Difference: EventSelection (1 vs. 46)

Revision 46
Changes from r44 to r46
Line: 1 to 1
Changed:
<
<
META TOPICPARENT name="WebHome"
>
>
META TOPICPARENT name="Trash.Trash/Tier3WebHome"
 

Single Top Event Selection

Current Single Top Preselection

Revision 44
Changes from r42 to r44
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Line: 8 to 8
  when selecting for specific channels (s, t or Wt). The second Jet Pt cut is at 25 GeV for low luminosity studies, and at 30 GeV for others (see section on jet pt2 study). Note that for the current sample, there is a selection at the reconstruction level to keep only muons and electrons with Pt > 10 GeV, so the secondary lepton cut effectively removes all secondary leptons.
Changed:
<
<
An isolated muon is defined as having Delta R > 0.4 with respect to all jets in the event.
>
>
A clearer wording of the jet cuts is: at least two jets with Pt > 30 GeV and no more than four jets with Pt > 15 GeV.

An isolated muon or electron is defined as having Etcone20 > 6 with respect to all jets in the event.
 

Lepton Selection

  • At least 1 high-pT lepton (e or isolated μ)
Changed:
<
<
    • Electron pT ≥ 25 GeV
>
>
    • Isolated Electron pT ≥ 25 GeV
 
    • Isolated Muon pT ≥ 20 GeV
Changed:
<
<
    • Lepton (e or isolated μ) |eta| ≤ 2.5
>
>
    • Lepton (isolated e or isolated μ) |eta| ≤ 2.5
 
    • Electron outside of 1.35 < |eta| < 1.65
  • No secondary lepton. A secondary lepton is any e or isolated μ, except the high-pT lepton, with pT ≥ 10 GeV.

Jet Selection

Line: 30 to 32
 
  • ETMiss > 20 GeV

Trigger Selection

  • Electron Triggers
Added:
>
>
    • L1: EM25i OR EM60
    • L2: e25i OR e60
 
    • EF: e25i OR e60
  • Muon Triggers
Added:
>
>
    • L1: MU20i
    • L2: mu20i
 
    • EF: mu20i

Initial Selection Cuts for the Current Analysis

Changed:
<
<
There are four different cut selections, which vary based on the tagged jet number cut and the lepton cuts. This selection contains all events above, but excludes secondary lepton events at this time, as well as events with more than two tagged jets. Since the cuts above eliminate secondary leptons in the current sample, the only implicit cut in this four selection sample is in the b-tagged jet number, since we only look at events with 1 or 2 b-tags.
>
>
There are four different cut selections, which vary based on the tagged jet number cut and the lepton cuts. This selection contains all events above, but excludes secondary lepton events at this time, as well as events with more than two tagged jets. Both leptons are isolated, even if not stated. The important cut in this four selection sample is in the b-tagged jet number, since we only look at events with 1 or 2 b-tags.
 

Cuts for the first sample:

  • Nelectron = 1
  • Nmuon = 0
Line: 142 to 148
 

Changed:
<
<
-- PatRyan - 22 Feb 2007, -- JennyHolzbauer - 10 Sep 2007
>
>
-- PatRyan - 22 Feb 2007, -- JennyHolzbauer - 10 Sep 2007-- JennyHolzbauer - 30 Jan 2008
 

META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863797" name="evt_sel_jet_005501_pt2_one_pt25.png" path="evt_sel_jet_005501_pt2_one_pt25.png" size="22185" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175864017" name="evt_sel_jet_009901_pt2_one_pt30.png" path="evt_sel_jet_009901_pt2_one_pt30.png" size="27083" user="Main.PatRyan" version="1"
Revision 42
Changes from r40 to r42
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Line: 7 to 7
  It is the most general event selection applied to single top samples and is refined further when selecting for specific channels (s, t or Wt). The second Jet Pt cut is at 25 GeV for low luminosity studies, and at 30 GeV for others (see section on jet pt2 study). Note that for the current sample, there is a selection at the reconstruction level to keep only muons and electrons with Pt > 10 GeV, so the secondary lepton cut effectively removes all secondary leptons.
Changed:
<
<
An isolated muon is defined as having Delta R > 0.4 with respect to the jets in the event.
>
>

An isolated muon is defined as having Delta R > 0.4 with respect to all jets in the event.
 

Lepton Selection

  • At least 1 high-pT lepton (e or isolated μ)
Line: 15 to 16
 
    • Isolated Muon pT ≥ 20 GeV
    • Lepton (e or isolated μ) |eta| ≤ 2.5
    • Electron outside of 1.35 < |eta| < 1.65
Changed:
<
<
  • No secondary lepton (e or isolated μ) of a different sign than the primary lepton, with both
    • pT ≥ 10 GeV
>
>
  • No secondary lepton. A secondary lepton is any e or isolated μ, except the high-pT lepton, with pT ≥ 10 GeV.
 

Jet Selection

Changed:
<
<
  • 2 ≤ NJet ≤ 4, where the Jet 1 has pT ≥ 30 GeV, Jet 2 has pT ≥ 25 GeV, Jets 3 and 4 have pT ≥ 15 GeV
  • Jet |eta| ≤ 5.0
  • NB-Jet ≥ 1; where the 1 B-jet has pT ≥ 30 GeV
>
>
  • 2 ≤ NJet ≤ 4
  • Jet pT
    • Jet 1 pT ≥ 30 GeV
    • Jet 2 pT ≥ 25 GeV
    • Jet 3 pT ≥ 15 GeV
    • Jet 4 pT ≥ 15 GeV
  • Jet |eta| ≤ 5.0 for Jets 1, 2, 3, and 4
  • NB-Jet ≥ 1; where the 1 B-jet has pT ≥ 30 GeV and |eta| ≤ 2.5
 

Other Selection Criteria

  • ETMiss > 20 GeV

Trigger Selection

Revision 40
Changes from r38 to r40
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Current Single Top Preselection

