Black Box Counting Signatures
The following signatures for the Harvard Black Box were generated with the 5 fb-1 data set using our Mathematica event analysis package Chameleon. The following tables also appear in the Chameleon Tutorial file, which is easy to read and modify. In addition to cuts and triggers made by PGS, we have made the following object and event level cuts for these tables:
All kept jets have pT > 50 GeV and |eta| < 3.
We keep a missing energy object if pT > 50 GeV.
There are important physics reasons for making such cuts. PGS (as with any real detector) is unreliable for low pT objects, so we want to remove questionable objects in the event record whenever possible. The cut on jets is particularly conservative, but one can loosen any of these cuts if one wants more information about low pT objects.
In the 47502 events that pass these cuts, the number of particles of a given type are:
(See the Offical Black Box page for a discussion of the meaning of these objects, especially that b-jets are really "heavy-flavor tagged" jets.)
There are 27636 events with missing energy greater than 100 GeV, and 7896 events with missing energy less than 50 GeV. In events with missing energy greater than 100 GeV, the number of photons in each event are:
In events with missing energy less than 50 GeV, the number of photons are:
There are 4593 events with missing energy greater than 100 GeV, at least two jets, and at least two photons. In those events, the jet/lepton breakdown is:
Among all single lepton events, the flavor/charge distribution is:
Among all dilepton events, the flavor/charge distribution is:
Black Box Kinematic Distributions
The following plots have been made using Chameleon. You should make your own plots. Really. It's fun.
First, a histogram of missing energy in each event:
The scalar ET sum of objects in events with zero leptons and four or more jets:
An opposite-sign same-flavor dilepton invariant mass distribution for events with zero jets (electrons/muons only).
An opposite-sign same-flavor dilepton invariant mass distribution for events with 2 or more jets (electrons/muons only).
The same plot with flavor-subtraction. (Flavor subtraction means that we sum the e+e- and mu+mu- distributions and subtract the e+mu- and e-mu+ distributions. This is a way to clean up a distribution if the physics is assumed to be flavor-neutral.)
In events with exactly 2 b-jets, the invariant mass of the two b-jets: