Upload
lee-stanley
View
215
Download
0
Embed Size (px)
DESCRIPTION
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 3 Higgs Physics Background on Why We Need the Higgs
Citation preview
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 1
H->H->
Jessica LeonardUniversity of Wisconsin -
MadisonPreliminary Examination
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 2
Standard modelStandard model
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 3
Higgs PhysicsHiggs PhysicsBackground on Why We Need the Higgs
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 4
The Higgs The Higgs tau tau tau tau signalsignal
Feynman diagramsWhy is it interesting? - Backgrounds: QCD 2 + 2/3j, EW 2 + 2j, t-tbar->WbWb, (b-bbar, Drell-Yan Z/* production,) W+jets
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 5
LHC!LHC!
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 6
Luminosity ProfileLuminosity Profile
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 7
Experiments at the LHCExperiments at the LHC
First Collisions 2007Physics in 2008
27 Km ring 1232 dipoles B=8.3 T(NbTi at 1.9 K)
TOTEM
ATLAS and CMS :pp, general purpose
LHCb : pp, B-physics
ALICE : heavy ions,p-ions
• pp s = 14 TeV Ldesign = 1034 cm-2 s-1
• Heavy ions (e.g. Pb-Pb at s ~ 1000 TeV)
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 8
CMS detector (temp CMS detector (temp slide)slide)
Components with slides already:ECAL, HCAL, tracker, trigger, muon
Should other components have slides?magnet, preshower, . . .
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 9
CMS DetectorCMS Detector
MUON BARREL
CALORIMETERS
PixelsSilicon Microstrips210 m2 of silicon sensors9.6M channels
ECAL76k scintillating PbWO4 crystals
Cathode StripChambers (CSC)Resistive PlateChambers (RPC)
Drift Tube Chambers (DT)
Resistive Plate Chambers (RPC)
Superconducting Coil,4 Tesla
IRON YOKE
TRACKER
MUONENDCAPS
HCALPlastic scintillator/brasssandwich
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 10
ECALECAL
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
ECAL crystals are PbWO4 - high density - small Moliere radius
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 11
HCALHCAL
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture. HCAL sampling calorimeter:50 mm copper plates and 4 mm scintillator tiles
HF extends coverage to |h| = 5Steel plates and 300 m quartz fibers
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 12
Muon SystemMuon System
Largest chambers of drift tubes 4 x 2.5 m
Cathode strip chambers use wires and strips to measure r and , respectively
Resistive plate chambers capture avalanche charge on metal strips
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 13
TrackerTracker
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Silicon strip detector used in barrel and endcaps
Silicon pixel detectorsused closest to the interactionregion
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 14
TriggerTrigger
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 15
Temp slideTemp slideSuggestions for text on detector component pages?
More detailed diagrams of different types of subcomponents, e.g. muon system? (RPC, DT, CSC)
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 16
H->H-> final states and final states and triggerstriggers
Note: Here “jet” means energy deposit consistent with
->jj•L1: single or double (93, 66 GeV) ???•HLT: double ???
->j•L1: single •HLT: single , + jet
->ej•L1: single isolated e, e + jet•HLT: single isolated e, e + jet
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 17
H->H->->l+->l++single-prong +single-prong event offline selectionevent offline selection
e and candidates identified•Additional electron requirements:•E/p > 0.9•Tracker isolation•Hottest HCAL tower Et < 2 GeV
Highest-pt lepton candidate with pt > 15 GeV chosen
Lepton track identifies the other tracks of interest: within z = 0.2 cm at vertex
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 18
H->H->->l+->l++single-prong +single-prong event offline selection event offline selection
(cont.)(cont.) candidates identified; jet formed around each and passed through t-tagging requirements
Require -jet charge opposite lepton charge
Hottest HCAL tower Et > 2 GeV if coincides with electron candidate
-jet Et > 30 GeV
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 19
H->H->->l+->l++single-prong +single-prong event offline selection event offline selection
(cont.)(cont.)Jets are the 2 highest-Et jets with Et > 40 GeV, not including e and candidate
Jets must be within || < 4.5, as well as having different signs in h
Require hj1j2 > 4.5, fj1j2 < 2.2, invariant mass Mj1j2 > 1 TeV
Require transverse mass of lepton-MisEt system < 40 GeV
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 20
H->H->->2 1-prong->2 1-prongBackgrounds: ttbar, Drell-Yan Z/*, W+jet, Wt, QCD multi-jet
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 21
H->H->->->+jet+jet
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 22
H->H->->e+jet->e+jet
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 23
Generate eventsGenerate events
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 24
My cutsMy cuts
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 25
PlotsPlots
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 26
What next?What next?
Jessica Leonard, U. Wisconsin, December 19, 2006 Preliminary Exam - 27
ConclusionsConclusions