The followin event selection is based upon that proposed by Arnaut Lucotte and recently discussed by the Single-Top group. It is the most general event selection applied to single top samples and is refined further
Changed:
<
<
when selecting for specific channels (s, t or Wt). The second Jet Pt cut is at 25 GeV for low luminosity studies, and at 30 GeV for others (see section on jet pt2 study). Note that for the current sample, there is a selection at the reconstruction level to keep only muons and electrons with Pt > 10 GeV, so the secondary lepton cut effectively removes all secondary leptons. An isolated muon is defined as having Delta R > 0.4 with respect to the jets in the event.
>
>
when selecting for specific channels (s, t or Wt). The second Jet Pt cut is at 25 GeV for low luminosity studies, and at 30 GeV for others (see section on jet pt2 study). Note that for the current sample, there is a selection at the reconstruction level to keep only muons and electrons with Pt > 10 GeV, so the secondary lepton cut effectively removes all secondary leptons. An isolated muon is defined as having Delta R > 0.4 with respect to the jets in the event.
 

Lepton Selection

  • At least 1 high-pT lepton (e or isolated μ)
Line: 124 to 126
  also causing about a 20% increase in Wbb background. For early data studies it is important to include as many signal events as possible and therefore the increase in signal events outweights the subsequent increase in the background.
Changed:
<
<
However, the Wbb sample is very sensitive in the region of the cut (29% for 5 GeV change) and it may not be safe
>
>
However, the Wbb sample is very sensitive in the region of the cut (29% for 5 GeV change) and it may not be safe
  to lower the value, especially since the normalization of the Wbb background is not known apriori (20% errors taken apriori). Also, the jet re-calibration for low-pt jets may introduce uncertainties in the JES, (corrections are very important for lower pT jets) which will reflect in the systematics.
Revision 38
Changes from r36 to r38
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Current Single Top Preselection

The followin event selection is based upon that proposed by Arnaut Lucotte and recently discussed by the Single-Top group. It is the most general event selection applied to single top samples and is refined further
Changed:
<
<
when selecting for specific channels (s, t or Wt). The second Jet Pt cut is at 25 GeV for low luminosity studies, and at 30 GeV for others (see section on jet pt2 study). Note that for the current sample, there is a selection at the reconstruction level to keep only muons and electrons with Pt > 10 GeV, so the secondary lepton cut effectively removes all secondary leptons
>
>
when selecting for specific channels (s, t or Wt). The second Jet Pt cut is at 25 GeV for low luminosity studies, and at 30 GeV for others (see section on jet pt2 study). Note that for the current sample, there is a selection at the reconstruction level to keep only muons and electrons with Pt > 10 GeV, so the secondary lepton cut effectively removes all secondary leptons. An isolated muon is defined as having Delta R > 0.4 with respect to the jets in the event.
 

Lepton Selection

Changed:
<
<
  • At least 1 high-pT lepton (e or μ)
>
>
  • At least 1 high-pT lepton (e or isolated μ)
 
    • Electron pT ≥ 25 GeV
    • Isolated Muon pT ≥ 20 GeV
    • Lepton (e or isolated μ) |eta| ≤ 2.5
    • Electron outside of 1.35 < |eta| < 1.65
Changed:
<
<
  • No secondary lepton (e or μ) of a different sign than the primary lepton, with both
>
>
  • No secondary lepton (e or isolated μ) of a different sign than the primary lepton, with both
 
    • pT ≥ 10 GeV

Jet Selection

  • 2 ≤ NJet ≤ 4, where the Jet 1 has pT ≥ 30 GeV, Jet 2 has pT ≥ 25 GeV, Jets 3 and 4 have pT ≥ 15 GeV
Revision 36
Changes from r34 to r36
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Current Single Top Preselection

The followin event selection is based upon that proposed by Arnaut Lucotte and recently discussed by the Single-Top group. It is the most general event selection applied to single top samples and is refined further
Changed:
<
<
when selecting for specific channels (s, t or Wt). The second Jet Pt cut is at 25 GeV for low luminosity studies, and at 30 GeV for others (see section on jet pt2 study).
>
>
when selecting for specific channels (s, t or Wt). The second Jet Pt cut is at 25 GeV for low luminosity studies, and at 30 GeV for others (see section on jet pt2 study). Note that for the current sample, there is a selection at the reconstruction level to keep only muons and electrons with Pt > 10 GeV, so the secondary lepton cut effectively removes all secondary leptons
 

Lepton Selection

  • At least 1 high-pT lepton (e or μ)
    • Electron pT ≥ 25 GeV
Changed:
<
<
    • Muon pT ≥ 20 GeV
    • Lepton (e or μ) |eta| ≤ 2.5
>
>
    • Isolated Muon pT ≥ 20 GeV
    • Lepton (e or isolated μ) |eta| ≤ 2.5
 
    • Electron outside of 1.35 < |eta| < 1.65
  • No secondary lepton (e or μ) of a different sign than the primary lepton, with both
    • pT ≥ 10 GeV
Deleted:
<
<
    • |eta| ≤ 2.5
 

Jet Selection

Changed:
<
<
  • 2 ≤ NJet ≤ 4, where the Jet 1 has pT ≥ 30 GeV and Jet 2 has pT ≥ 25 GeV
  • NB-Jet ≥ 1; where the 1 B-jet has pT ≥ 35 GeV
>
>
  • 2 ≤ NJet ≤ 4, where the Jet 1 has pT ≥ 30 GeV, Jet 2 has pT ≥ 25 GeV, Jets 3 and 4 have pT ≥ 15 GeV * Jet |eta| ≤ 5.0
  • NB-Jet ≥ 1; where the 1 B-jet has pT ≥ 30 GeV
 

Other Selection Criteria

Changed:
<
<
  • ETMiss > 25 GeV
>
>
  • ETMiss > 20 GeV
 

Trigger Selection

  • Electron Triggers
Changed:
<
<
    • L1: 2EM15I
    • L2: e15iL2_e15i
    • EF: e15iEF_e15i
>
>
    • EF: e25i OR e60
 
  • Muon Triggers
Changed:
<
<
    • L1: MU06
    • L2: mu06
    • EF: mu06
>
>
    • EF: mu20i
 

Initial Selection Cuts for the Current Analysis

Changed:
<
<
There are four different cut selections, which vary based on the tagged jet number cut and the lepton cuts. This selection contains all events above, but excludes secondary lepton events at this time, as well as events with more than two tagged jets.
>
>
There are four different cut selections, which vary based on the tagged jet number cut and the lepton cuts. This selection contains all events above, but excludes secondary lepton events at this time, as well as events with more than two tagged jets. Since the cuts above eliminate secondary leptons in the current sample, the only implicit cut in this four selection sample is in the b-tagged jet number, since we only look at events with 1 or 2 b-tags.
 

