Lepton Reconstruction and. Steven Goldfarb MCTP: LHC New Physics Signatures Workshop University of Michigan, Ann Arbor - 5 Jan 2008

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1 New Physics at the LHC: Lepton Reconstruction and Signatures in and Steven Goldfarb MCTP: LHC New Physics Signatures Workshop University of Michigan, Ann Arbor - 5 Jan 2008

2 The LHC: By Numbers Nominal Operating Parameters (p-p) E injection = 450 MeV E beam = 7 TeV L = cm -2 s -1 Bunch Spacing = 25 ns (40 MHz) Pile-Up = 2-20 collisions/crossing Collision Duration h Down Time h Lifetime (as is) 10 y (when statistical error half-life = 5y) MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 2

3 The LHC: Coming Years Current Schedule April Machine Closed May Beam Commissioning at 7 TeV July First Collisions at 14 TeV (aim for cm -2 s -1 by end 2008) 2008 Stage I II III Hardware commissioning 7TeV Machine checkout 7TeV Beam commissioning 7TeV 43 bunch operation 75ns ops 25ns ops I Shutdown 2009 No beam Beam III Shutdown Machine checkout 7TeV Beam setup 25ns ops I Install Phase II and MKB No beam Beam MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 3

4 The LHC: Physics Physics in the First Year At L = cm -2 s -1 and 50% data-taking taking efficiency (early on) few weeks 100 pb -1 6 months 1 fb -1 Example Decay Channel LEP Tevatron LHC LHC (all) (all) (100 pb -1 ) (1 fb -1 ) W μν ~10 4 ~10 6 ~10 6 ~10 7 Z μμ ~10 6 ~10 5 ~10 5 ~10 6 tt WbWb μν+ X ~10 4 ~10 4 ~10 5 QCD jets (p >1TeV) T ~10 3 ~10 4 g g (1 TeV) q qzχ ~50 ~10 3 Z (1 TeV) μμ ~20 ~10 2 H (160 GeV) WW* lνlν 5σ? F. Gianotti, D. Froidevaux (a few additions by me) MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 4

5 The LHC: Leptonic Signatures of New Physics Why Leptons? 1. That s what you asked me to present. 2. Michigan has a key role in the construction, operation of Precision Muon Chambers 3. Lepton signatures are clean (easy to trigger, select, low non-physics background) 4. Excellent for benchmarking, calibrating, aligning (Z, W, J/ψ, ) So we will be tagging and measuring them, anyway 5. History Neutral Currents in Gargamelle J/ψ Decays in E288 Υ Decays in E288 Z Decays in UA1 & UA2 MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 5

6 The LHC: Leptonic Signatures of New Physics The LHC Lepton Shopping List Standard d Model Higgs GMSB ( (χ 0 1 G Gγ, l R G l) Gl) H ZZ llll χ 20 l l R llχ 1 0 llg γ H WW lνlν Right-Handed W qqh qqττ (one or both τ lνν) W R l + N l + ljj MSSM Higgs Excited & Heavy Leptons gg bbh(a), H(A) ττ,μμ pp ll llz l + ljj (resonances) Doubly Charged Higgs gg Z,Z LL lz + lz ljj + ljj H ±± W ± W ± l ± νl ± ν Technicolor Massive Vector Bosons (KK, Gravitons, etc.) ρ TC WZ lllν Z,G ll Et Cetera Z,G WW lνlνl SM precision measurements, e.g. W lν or WZ SUSY g Allergy Note: Notice: qq L L The I focused ingredients here contain primarily significant leptonic traces final states. of hadronic Leptons byproducts, of heavy event quarks, pile-up, for and example, cavern is background. not q L qχ 20 ql l R qllχ 1 0 as tags presented. MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 6

7 & : Detector Overview LHC Properties Weight 7000 tons 12,500 tons Diameter 22m 15m Length 46m 22m B Field 2T solenoid 3.9T (peak) BA toroid 4.1T (peak) EC toroids 4T solenoid MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 7

