Data Set
5.1 Data Set
This analysis uses a Run II dataset collected with the DØ detector from the period April 2002 through February 2006. The data have been processed with the DØ reconstruction software, including the new calorimeter hadronic calibration algorithm. The data were then converted into the DØ Common Analysis Format (CAF) and split into three datasets. Each dataset corresponds to the software version used to reconstruct the data, and the loose selection criteria used to create the dataset. This work uses the single muon loose inclusive datasets which require the presence of at least one muon in the events. Table 5.1 lists the datasets and the number of events in each.
5.1.1 Trigger This analysis uses muon+jets trigger suites which are also used in the top pair production
muon+jets analyses and single top production muon+jets analyses. Since the final state of interest consist of a high p T muon, a hadronic tau which may also be reconstructed as a jet, and two high p T b-jets, the muon+jet trigger suite is a suitable set of triggers for this analysis. Table 5.2 lists the trigger names used in this analysis and their respective luminosity. The total integrated luminosity
− is approximately 994 ± 61 pb 1 . The principal source of uncertainty in the integrated luminosity is the uncertainty in the value of inelastic p¯ p cross-section.
Table 5.1: Names of datasets used in this analysis, and the number of events in each dataset.
Number of events CSG CAF MUinclusive PASS3 p17.09.03
Dataset name
266,513,739 CSG CAF MUinclusive PASS3 p17.09.06
28,198,829 CSG CAF MUinclusive PASS3 p17.09.06b
Table 5.2: Trigger names and their respective luminosities in each trigger version range.
Trigger version range Trigger name Luminosity (pb − 1 ) v8.00-v11.99
125.93 v12.00-v12.99
MU JT20 L2M0
231.14 v13.00-v13.99
MU JT25 L2M0
31.84 v14.00-v14.19
MUJ2 JT25
16.10 v14.00-v14.19
MUJ2 JT25 LM3
255.33 v14.20-v14.29
MUJ2 JT30 LM3
0.01 v14.30-v14.99
MUJ1 JT25 LM3
21.89 v14.20-v14.29
MUJ1 JT25 ILM3
311.92 Total
MUJ1 JT35 LM3
5.1.2 Data quality Events are required to be recorded in data-taking runs that are not considered bad for the following
parts of DØ detector: calorimeter, silicon tracker, fiber tracker, and muon detector [50]. A list of bad luminosity block numbers, specific for the triggers used in the analysis, was generated. Events which are recorded within these bad luminosity blocks are rejected.
Some types of calorimeter noise occur randomly, independent of bad runs list and bad luminosity blocks list discussed before. Events which are flagged bad due to the presence of calorimeter noises are not used in the analysis. This problem needs to be taken into account as an inefficiency. A study with samples of zero-bias events resulted of an efficiency of 97.14% [51]. This is accounted for in the background estimates and signal efficiency.
The size of the single muon inclusive datasets above is large. A working subset of the datasets was made using the following selection criteria:
• Trigger and data quality. • At least one loose isolated muon as defined in Section 3.3 with p T > 15 GeV. • At least one good jet as defined in Section 3.6 with p T > 15 GeV. • Vertex requirement. The event is required to have a primary vertex within the coverage of the
silicon detector, namely the z−position to be less than 60 cm from the center of the detector; and to have at least three tracks attached to the primary vertex.
• The loose muon is required to be coming from the vicinity of the primary vertex, ∆z(µ, vertex) < 1 cm.
There are 237,308 events in the single muon inclusive dataset that pass these cuts. This will be referred as the muon+jets skim.