Cuts for the first sample:

  • Nelectron = 1
  • Nmuon = 0
Line: 139 to 135
 

Changed:
<
<
-- PatRyan - 22 Feb 2007, -- JennyHolzbauer - 23 Aug 2007
>
>
-- PatRyan - 22 Feb 2007, -- JennyHolzbauer - 10 Sep 2007
 

META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863797" name="evt_sel_jet_005501_pt2_one_pt25.png" path="evt_sel_jet_005501_pt2_one_pt25.png" size="22185" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175864017" name="evt_sel_jet_009901_pt2_one_pt30.png" path="evt_sel_jet_009901_pt2_one_pt30.png" size="27083" user="Main.PatRyan" version="1"
Revision 34
Changes from r32 to r34
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Line: 13 to 13
 
    • Muon pT ≥ 20 GeV
    • Lepton (e or μ) |eta| ≤ 2.5
    • Electron outside of 1.35 < |eta| < 1.65
Changed:
<
<
  • No secondary lepton (e or μ) with both
>
>
  • No secondary lepton (e or μ) of a different sign than the primary lepton, with both
 
    • pT ≥ 10 GeV
    • |eta| ≤ 2.5

Jet Selection

Revision 32
Changes from r30 to r32
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Line: 17 to 17
 
    • pT ≥ 10 GeV
    • |eta| ≤ 2.5

Jet Selection

Changed:
<
<
  • NJet ≥ 2, where the Jet 1 has pT ≥ 30 GeV and Jet 2 has pT ≥ 25 GeV
>
>
  • 2≤ NJet ≤ 4, where the Jet 1 has pT ≥ 30 GeV and Jet 2 has pT ≥ 25 GeV
 
  • NB-Jet ≥ 1; where the 1 B-jet has pT ≥ 35 GeV

Other Selection Criteria

  • ETMiss > 25 GeV
Revision 30
Changes from r28 to r30
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Line: 9 to 9
 

Lepton Selection

  • At least 1 high-pT lepton (e or μ)
Changed:
<
<
    • Electron pT >= 25 GeV
    • Muon pT >= 20 GeV
    • Lepton (e or μ) |eta| <= 2.5
    • Electron outside of 1.35 < |eta| < 1.65
>
>
    • Electron pT ≥ 25 GeV
    • Muon pT ≥ 20 GeV
    • Lepton (e or μ) |eta| ≤ 2.5
    • Electron outside of 1.35 < |eta| < 1.65
 
  • No secondary lepton (e or μ) with both
Changed:
<
<
    • pT > 10 GeV
    • |eta| <= 2.5
>
>
    • pT ≥ 10 GeV
    • |eta| ≤ 2.5
 

Jet Selection

Changed:
<
<
  • NJet ≥ 2, where the Jet 1 has pT > 30 GeV and Jet 2 has pT > 25 GeV
  • NB-Jet ≥ 1; where the 1 B-jet has pT > 35 GeV
>
>
  • NJet ≥ 2, where the Jet 1 has pT ≥ 30 GeV and Jet 2 has pT ≥ 25 GeV
  • NB-Jet ≥ 1; where the 1 B-jet has pT ≥ 35 GeV
 

Other Selection Criteria

  • ETMiss > 25 GeV

Trigger Selection

Line: 139 to 139
 

Changed:
<
<
-- PatRyan - 22 Feb 2007, -- JennyHolzbauer - 01 Aug 2007
>
>
-- PatRyan - 22 Feb 2007, -- JennyHolzbauer - 23 Aug 2007
 

META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863797" name="evt_sel_jet_005501_pt2_one_pt25.png" path="evt_sel_jet_005501_pt2_one_pt25.png" size="22185" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175864017" name="evt_sel_jet_009901_pt2_one_pt30.png" path="evt_sel_jet_009901_pt2_one_pt30.png" size="27083" user="Main.PatRyan" version="1"
Revision 28
Changes from r26 to r28
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Current Single Top Preselection

The followin event selection is based upon that proposed by Arnaut Lucotte and recently discussed by the Single-Top group. It is the most general event selection applied to single top samples and is refined further
Changed:
<
<
when selecting for specific channels (s, t or Wt). The second Jet Pt cut is at 25 GeV for low luminosity studies, and at 30 GeV for others.
>
>
when selecting for specific channels (s, t or Wt). The second Jet Pt cut is at 25 GeV for low luminosity studies, and at 30 GeV for others (see section on jet pt2 study).
 

Lepton Selection

  • At least 1 high-pT lepton (e or μ)
Changed:
<
<
    • Electron pT >eq; 25 GeV
    • Muon pT >eq; 20 GeV
>
>
    • Electron pT >= 25 GeV
    • Muon pT >= 20 GeV
 
    • Lepton (e or μ) |eta| <= 2.5
    • Electron outside of 1.35 < |eta| < 1.65
  • No secondary lepton (e or μ) with both
Revision 26
Changes from r24 to r26
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Current Single Top Preselection

Changed:
<
<
The followin event selection is based upon that proposed by Arnaut Lucotte.
>
>
The followin event selection is based upon that proposed by Arnaut Lucotte and recently discussed by the Single-Top group.
  It is the most general event selection applied to single top samples and is refined further
Changed:
<
<
when selecting for specific channels (s, t or Wt).
>
>
when selecting for specific channels (s, t or Wt). The second Jet Pt cut is at 25 GeV for low luminosity studies, and at 30 GeV for others.
 