8 & : Detector Overview Primary Characteristics (Compact Muon Solenoid) (A Toiroidal Lhc ApparatuS) Large 4T Solenoid Small 2T Solenoid for Tracking Muon Chambers Integrated in 3 Large Toroids for Muon Spectroscopy Return Yoke High BL 2 for Standalone Muon Spectrometer Measurements Precision: Drift Tubes, CSC Muon Spectrometer Trigger: RPC Precision: MDT, CSC Primary Measurements from Tracker Trigger: RPC, TGC Calorimetry Excellent acceptance at poles PbWO 4 Crystal: Excellent Calorimetry Resolution, Lateral Segmentation ti Lateral & Longitudinal Segmentation FCAL 11.2m from IP FCAL only 4.9m from IP Inner Tracking Inner Tracking (Pixel, SCT, TRT) Pixels: 100μm (r-φ) x 150μm (z) Pixels: 50μm (r-φ) (rφ) x 400μm (z) Δp/p (1 GeV) = 0.007,0.02 (η 0,2.5) Δp/p (1 GeV)= 0.013,0.02 (η 0,2.5) Δp/p (100 GeV) = 0.015,0.07 Δp/p (100 GeV) = 0.038,0.11 Excellent momentum resolution TRT for e/π identification MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 8

9 & : Detector Characteristics Tracking Detectors Tracker Parameters Solenoid B-Field 2T 4T Outer Dimensions (r / z) 115cm / 700cm 110cm / 540cm Coverage (η) ±2.5 ±2.5 Technologies ooges Si Pixels (140,000,000) Si Pixels (66,000,000) Si Microstrips (6,2000,000) Si Microstrips (9,600,000) Straw Tubes (420,000) Elements Crossed by Track 3 pixels, 8 strips, 36 straws 3 pixels, strips (barrel) 2 pixels, strips (endcap) Material Crossed by Track 0.35X X X X 0 Pixel resolution (r-φ / z) 12 μm / 66 μm (barrel) 10 μm / 20 μm 12 μm / 77 μm (endcap) MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 9

10 & : Detector Characteristics Electromagnetic & Hadronic Calorimeters Calorimeter Parameters Outer Dimensions (r / z) Coverage (η) ECAL Technology 2.25m / ±6.65m (ECAL) 4.25m / ±6.10m (HCAL) ±3.2 (ECAL, HCAL) ±4.9 (FCAL) Presampler Pb / LAr (Liquid Argon) Accordion (190,000) HCAL Technology Fe / Scintillator (10,000) Cu / LAr (HEC) Cu / W / LAr (FCAL) Samplings Material Resolution (η / φ) (Barrel) (1) (Endcap) (Forward) 24 X 0-26 X 0 (ECAL) 11 λ (HCAL) 1.8m / ±3.8m (ECAL) 2.9m / ±5.6m (HCAL) ±3.0 (ECAL, HCAL) ±5.0 (FCAL) Preshower (π 0 rejection) PbWO 4 Crystals (68,500) Iron / Quartz Fiber Brass / Scintillator Scintillator (HO) Steel / Quartz-Fiber (HF) (Barrel) (Endcap) (Forward) 25 X 0 (ECAL) 7-11 λ (HCAL) / mrad (ECAL) / mrad (ECAL) / mrad (HCAL) / mrad (HCAL) MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 10

11 & : Detector Characteristics Muon Spectrometers Spectrometer Parameters B Field 3 Toroids (B = T) Solenoid (B = 2.0T) Outer Dimensions (r / z) 11m / ±12.5m (barrel) 11m / ±23m (endcap) 7.4m / ±6.4m (barrel) 7m / ±11m (endcap) Measuring Coverage (η) ±2.7 ±2.4 Ti Trigger Coverage (η) ±2.4 ±2.1 Technologies Monitored Drift Tubes Cathode Strip Chambers Resistive Plate Chambers Drift Tubes ( η < 1.2) Cathode Strip Chambers Resistive Plate Chambers Thin Gap Chambers Precision Measuring Layers 3 (Barrel) 4 (Endcap) 4 (Barrel) 3-4 (Endcap) Material non-uniform ~170 X 0 (mainly negligible) Resolution (η / φ) 40 μm (η) (MDT chamber) 60 μm (η) (CSC single wire) 100 μm (φ) (DT chamber) 200 μm (φ) (CSC chamber) MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 11

12 & : Electron Reconstruction Electron ID and Reconstruction 1. Build clusters from ECAL cells 2. Correct for geometry effects 3. Correct for cell saturation 4. Match clusters to tracks 5. Correct for bremsstrahlung 6. Require isolation 7. Physics cuts MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 12

13 & : Muon Reconstruction Outside-In 1. Build segments in stations 2. Build tracks from hits or segments 3. Correct for E loss & multiple scattering 4. Match to calorimeter, inner tracker 5. Combine statistically or re-fit Inside-Out 1. Start with tracks in inner tracker 2. Match with Calorimeter Deposits 3. Match with Hits, Segments, Tracks in Spectrometer MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 13

