search for the higgs h o ->zz*->bbll philip davis (nmsu) mentor: dr. teuscher (u of t) aided...
TRANSCRIPT
Search For the Higgs Ho ->ZZ*->bbll
Philip Davis (NMSU)Mentor: Dr. Teuscher (U of T)Aided by Christophe Le Maner (U of T)
Invariant Mass of Higgsfor mH of 150 GeV before Cuts
Electron (shown) and Muon System Luminosity 30 fb-1
Mass Analysis on mH of 150 GeV
tt ZZ Zbb bb Zee Zmm
Higgs SignalBack Grounds
Intro
Previous analysis of this decay channel done by Christophe Le ManerMonte Carlo Data created using Pythia,
MCatNLO, and AcerMC New Monte Carlo Data simulated after first
analysis What I did
Try to recreate old analysisApply my own analysisCreate automated system of applying cuts
Cuts for mH of 150 GeV on Electron Channel (Previous Analysis)
Cut Value
Zero total charge on lepton pair Charge e1 + e2 = 0
Inv. Mass of Virtual Z System 10 < mZ < 65 GeV
Inv. Mass of Z System 50 < mZ < 110 GeV
η1 and η2 of VBF jets opposite dir. η1*η2 < 0
Diff. in pseudo rapidity of VBF jets |∆η| > 3.3
Mass of VBF jets mjj > 300 GeV
Missing Pt Ptmiss < 25 GeV
b jet and lepton in between VBF jets
Mass window 130 < mH < 170 GeV
Repeating Previous Analysis (New Data) Higgs Mass S S/√BG Relative Error
H130 (ee channel) 0.246 0.025 25.88%
H150 (ee chanel) 0.901 0.0812 20.63%
H130 (μμ chanel) 0.209 0.027 33.59%
H150 (μμ chanel) 0.877 0.0938 25.10%
Previous Analysis - Christophe Le Maner
Higgs Mass S S/√BG
H130 (ee channel) 0.14 0.057
H150 (ee chanel) 0.79 0.227
H130 (μμ chanel) 0.13 0.052
H150 (μμ chanel) 0.75 0.18
Cuts for mH of 150 GeV on Electron Channel
Cut Value
2 b-jets required
Invariant mass of di-electron System
10 < mee < 65 GeV
Missing Pt Pt < 25 GeV
Diff. in pseudo rapidity of VBF jets |∆η| > 3.3
Sum of Pt of VBF Jets Pt 1 + Pt 2 > 90 GeV
Mass of VBF jets mjj > 300 GeV
η1 and η2 opposite dir. η1*η2 < 0
Inv. Mass of Z System 50 < mZ < 110 GeV
Zero total charge on lepton pair Charge e1 + e2 = 0
Mass window 130 < mH < 170 GeV
Histograms
Gev
• 50 < mzo < 110 GeV •10 < mee < 65 GeV•(constrain leptons to come from Virtual Z)
Missing Pt < 25 GeV
GeV
Mass of VBF jets > 300 GeV
GeV
More Histograms
Pt of Forward Jet 1 Vs. Jet 2 Sum > 90 GeV
Pt
of 2
jet
(GeV
)
Pt of 1 jet (GeV)
New Cuts
Higgs Mass S S/√BG Relative Error
H130 (ee channel) 0.232 0.0339 39.57%
H150 (ee chanel) 0.882 0.103 28.23%
H130 (μμ chanel) 0.207 0.032 41.64%
H150 (μμ chanel) 0.878 0.116 31.13%
•Problem with H130 data is that it start out with low number of events•Increase in S/√BG from old cuts•Increase in Relative Error from old cuts•H150 data gives better results but still low significance
•Signal Rejection ~ 21% (H150 ee chanel)
•Background Rejection ~ 0.028% (H150 ee chanel)
Signal after Cuts
Higgs Signal
Fully Automated Cut System Program run cuts over a range of values
and stores results to root file. Results searched my another program to
return cuts with best outputs. Only used old data on this program.