Lepton Selection

  • At least 1 high-pT lepton (e or μ)
Changed:
<
<
    • Electron pT > 25 GeV
    • Muon pT > 20 GeV
>
>
    • Electron pT >eq; 25 GeV
    • Muon pT >eq; 20 GeV
    • Lepton (e or μ) |eta| <= 2.5
    • Electron outside of 1.35 < |eta| < 1.65
 
  • No secondary lepton (e or μ) with both
    • pT > 10 GeV
Changed:
<
<
    • -1.475 < η < 1.475
>
>
    • |eta| <= 2.5
 

Jet Selection

  • NJet ≥ 2, where the Jet 1 has pT > 30 GeV and Jet 2 has pT > 25 GeV
  • NB-Jet ≥ 1; where the 1 B-jet has pT > 35 GeV

Other Selection Criteria

  • ETMiss > 25 GeV
Added:
>
>

Trigger Selection

  • Electron Triggers
    *L1
    2EM15I
    *L2
    e15iL2_e15i
    *EF
    e15iEF_e15i
  • Muon Triggers
    *L1
    MU06
    *L2
    mu06
    *EF
    mu06
 

Initial Selection Cuts for the Current Analysis

Changed:
<
<
There are four different cut selections, which vary based on the tagged jet number cut and the lepton cuts. The secondary lepton cut is not applied here, because the samples will contain only one lepton (electron or isolated muon). However, the rest of the preselection cuts have already been applied. Isolated muon is currently defined as a muon with no jet within 0.4 DeltaR of it.

Cuts for all selections:

  • NJet ≤ 4, where the Jet 3 has pT > 15 GeV and Jet 4 has pT > 15 GeV
>
>
There are four different cut selections, which vary based on the tagged jet number cut and the lepton cuts. This selection contains all events above, but excludes secondary lepton events at this time, as well as events with more than two tagged jets.
 

Cuts for the first sample:

  • Nelectron = 1
Changed:
<
<
  • Nisolated muon = 0
>
>
  • Nmuon = 0
 
  • NB-Jet = 1

Cuts for the second sample:

  • Nelectron = 1
Changed:
<
<
  • Nisolated muon = 0
>
>
  • Nmuon = 0
 
  • NB-Jet = 2
Deleted:
<
<
  • 2 B-Jet has pT > 15 GeV
 

Cuts for the third sample:

Added:
>
>
  • Nmuon = 1
 
  • Nelectron = 0
Deleted:
<
<
  • Nisolated muon = 1
 
  • NB-Jet = 1

Cuts for the fourth sample:

Added:
>
>
  • Nmuon = 1
 
  • Nelectron = 0
Deleted:
<
<
  • Nisolated muon = 1
 
  • NB-Jet = 2
Deleted:
<
<
  • 2 B-Jet has pT > 15 GeV
 

Investigation of the Jet 2 pT cut

Signal Samples

Line: 132 to 139
 

Changed:
<
<
-- PatRyan - 22 Feb 2007
>
>
-- PatRyan - 22 Feb 2007, -- JennyHolzbauer - 01 Aug 2007
 

META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863797" name="evt_sel_jet_005501_pt2_one_pt25.png" path="evt_sel_jet_005501_pt2_one_pt25.png" size="22185" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175864017" name="evt_sel_jet_009901_pt2_one_pt30.png" path="evt_sel_jet_009901_pt2_one_pt30.png" size="27083" user="Main.PatRyan" version="1"
Revision 24
Changes from r22 to r24
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Line: 21 to 21
 
  • ETMiss > 25 GeV

Initial Selection Cuts for the Current Analysis

Changed:
<
<
There are four different cut selections, which vary based on the tagged jet number cut and the lepton cuts. The secondary lepton cut is not applied here, because the samples will contain only one lepton (electron or isolated muon). Isolated muon is currently defined as a muon with no jet within 0.4 DeltaR of it.

Cuts for all selections, after the preselection cuts (except for the secondary lepton cut):

>
>
There are four different cut selections, which vary based on the tagged jet number cut and the lepton cuts. The secondary lepton cut is not applied here, because the samples will contain only one lepton (electron or isolated muon). However, the rest of the preselection cuts have already been applied. Isolated muon is currently defined as a muon with no jet within 0.4 DeltaR of it.

Cuts for all selections:

 
  • NJet ≤ 4, where the Jet 3 has pT > 15 GeV and Jet 4 has pT > 15 GeV
Changed:
<
<

Cuts for the first sample, 1 electron and 1 b-tagged jet:

>
>

Cuts for the first sample:

 
  • Nelectron = 1
  • Nisolated muon = 0
  • NB-Jet = 1
Changed:
<
<

Cuts for the second sample, 1 electron and 2 b-tagged jets:

>
>

Cuts for the second sample:

 
  • Nelectron = 1
  • Nisolated muon = 0
  • NB-Jet = 2
  • 2 B-Jet has pT > 15 GeV
Changed:
<
<

Cuts for the third sample, 1 isolated muon and 1 b-tagged jet:

>
>

Cuts for the third sample:

 
  • Nelectron = 0
  • Nisolated muon = 1
  • NB-Jet = 1
Changed:
<
<

Cuts for the fourth sample, 1 isolated muon and 2 b-tagged jets:

>
>

Cuts for the fourth sample:

 
  • Nelectron = 0
  • Nisolated muon = 1
  • NB-Jet = 2
Revision 22
Changes from r20 to r22
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Line: 20 to 20
 

Other Selection Criteria

  • ETMiss > 25 GeV
Added:
>
>

Initial Selection Cuts for the Current Analysis

There are four different cut selections, which vary based on the tagged jet number cut and the lepton cuts. The secondary lepton cut is not applied here, because the samples will contain only one lepton (electron or isolated muon). Isolated muon is currently defined as a muon with no jet within 0.4 DeltaR of it.

