Measurement of the Z boson cross-section in - Harvard University ...

Chapter 4: Data Collection and Event Reconstruction 95
at the luminosity block level. By filtering the luminosity blocks in each run through
a Good Runs List (GRL), we ensure that only those blocks that pass the quality
criteria are used in the analysis. To eliminate events from the beam halo, beam-gas
interactions and cosmic particles, we subsequently select events 6.1 which came from
the crossing of bunches that were known to collide in ATLAS.
The integrated luminosity in the selected luminosity blocks is 331 nb −1 , with an
uncertainty of 11% [94]. Figure 4.1 shows the integrated luminosity delivered and
recorded vs. the day for this run duration. The duration was divided into several
periods, labelled A to D6. Table 4.1 shows the run range and the integrated luminosity
corresponding to each period. Note that ≈ 95% of the data was taken during period
D.
Period Run range Integrated luminosity (nb −1 )
A-C 152844-156682 17.60
D1 158045-158392 28.64
D2 158443-158582 31.76
D3 158632-158975 34.71
D4 158041-159086 87.82
D5 159113 28.38
D6 159179-159224 101.85
Total: 152844-159224 330.8
Table 4.1: Integrated luminosity for the runs in periods A to D corresponding to the
Z Good Runs List. The total integrated luminosity for the dataset is 330.8 nb −1 .
4.2 Event Reconstruction in ATLAS
Event reconstruction starts with raw data from the front-end electronics. The
reconstruction procedures vary between the inner detector (ID), the calorimeters and