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.