Cuts for all selections, after the preselection cuts (except for the secondary lepton cut):

  • NJet ≤ 4, where the Jet 3 has pT > 15 GeV and Jet 4 has pT > 15 GeV

Cuts for the first sample, 1 electron and 1 b-tagged jet:

  • Nelectron = 1
  • Nisolated muon = 0
  • NB-Jet = 1

Cuts for the second sample, 1 electron and 2 b-tagged jets:

  • Nelectron = 1
  • Nisolated muon = 0
  • NB-Jet = 2
  • 2 B-Jet has pT > 15 GeV

Cuts for the third sample, 1 isolated muon and 1 b-tagged jet:

  • Nelectron = 0
  • Nisolated muon = 1
  • NB-Jet = 1

Cuts for the fourth sample, 1 isolated muon and 2 b-tagged jets:

  • Nelectron = 0
  • Nisolated muon = 1
  • NB-Jet = 2
  • 2 B-Jet has pT > 15 GeV
 

Investigation of the Jet 2 pT cut

Signal Samples

In the original event preselection, the pT cut on both jets was 30 GeV. However, requiring that the Jet 2 pT was greater than 30 GeV
Revision 20
Changes from r18 to r20
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Line: 32 to 32
  For pTJet 2 > 25 GeV, a moderate number of events are removed, and for pTJet 2 > 20 GeV, amost no events are removed.
Changed:
<
<
evt_sel_jet_005501_pt2_one_pt30.png" evt_sel_jet_005501_pt2_one_pt25.png" evt_sel_jet_005501_pt2_one_pt20.png"
>
>
evt_sel_jet_005501_pt2_one_pt30.png" evt_sel_jet_005501_pt2_one_pt25.png" evt_sel_jet_005501_pt2_one_pt20.png"

evt_sel_jet_005502_pt2_one_pt30.png" evt_sel_jet_005502_pt2_one_pt25.png" evt_sel_jet_005502_pt2_one_pt20.png"

evt_sel_jet_005500_pt2_one_pt30.png" evt_sel_jet_005500_pt2_one_pt25.png" evt_sel_jet_005500_pt2_one_pt20.png"
 

Background Samples

The effects of different Jet 2 pT cuts on a Wbb background sample was also studied since a major role of this cut is to limit
Line: 44 to 48
  and pTJet 2 > 20 GeV. It can been seen that as the cut is lowered, more events remain in the sample.
Added:
>
>
evt_sel_jet_009901_pt2_one_pt30.png" evt_sel_jet_009901_pt2_one_pt25.png" evt_sel_jet_009901_pt2_one_pt20.png"

Table Sumarizing Results

Effect of Jet 2 pT Cut

The table belows the immediate effect of the Jet 2 pT cut. It shows the number of events before the cut, the number of events after the cut, and the percentage decrease in the number of events as a result of the cut.
Channel Jet 2 pT Cut (GeV) Events Before Cut Events After Cut % Decrease
s 20 20602 20570 0.2
s 25 20602 18860 9.2
s 30 20602 16806 22.6
         
t 20 2627 2626 0.04
t 25 2627 2513 4.5
t 30 2627 2361 11.3
         
Wt 20 26139 26121 0.07
Wt 25 26139 25105 4.1
Wt 30 26139 23593 10.8
         
Wbb 20 158474 158461 0.01
Wbb 25 158474 132094 20.0
Wbb 30 158474 106307 49.1

Effect of Jet 2 pT Cut on Final Sample

The table belows the effect of the Jet 2 pT cut on the final sample. It shows the number of events in the final sample for different Jet 2 pT cut in addition to the number of events in the final sample for a Jet 2 pT cut of 30 GeV. The percent increase in the number of events in the final sample for a certain Jet 2 pT cut over the number of events in the sample with a Jet 2 pT cut of 30 GeV is also shown.
Channel Jet 2 pT Cut (GeV) Final Events Final (30 GeV) % Increase
s 20 16177 13604 18.9
s 25 15038 13604 10.5
s 30 13604 13604 0.0
         
t 20 1845 1708 8.0
t 25 1792 1708 4.9
t 30 1708 1708 0.0
         
Wt 20 16858 15709 7.3
Wt 25 16430 15709 4.6
Wt 30 15709 15709 0.0
         
Wbb 20 132829 93821 41.6
Wbb 25 113996 93821 21.5
Wbb 30 93821 93821 0.0

Summary of Jet 2 pT Study

Moving the Jet 2 pT cut causes a 5-10% increase of signal events depending on the channel while also causing about a 20% increase in Wbb background. For early data studies it is important to include as many signal events as possible and therefore the increase in signal events outweights the subsequent increase in the background.

However, the Wbb sample is very sensitive in the region of the cut (29% for 5 GeV change) and it may not be safe to lower the value, especially since the normalization of the Wbb background is not known apriori (20% errors taken apriori). Also, the jet re-calibration for low-pt jets may introduce uncertainties in the JES, (corrections are very important for lower pT jets) which will reflect in the systematics.

The single top group has decided that the cut of 25 GeV will be used for early data studies while the cut of 30 GeV will be used for high luminosity studies.

