# JetEtmissApproved2013HighMuEtmiss

**Information Common To All Plots**

ρ is calculated using k_{t} R=0.4 jets reconstructed from
locally calibrated (LCW) topoclusters within |η|<2. The density
calculation is with respect to the Voronoi area of the jets as defined
in JHEP 0804 (2008) 005. Topoclusters are an attempt to reconstruct three-dimensional
energy deposits in the calorimeter and are built using a
nearest-neighbor algorithm that clusters calorimeter cells with energy
significance (|E_{cell}|/σ) >4 for the seed, >2 for
neighbors, and >0 at the boundary. E_{cell} is calibrated
using informaton derived from test beam and detailed GEANT4 simulatons
(EM scale) and σ is the sum in quadrature of the electronic and
expected pileup noise, as described in Sec. 10.5.2 of
JINST 3 (2008) S08003. Topoclusters can be further calibrated using local
information (LCW) as described in
Nucl. Instrum. Meth. A 531 (2004) 481. The pileup noise used in
topoclustering is chosen to match the pileup conditons. Pileup is
simulated by overlaying GEANT4 simulated events from PYTHIA (v6.4)
including non-diffractive and diffractive events.

E_{T}^{miss} linearity as a function of the true
E_{T}^{miss} in events with different number of
interactions per bunch crossing (<μ>), in Z'->ttbar
(m_{Z’}=2 TeV) events for 25 ns bunch spacing.
E_{T}^{miss} is calculated taking into account only
the calorimeter deposits. The E_{T}^{miss} linearity
is expected to be zero if the reconstructed
E_{T}^{miss} has the correct scale. The positive bias
at low true E_{T}^{miss} is due to the finite
resolution of the E_{T}^{miss} measurement, and is
highly dependent on the topology of the process studied. For true
E_{T}^{miss} above 150 GeV (250 GeV) and <μ>=40
(<μ>=140), the linearity is within ~1%. The ETmiss value at which
the linearity reaches a constant value increases with <μ>, due to
the poorer resolution in high <μ> events. The evolution of the
resolution as a function of <μ> was also studied and is consistent
with the results shown here.
| [eps] |

Dependence of the pile-up contribution to ∑E_{T} on μ
in Z'->ttbar (m_{Z’}=2 TeV) events with different numbers of
interactions per bunch crossing (<μ>) and 25 ns bunch spacing.
E_{T}^{miss} is calculated taking into account only
the calorimeter deposits. The pileup noise
(σ_{noise}^{pile-up}) used in the topoclustering
is optimized for each value of pileup. The pileup contribution to
∑E_{T} is defined as ∑E_{T}^{PU} =
∑E_{T} – ∑E_{T}^{Truth} where
∑E_{T}^{Truth} is due to all the interacting
particles from the hard scatter, excluding muons. The points are
fitted by ∑E_{T}^{PU}=c√μ. The resolution
worsens as <μ> increases, but the effect is mitigated by use of the
optimized σ_{noise}^{pile-up} value.
| [eps] |

E_{x,y}^{miss} resolution as a function of
∑E_{T} in Z'-> ttbar (m_{Z’}=2 TeV) events and
25 ns bunch spacing, in events with different numbers of interactions
per bunch crossing (<μ>). E_{T}^{miss} is
calculated taking into account only the calorimeter deposits. The
pileup noise (σ_{noise}^{pile-up}) used in the
topoclustering is optimized for each value of <μ>. The resolution
curves are fitted with s+k
√ ∑E_{T}
.
For events with higher levels of pile-up the distribution gets shifted
upwards but does not change its slope as a function of
∑E_{T}. This effectively means that in the resolution
curves the <μ> dependence is absorbed by the s-term, whereas the
k-term remains approximately constant.
| [eps] |

E_{x,y}^{miss} resolution as a function of the number
of truth vertices (N_{vtx}) in Z'-> ttbar (m_{Z’}=2
TeV) events and 25 ns bunch spacing, in events with different numbers
of interactions per bunch crossing (<μ>).
E_{T}^{miss} is calculated taking into account only
the calorimeter deposits. The pileup noise
(σ_{noise}^{pile-up}) used in the topoclustering
is optimized for each value of <μ>. The resolution is fitted with
a straight line to show that the E_{x,y}^{miss}
resolution increases linearly with the number of truth vertices, and
independently of <μ>, when the optimal pileup noise values are used.
| [eps] |

E_{x,y}^{miss} resolution as a function of the number
of truth vertices (N_{vtx}) in events with an average of 40
interactions per bunch crossing (<μ>) for different values of pileup noise (σ_{noise}^{pile-up}) in dijet events at 25 ns bunch spacing. E_{T}^{miss} is calculated taking into account only the calorimeter deposits. In general, tightening σ_{noise}^{pile-up} results in poorer E_{x,y}^{miss} resolution.
| [eps] |

**Major updates**:

-- MichaelBegel - 29-Jul-2013

Responsible: MichaelBegel

Subject: public