14 & : Tau Reconstruction Hadronic Decays 1. Localized energy deposits in calorimeters 2. Require hadronic energy 3. Match with 1 or 3 tracks in cone 4. Remove photon conversion tracks 5. Require isolation in calorimeters 6. Require small jet mass Leptonic Decays 1. Isolated electron or muon, missing E T MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 14

15 & : Detector Performance Tracking η 0 η η 0 η δp/p at p T = 1 GeV 1.3% 2.0% 0.7% 2.0% δp/p at p T = 100 GeV 3.8% 11.0% 1.5% 7.0% ε(pions) at p T = 1GeV 84.0% 80% ε(electrons) at p T = 5 GeV 90.0% 85.0% Calorimetry ECAL δe/e (100 GeV Photons) 1-1.5% 0.8 % ECAL δe/e (50 GeV Electrons) % 2.0 % ECAL+HCAL Stochastic Term 55% / E 70% / E ECAL+HCAL Constant Term 2.3% 8.0% Muon Spectrometry Standalone Combined Standalone Combined η 0 η 2 η 0 η 2 η 0 η 2 η 0 η 2 δp/p at p = 10 GeV 3.9% 6.4% 1.4% 2.4% 8% 11% 0.8% 2.0% δp/p ppat p = 100 GeV 3.1% 3.1% 2.6% 2.1% 9% 18% 1.2% 1.7% δp/p at p = 1000 GeV 10.5% 4.6% 10.4% 4.4% 13% 35% 4.5% 7.0% MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 15

16 & : Detector Performance Cosmic Ray Commissioning Performance Tests Example: Combined Run in 2007 Integrated runs taking data from all major detector components Example here for Muon Spectrometer Endcap Performance MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 16

17 The LHC: Leptonic Signatures of New Physics The LHC Lepton Shopping List Standard d Model Higgs GMSB ( (χ 0 1 G Gγ, l R G l) Gl) H ZZ llll χ 20 l l R llχ 1 0 llg γ H WW lνlν Right-Handed W qqh qqττ (one or both τ lνν) W R l + N l + ljj MSSM Higgs Excited & Heavy Leptons gg bbh(a), H(A) ττ,μμ pp ll llz l + ljj (resonances) Doubly Charged Higgs gg Z,Z LL lz + lz ljj + ljj H ±± W ± W ± l ± νl ± ν Technicolor Massive Vector Bosons (KK, Gravitons, etc.) ρ TC WZ lllν Z*,Z,G ll Et Cetera Z,G WW lνlνl SM precision measurements, e.g. W lν or WZ SUSY g qq L L q L qχ 20 ql l R qllχ 1 0 MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 17

18 The LHC: Standard Model Higgs SM Higgs Production & Decay at LHC Hardest place to look: M H < 130 GeV (but, possible with time) Easiest place to look: M H = 160 GeV (discovery through WW, perhaps) MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 18

19 The LHC: Standard Model Higgs Discovery Potential MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 19

20 The LHC: Standard Model Higgs The Golden Channel: H ZZ μμμμ, μμee, eeee Not the first, but best for precision measurements Effective channel for 120 < M H < 700 GeV Cuts on lepton quality, isolation H μμμμ MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 20

21 The LHC: Standard Model Higgs The Discovery Channel?: H WW lνlν High rate near M H = 160 GeV Spin correlations give small angle between leptons Main background from WW production, and tt (also ZZ llνν) Can only measure m T M. Dührssen et al., M H =150GeV M H =170GeV MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 21

22 The LHC: Standard Model Higgs Vector Boson Fusion: qqh qqττ Two jets at high rapidity Tag one τ with a lepton MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 22

23 The LHC: MSSM Higgs H/A ττ Early H ττ probably MSSM (SM production too low) At low tanβ, gg A ττdominates At high tanβ, bbh and bba associated production boosts signal H/A μμ Need H > 100 GeV to avoid Z ττ background Tag one τ with a lepton Tagging b in associated production greatly reduces Z ττbackground Lower rates less background better resolution MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 23

24 The LHC: Massive Vector Bosons Z μμ, ee Anything massive decaying to oppositely charged leptons of same flavor Kaluza-Klein Z excitations, K-K Graviton excitations (Randall-Sundrum), GUT, Selected exactly two isolated electrons or muons Apply minimal E T or p T cuts A hard photon or two is acceptable MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 24

