY_AND: Hlt2QEE_ZToEEFullDecisionWithOutput #=10000 Sum=0 Eff=|( 0.000000 +- 0.00000 )%|
LAZY_AND: Hlt2QEE_ZToMuMuFullDecisionWithOutput #=10000 Sum=0 Eff=|( 0.000000 +- 0.00000 )%|
LAZY_AND: Hlt2QEE_ZToMuMu_DoubleNoMuIDFullDecisionWithOutput #=10000 Sum=1 Eff=|(0.01000000 +- 0.00999950)%|
LAZY_AND: Hlt2QEE_ZToMuMu_SingleNoMuIDFullDecisionWithOutput #=10000 Sum=1 Eff=|(0.01000000 +- 0.00999950)%|
# After
[stack]$ cat qee_hlt2_and_spruce_bandwidth_test__withchanges.log | grep DecisionWithOutput | grep Hlt2QEE | grep ZTo
LAZY_AND: Hlt2QEE_ZToEEFullDecisionWithOutput #=10000 Sum=0 Eff=|( 0.000000 +- 0.00000 )%|
LAZY_AND: Hlt2QEE_ZToMuMuFullDecisionWithOutput #=10000 Sum=0 Eff=|( 0.000000 +- 0.00000 )%|
LAZY_AND: Hlt2QEE_ZToMuMu_DoubleNoMuIDFullDecisionWithOutput #=10000 Sum=0 Eff=|( 0.000000 +- 0.00000 )%|
LAZY_AND: Hlt2QEE_ZToMuMu_SingleNoMuIDFullDecisionWithOutput #=10000 Sum=0 Eff=|( 0.000000 +- 0.00000 )%|
ToDo
-
Local BW Test