Relative Error usually about 100%Next step should be to uses this method on
new data
Protection Circuit for LVPS
Background
Front end electronics of the Tile Calorimeter in ATLAS are kept in drawers as seen above.
TileCal has 256 of these drawers Each drawer requires its own power supply.
Background/Problem
The Low Voltage Power Supply (LVPS) converts a 200 V DC power supply to 8 DC voltages required by the front end electronics in the TileCal.
When installed in the pit the LVPS has burned up components due to voltages going over their ratings.
Important issue for LHCC
Solution
Regulating Circuit that monitors the 8 voltages and currents going to the detector. Monitors for under-voltage, over-voltage, and over-current.
Circuit switches power off in TileCal when voltage or current goes out of range.
Voltages put into two groups. High Voltage side and Digitizer side.
High Voltage When one side is triggered the other side can still operate.
Circuit Simulation
Circuit simulated in Quartus II Implemented in Embedded Local Monitor
Board (ELMB) in the LVPS
Circuit Explanation
Redundancy circuit
32 bit Shift Register
Current inputVoltage input
TripOutputs
Wave form of Inputs and OutputsOutputs of Digitizer and High Voltage Trigger
Output of Shift Register
Special Thanks
Dr. Teuscher Christophe Le Maner CERN University of Michigan NSF Ford
Backup slides
Cut Table
Cuts with weights for Muon Channel
Cut mH tt Zbb ZZ Zee Zmm bb Total BG Signal/sqrt(BG)Total number of events 3.62164 37159.4 15123.9 48.7148 8802.7 8911.03 176032 246078 0.00730077Total number bjets 3.39871 35726.3 14185.7 45.2463 0 8818.64 58677.3 117453 0.00991704invariant mass of muons 2.29167 13948.1 773.376 5.44377 0 6.70331 29338.7 44072.3 0.0109161missing pt 1.97626 1040.72 666.76 4.52534 0 4.66317 29338.7 31055.3 0.0112144Delta of eta for VBF jets 1.97626 1040.72 666.76 4.52534 0 0.874345 0 1712.88 0.0477508sum pt of vbf jets 1.31479 346.523 223.073 0.527201 0 0 0 570.124 0.0550644mass of vbf jets 1.28302 316.69 209.131 0.474719 0 0 0 526.296 0.0559266eta1*eta2<0 1.28302 316.69 209.131 0.474719 0 0 0 526.296 0.0559266zed mass 1.07471 81.4673 83.6525 0.372142 0 0 0 165.492 0.0835418even charge 1.07415 78.025 83.6525 0.372142 0 0 0 162.05 0.0843803mass window 0.87793 19.5063 37.7256 0.145517 0 0 0 57.3774 0.115902
Cuts with weights for Electron Channel
Cut mH tt Zbb ZZ Zee Zmm bb Total BG Signal/sqrt(BG)Total number of events 4.19315 41968.3 19334.4 64.86 8802.7 8911.03 176032 255113 0.00830183number of bjets 3.92187 40309.1 18031.2 59.891 8723 0 117355 184478 0.00913106invariant mass of electrons 2.63913 16928 1034.99 7.46192 55.3264 0 9338.7 47364.4 0.0121265missing pt 2.05103 1380.35 815.202 5.61553 49.5229 0 0 2250.7 0.0432329Delta of eta for VBF jets 2.05103 1380.35 815.202 5.61553 5.41657 0 0 2206.59 0.0436628sum pt of vbf jets 1.35695 481.919 245.217 0.517659 0.386898 0 0 728.041 0.0502907mass of vbf jets 1.32322 441.759 218.973 0.436551 0 0 0 661.169 0.0514607eta1*eta2<0 1.32322 441.759 218.973 0.436551 0 0 0 661.169 0.0514607zed mass 1.09917 115.89 91.0336 0.34113 0 0 0 207.265 0.0763487even charge 1.0972 102.121 90.2135 0.331588 0 0 0 192.666 0.0790467mass window 0.881866 33.2754 39.3659 0.0978065 0 0 0 72.7391 0.1034
Output of HV and Digitizer Pins
Wave of output pins Shows that each input works and that the
corresponding output pin is triggered.