 

-- PatRyan - 22 Feb 2007
Revision 18
Changes from r16 to r18
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Line: 32 to 32
  For pTJet 2 > 25 GeV, a moderate number of events are removed, and for pTJet 2 > 20 GeV, amost no events are removed.
Changed:
<
<
| evt_sel_jet_005501_pt2_one_pt30.png" | evt_sel_jet_005501_pt2_one_pt25.png" | evt_sel_jet_005501_pt2_one_pt20.png" |
>
>
evt_sel_jet_005501_pt2_one_pt30.png" evt_sel_jet_005501_pt2_one_pt25.png" evt_sel_jet_005501_pt2_one_pt20.png"
 

Background Samples

The effects of different Jet 2 pT cuts on a Wbb background sample was also studied since a major role of this cut is to limit contamination from soft jets in the background. However, in the t-channel, the Wbb is probably not a significant background, and in the s-channel,
Line: 47 to 46
 

-- PatRyan - 22 Feb 2007
Added:
>
>
 
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863797" name="evt_sel_jet_005501_pt2_one_pt25.png" path="evt_sel_jet_005501_pt2_one_pt25.png" size="22185" user="Main.PatRyan" version="1"
Added:
>
>
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175864017" name="evt_sel_jet_009901_pt2_one_pt30.png" path="evt_sel_jet_009901_pt2_one_pt30.png" size="27083" user="Main.PatRyan" version="1"
 
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863869" name="evt_sel_jet_005502_pt2_one_pt25.png" path="evt_sel_jet_005502_pt2_one_pt25.png" size="22369" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863741" name="evt_sel_jet_005500_pt2_one_pt25.png" path="evt_sel_jet_005500_pt2_one_pt25.png" size="23791" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863904" name="evt_sel_jet_005502_pt2_one_pt30.png" path="evt_sel_jet_005502_pt2_one_pt30.png" size="22382" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863819" name="evt_sel_jet_005501_pt2_one_pt30.png" path="evt_sel_jet_005501_pt2_one_pt30.png" size="22195" user="Main.PatRyan" version="1"
Added:
>
>
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863951" name="evt_sel_jet_009901_pt2_one_pt25.png" path="evt_sel_jet_009901_pt2_one_pt25.png" size="27104" user="Main.PatRyan" version="1"
 
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863849" name="evt_sel_jet_005502_pt2_one_pt20.png" path="evt_sel_jet_005502_pt2_one_pt20.png" size="22363" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863760" name="evt_sel_jet_005500_pt2_one_pt30.png" path="evt_sel_jet_005500_pt2_one_pt30.png" size="23780" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863714" name="evt_sel_jet_005500_pt2_one_pt20.png" path="evt_sel_jet_005500_pt2_one_pt20.png" size="23789" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863929" name="evt_sel_jet_009901_pt2_one_pt20.png" path="evt_sel_jet_009901_pt2_one_pt20.png" size="27113" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863777" name="evt_sel_jet_005501_pt2_one_pt20.png" path="evt_sel_jet_005501_pt2_one_pt20.png" size="22199" user="Main.PatRyan" version="1"
Deleted:
<
<
META FILEATTACHMENT attachment="evt_sel_jet_009901_pt2_one_pt25.png" attr="" comment="" date="1175863951" name="evt_sel_jet_009901_pt2_one_pt25.png" path="evt_sel_jet_009901_pt2_one_pt25.png" size="27104" stream="evt_sel_jet_009901_pt2_one_pt25.png" user="Main.PatRyan" version="1"
Revision 16
Changes from r14 to r16
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Line: 50 to 50
 
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863797" name="evt_sel_jet_005501_pt2_one_pt25.png" path="evt_sel_jet_005501_pt2_one_pt25.png" size="22185" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863869" name="evt_sel_jet_005502_pt2_one_pt25.png" path="evt_sel_jet_005502_pt2_one_pt25.png" size="22369" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863741" name="evt_sel_jet_005500_pt2_one_pt25.png" path="evt_sel_jet_005500_pt2_one_pt25.png" size="23791" user="Main.PatRyan" version="1"
Added:
>
>
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863904" name="evt_sel_jet_005502_pt2_one_pt30.png" path="evt_sel_jet_005502_pt2_one_pt30.png" size="22382" user="Main.PatRyan" version="1"
 
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863819" name="evt_sel_jet_005501_pt2_one_pt30.png" path="evt_sel_jet_005501_pt2_one_pt30.png" size="22195" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863849" name="evt_sel_jet_005502_pt2_one_pt20.png" path="evt_sel_jet_005502_pt2_one_pt20.png" size="22363" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863760" name="evt_sel_jet_005500_pt2_one_pt30.png" path="evt_sel_jet_005500_pt2_one_pt30.png" size="23780" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863714" name="evt_sel_jet_005500_pt2_one_pt20.png" path="evt_sel_jet_005500_pt2_one_pt20.png" size="23789" user="Main.PatRyan" version="1"
Added:
>
>
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863929" name="evt_sel_jet_009901_pt2_one_pt20.png" path="evt_sel_jet_009901_pt2_one_pt20.png" size="27113" user="Main.PatRyan" version="1"
 
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863777" name="evt_sel_jet_005501_pt2_one_pt20.png" path="evt_sel_jet_005501_pt2_one_pt20.png" size="22199" user="Main.PatRyan" version="1"
Changed:
<
<
META FILEATTACHMENT attachment="evt_sel_jet_005502_pt2_one_pt30.png" attr="" comment="" date="1175863903" name="evt_sel_jet_005502_pt2_one_pt30.png" path="evt_sel_jet_005502_pt2_one_pt30.png" size="22382" stream="evt_sel_jet_005502_pt2_one_pt30.png" user="Main.PatRyan" version="1"
>
>
META FILEATTACHMENT attachment="evt_sel_jet_009901_pt2_one_pt25.png" attr="" comment="" date="1175863951" name="evt_sel_jet_009901_pt2_one_pt25.png" path="evt_sel_jet_009901_pt2_one_pt25.png" size="27104" stream="evt_sel_jet_009901_pt2_one_pt25.png" user="Main.PatRyan" version="1"
Revision 14
Changes from r12 to r14
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Line: 48 to 48
 

-- PatRyan - 22 Feb 2007
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863797" name="evt_sel_jet_005501_pt2_one_pt25.png" path="evt_sel_jet_005501_pt2_one_pt25.png" size="22185" user="Main.PatRyan" version="1"
Added:
>
>
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863869" name="evt_sel_jet_005502_pt2_one_pt25.png" path="evt_sel_jet_005502_pt2_one_pt25.png" size="22369" user="Main.PatRyan" version="1"
 