25 The LHC: SUSY (msugra Example) g qq L q L q L qχ 20 ql l R l R qllχ 10 1 (assuming m(g ) m(g) m(q ) m(q) atlm1) Cascade decay of squarks and gluinos Look for high p T isolated leptons, high p T jets and missing E T Expect triangular shape of di-lepton mass Subtract background from different-flavor opposite-sign lepton pairs Studies typically focus on msugra to determine discoverability different-flavor subtraction MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 25

26 The LHC: Excited W Bosons W eν Resonance appearing high P T of standard W production W WZ Main background from continuum of WZ production (or ZZ, missing lepton) Look for 3 charged leptons, missing E T Two leptons from Z (same flavor, opposite charge) Remove tt background with lepton isolation cuts MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 26

27 The LHC: Technicolor ρ TC WZ lνll Model: multiscale technicolor SU(N TC ), N TC =4, 2 isotriplets of π TC Same recipe as for W, but lower mass Angular distribution sensitive to polarization MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 27

28 Summary Leptons in the LHC LHC Discovery Channels Primarily Leptonic Clean signals, easy to identify, measure & Optimized to Identify and Measure Leptons Majority of $550M price tags went to Magnets, Spectrometry Both detectors provide outstanding performance in resolution, efficiency Readiness The Detectors are both more than 90% installed Small Wheel Installation scheduled next week in similar situation Test Beam, Cosmic Commissioning Successful Detectors working essentially as expected Steve s Predictions Major Hurdles in Accelerator & Detector Debugging: These are complex devices. Computing: These are also complex devices. Discoveries in the first 2 years? The only question is What? MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 28

29 References & Credit Physics Technical Design Report, Vol. 1 (CERN/LHCC ) Physics Technical Design Report, Vol. 2 (CERN/LHCC ) 021) Physics Technical Design Report, Vols. 1 & 2 (CERN/LHCC ) The LHC Accelerator Complex, Jörg Wenninger (CERN-AB) AB), Hadron Collider Physics Summer School, FNAL, Jun Status and Schedule of LHC, Lyn Evans (CERN-LHC), Plenary, CERN, Oct Discovery Physics at the LHC, Andreas Hoecker (CERN-PH), XI Mexican Workshop on Particles and Fields, Tuxtla Gutierrez, Mexico, Nov Particle Detection and Reconstruction at the LHC (and Tevatron), Daniel Froidevaux (CERN-PH), Hadron Collider Physics Summer School, FNAL, Jun The Road to Discovery, Andy Parker (Cambridge University), Hadron Collider Physics Summer School, FNAL, Jun Search for Extra Dimensions and Leptoquarks in Early LHC Data, Greg Landsberg (Brown University), ILC/LHC Early Phase Workshop, FNAL, Apr New and Old Gauge Boson Discoveries in Early LHC Data, Gustaaf Brooijmans (Columbia University), ILC/LHC Early Phase Workshop, FNAL, Apr Impact of an Early Higgs Observation at the LHC on he ILC, Kyle Cramner (BNL), ILC/LHC Early Phase Workshop, FNAL, Apr Prospects for Higgs Boson Searches at the LHC, Karl Jakobs (University of Freiburg), SUSY 07, Karlsruhe. Coffee and Discussions with Karl Jakobs (University of Freiburg), Physics Coordinator. Correspondence with Physics Conveners: David Futyan, Pascal Vanlaer, Nicola Amapane, Simone Gennai. MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 29

30 Speaker Bias Disclaimer Participation Note that, although the speaker is an active member of the Collaboration, he has made every effort possible to present both and in a fair and non biased manner. That ends now. MCTP, Ann Arbor - 6 Jan 2008 S. Goldfarb - University of Michigan LHC Leptons - Slide 30

Introduction. Tau leptons. SLHC. Summary. Muons. Scott S. Snyder Brookhaven National Laboratory ILC Physics and Detector workshop Snowmass, Aug 2005

Introduction. Tau leptons. SLHC. Summary. Muons. Scott S. Snyder Brookhaven National Laboratory ILC Physics and Detector workshop Snowmass, Aug 2005 Leptons and Photons at the (S)LHC Scott S. Snyder Brookhaven National Laboratory ILC Physics and Detector workshop Snowmass, Aug 2005 Outline: Introduction. e/γ. Muons. Tau leptons. SLHC. Summary. Leptons