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863741" name="evt_sel_jet_005500_pt2_one_pt25.png" path="evt_sel_jet_005500_pt2_one_pt25.png" size="23791" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863819" name="evt_sel_jet_005501_pt2_one_pt30.png" path="evt_sel_jet_005501_pt2_one_pt30.png" size="22195" user="Main.PatRyan" version="1"
Added:
>
>
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863849" name="evt_sel_jet_005502_pt2_one_pt20.png" path="evt_sel_jet_005502_pt2_one_pt20.png" size="22363" user="Main.PatRyan" version="1"
 
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863760" name="evt_sel_jet_005500_pt2_one_pt30.png" path="evt_sel_jet_005500_pt2_one_pt30.png" size="23780" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863714" name="evt_sel_jet_005500_pt2_one_pt20.png" path="evt_sel_jet_005500_pt2_one_pt20.png" size="23789" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863777" name="evt_sel_jet_005501_pt2_one_pt20.png" path="evt_sel_jet_005501_pt2_one_pt20.png" size="22199" user="Main.PatRyan" version="1"
Changed:
<
<
META FILEATTACHMENT attachment="evt_sel_jet_005502_pt2_one_pt20.png" attr="" comment="" date="1175863848" name="evt_sel_jet_005502_pt2_one_pt20.png" path="evt_sel_jet_005502_pt2_one_pt20.png" size="22363" stream="evt_sel_jet_005502_pt2_one_pt20.png" user="Main.PatRyan" version="1"
>
>
META FILEATTACHMENT attachment="evt_sel_jet_005502_pt2_one_pt30.png" attr="" comment="" date="1175863903" name="evt_sel_jet_005502_pt2_one_pt30.png" path="evt_sel_jet_005502_pt2_one_pt30.png" size="22382" stream="evt_sel_jet_005502_pt2_one_pt30.png" user="Main.PatRyan" version="1"
Revision 12
Changes from r10 to r12
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Line: 47 to 47
 

-- PatRyan - 22 Feb 2007
Added:
>
>
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863797" name="evt_sel_jet_005501_pt2_one_pt25.png" path="evt_sel_jet_005501_pt2_one_pt25.png" size="22185" user="Main.PatRyan" version="1"
 
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863741" name="evt_sel_jet_005500_pt2_one_pt25.png" path="evt_sel_jet_005500_pt2_one_pt25.png" size="23791" user="Main.PatRyan" version="1"
Added:
>
>
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863819" name="evt_sel_jet_005501_pt2_one_pt30.png" path="evt_sel_jet_005501_pt2_one_pt30.png" size="22195" user="Main.PatRyan" version="1"
 
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863760" name="evt_sel_jet_005500_pt2_one_pt30.png" path="evt_sel_jet_005500_pt2_one_pt30.png" size="23780" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863714" name="evt_sel_jet_005500_pt2_one_pt20.png" path="evt_sel_jet_005500_pt2_one_pt20.png" size="23789" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863777" name="evt_sel_jet_005501_pt2_one_pt20.png" path="evt_sel_jet_005501_pt2_one_pt20.png" size="22199" user="Main.PatRyan" version="1"
Changed:
<
<
META FILEATTACHMENT attachment="evt_sel_jet_005501_pt2_one_pt25.png" attr="" comment="" date="1175863796" name="evt_sel_jet_005501_pt2_one_pt25.png" path="evt_sel_jet_005501_pt2_one_pt25.png" size="22185" stream="evt_sel_jet_005501_pt2_one_pt25.png" user="Main.PatRyan" version="1"
>
>
META FILEATTACHMENT attachment="evt_sel_jet_005502_pt2_one_pt20.png" attr="" comment="" date="1175863848" name="evt_sel_jet_005502_pt2_one_pt20.png" path="evt_sel_jet_005502_pt2_one_pt20.png" size="22363" stream="evt_sel_jet_005502_pt2_one_pt20.png" user="Main.PatRyan" version="1"
Revision 10
Changes from r8 to r10
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Line: 48 to 48
 

-- PatRyan - 22 Feb 2007
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863741" name="evt_sel_jet_005500_pt2_one_pt25.png" path="evt_sel_jet_005500_pt2_one_pt25.png" size="23791" user="Main.PatRyan" version="1"
Added:
>
>
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863760" name="evt_sel_jet_005500_pt2_one_pt30.png" path="evt_sel_jet_005500_pt2_one_pt30.png" size="23780" user="Main.PatRyan" version="1"
 
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863714" name="evt_sel_jet_005500_pt2_one_pt20.png" path="evt_sel_jet_005500_pt2_one_pt20.png" size="23789" user="Main.PatRyan" version="1"
Changed:
<
<
META FILEATTACHMENT attachment="evt_sel_jet_005500_pt2_one_pt30.png" attr="" comment="" date="1175863759" name="evt_sel_jet_005500_pt2_one_pt30.png" path="evt_sel_jet_005500_pt2_one_pt30.png" size="23780" stream="evt_sel_jet_005500_pt2_one_pt30.png" user="Main.PatRyan" version="1"
>
>
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863777" name="evt_sel_jet_005501_pt2_one_pt20.png" path="evt_sel_jet_005501_pt2_one_pt20.png" size="22199" user="Main.PatRyan" version="1"
META FILEATTACHMENT attachment="evt_sel_jet_005501_pt2_one_pt25.png" attr="" comment="" date="1175863796" name="evt_sel_jet_005501_pt2_one_pt25.png" path="evt_sel_jet_005501_pt2_one_pt25.png" size="22185" stream="evt_sel_jet_005501_pt2_one_pt25.png" user="Main.PatRyan" version="1"
Revision 8
Changes from r6 to r8
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Line: 47 to 47
 

-- PatRyan - 22 Feb 2007
Changed:
<
<
META FILEATTACHMENT attachment="evt_sel_jet_005500_pt2_one_pt20.png" attr="" comment="" date="1175863714" name="evt_sel_jet_005500_pt2_one_pt20.png" path="evt_sel_jet_005500_pt2_one_pt20.png" size="23789" stream="evt_sel_jet_005500_pt2_one_pt20.png" user="Main.PatRyan" version="1"
>
>
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863741" name="evt_sel_jet_005500_pt2_one_pt25.png" path="evt_sel_jet_005500_pt2_one_pt25.png" size="23791" user="Main.PatRyan" version="1"
META FILEATTACHMENT attr="" autoattached="1" comment="" date="1175863714" name="evt_sel_jet_005500_pt2_one_pt20.png" path="evt_sel_jet_005500_pt2_one_pt20.png" size="23789" user="Main.PatRyan" version="1"
META FILEATTACHMENT attachment="evt_sel_jet_005500_pt2_one_pt30.png" attr="" comment="" date="1175863759" name="evt_sel_jet_005500_pt2_one_pt30.png" path="evt_sel_jet_005500_pt2_one_pt30.png" size="23780" stream="evt_sel_jet_005500_pt2_one_pt30.png" user="Main.PatRyan" version="1"
Revision 6
Changes from r4 to r6
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Line: 32 to 32
  For pTJet 2 > 25 GeV, a moderate number of events are removed, and for pTJet 2 > 20 GeV, amost no events are removed.
Added:
>
>
| evt_sel_jet_005501_pt2_one_pt30.png" | evt_sel_jet_005501_pt2_one_pt25.png" | evt_sel_jet_005501_pt2_one_pt20.png" |
 

Background Samples

The effects of different Jet 2 pT cuts on a Wbb background sample was also studied since a major role of this cut is to limit contamination from soft jets in the background. However, in the t-channel, the Wbb is probably not a significant background, and in the s-channel, the requirement that NJets ≥ 2 removes Wbb background, so lowering the pT cut to obtain more signal events would probably be a good idea regardless of its direct effect on the background.
Changed:
<
<
Plots of the Wbb FastSim sample are shown below for pTJet 2 > 30 GeV, pTJet 2 > 25 GeV,
>
>
Plots of the Wbb FastSim sample are shown below for pTJet 2 > 30 GeV, pTJet 2 > 25 GeV,
  and pTJet 2 > 20 GeV. It can been seen that as the cut is lowered, more events remain in the sample.

-- PatRyan - 22 Feb 2007 \ No newline at end of file
Added:
>
>
META FILEATTACHMENT attachment="evt_sel_jet_005500_pt2_one_pt20.png" attr="" comment="" date="1175863714" name="evt_sel_jet_005500_pt2_one_pt20.png" path="evt_sel_jet_005500_pt2_one_pt20.png" size="23789" stream="evt_sel_jet_005500_pt2_one_pt20.png" user="Main.PatRyan" version="1"
Revision 4
Changes from r2 to r4
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

Added:
>
>

Current Single Top Preselection

  The followin event selection is based upon that proposed by Arnaut Lucotte.
Added:
>
>
It is the most general event selection applied to single top samples and is refined further when selecting for specific channels (s, t or Wt).
 
Changed:
<
<

Lepton Selection

>
>

Lepton Selection

 
  • At least 1 high-pT lepton (e or μ)
    • Electron pT > 25 GeV
    • Muon pT > 20 GeV
  • No secondary lepton (e or μ) with both
    • pT > 10 GeV
    • -1.475 < η < 1.475
Changed:
<
<

Jet Selection

  • NJet ≥ 2, where the 2 jets have pT > 30 GeV
>
>

Jet Selection

  • NJet ≥ 2, where the Jet 1 has pT > 30 GeV and Jet 2 has pT > 25 GeV
 
  • NB-Jet ≥ 1; where the 1 B-jet has pT > 35 GeV
Changed:
<
<

Other Selection Criteria

>
>

Other Selection Criteria

 
  • ETMiss > 25 GeV
Added:
>
>

Investigation of the Jet 2 pT cut

Signal Samples

In the original event preselection, the pT cut on both jets was 30 GeV. However, requiring that the Jet 2 pT was greater than 30 GeV removed a disproportionatly large number of events when compared to the other selection criteria. Different values of this cut on signal and background samples were studied to see if more signal events could be obtained without drastically increasing the background.

Distributions of Jet 2 pT for s, t, and Wt channels are shown below. The plots on the left are for pTJet 2 > 30 GeV, the center plots are pTJet 2 > 25 GeV, and the plots on the right are for pTJet 2 > 20 GeV. For pTJet 2 > 30 GeV, it can be seen in all channels that a large number of events, as represented by the light blue are, are removed. For pTJet 2 > 25 GeV, a moderate number of events are removed, and for pTJet 2 > 20 GeV, amost no events are removed.

Background Samples

The effects of different Jet 2 pT cuts on a Wbb background sample was also studied since a major role of this cut is to limit contamination from soft jets in the background. However, in the t-channel, the Wbb is probably not a significant background, and in the s-channel, the requirement that NJets ≥ 2 removes Wbb background, so lowering the pT cut to obtain more signal events would probably be a good idea regardless of its direct effect on the background.

Plots of the Wbb FastSim sample are shown below for pTJet 2 > 30 GeV, pTJet 2 > 25 GeV, and pTJet 2 > 20 GeV. It can been seen that as the cut is lowered, more events remain in the sample.
 

-- PatRyan - 22 Feb 2007 \ No newline at end of file
Revision 2
02 Mar 2007 - PatRyan
Line: 1 to 1
 
META TOPICPARENT name="WebHome"

Single Top Event Selection

The followin event selection is based upon that proposed by Arnaut Lucotte.
Line: 7 to 7
 
  • At least 1 high-pT lepton (e or μ)
    • Electron pT > 25 GeV
    • Muon pT > 20 GeV
Changed:
<
<
  • No central lepton (e or μ) with pT > 10 GeV
>
>
  • No secondary lepton (e or μ) with both
    • pT > 10 GeV
    • -1.475 < η < 1.475
 

Jet Selection

  • NJet ≥ 2, where the 2 jets have pT > 30 GeV
 
This site is powered by FoswikiCopyright © by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding Foswiki? Send feedback