Beyond the Standard Model at the LHC Henri Bachacou on behalf of the ATLAS and CMS Collaborations Latsis Symposium 3-6 June 2013 Zurich, Switzerland
BSM at the LHC: Introduction The past two years have been extremely exciting The past two years have been extremely exciting Context for searches Beyond the Standard Model: Context for searches Beyond the Standard Model: → A Standard Model-looking Higgs boson has been discovered! → A Standard Model-looking Higgs boson has been discovered! → No sign of SUSY yet → No sign of SUSY yet → Exotic searches have never been more relevant → Exotic searches have never been more relevant In this talk I will focus on a selection of non-SUSY BSM In this talk I will focus on a selection of non-SUSY BSM searches at ATLAS and CMS searches at ATLAS and CMS → Focus on latest results based on (a fraction of) 8 TeV 2012 data → Focus on latest results based on (a fraction of) 8 TeV 2012 data → Many analyses are still work-in-progress → Many analyses are still work-in-progress Not showing all results from both experiments. Complete Not showing all results from both experiments. Complete information about all results: information about all results: → CMS: https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResults → CMS: https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResults → ATLAS: https://twiki.cern.ch/twiki/bin/view/AtlasPublic → ATLAS: https://twiki.cern.ch/twiki/bin/view/AtlasPublic H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 2
The Large Hadron Collider (LHC) pp collisions: → 5 fb -1 at √s = 7 in 2011 20 fb -1 → 20 fb -1 at √s = 8 TeV in 2012 LHC has performed extremely well in 2012: → 7.7 10 33 /cm 2 /s peak luminosity → More than 20 fb -1 delivered to both experiments 50 ns bunch spacing Pile-up: ~ 20 collisions / crossing H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 3
The ATLAS and CMS Detectors: same goals, different choices CMS 3.8T solenoid containing calorimeters Silicon tracker: σ(p T )/p T ~ 15% at 1TeV EM cal: homogeneous Lead-Tungstate o crystal, σ E /E ~ 3%/√E[GeV] 0.5% + HAD cal: Brass-scint., ≥7λ 0 o + σ E /E ~ 100%/√E[GeV] 5% o Iron return yoke muon spectrometer 2T solenoid inside calorimeters Tracker: Silicon + TRT (incl. electron ID) EM cal: Longitudinally segmented Lead-Ar: o + σ E /E ~ 10%/√E[GeV] 0.7% HAD cal: Fe-scint + Cu-Ar, ≥11λ 0 o σ E /E ~ 50%/√E[GeV] 3% + ATLAS Air-toroid muon sp.: ⌡√B.dl = 1 to 7 T.m H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 4
Why look “beyond” the Standard Model? The Standard Model is a (very) effective theory that breaks down at a certain scale → Hierarchy: quadratic divergence of the Higgs mass, extremely fine-tuned → What is the underlying nature of EWSB? Dark Matter → cannot be explained by SM BSM models attempt to solve the SM limitations: → SUSY → Extra-dimensions → Compositeness and Strong Interactions → ... H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 5
A very long list of models x signatures Many extensions of the SM have been 1 jet + MET jets + MET developed over the past decades: 1 lepton + MET Supersymmetry Same-sign di-lepton Extra-Dimensions Dilepton resonance Diphoton resonance Technicolor(s) Diphoton + MET Little Higgs Multileptons Lepton-jet resonance No Higgs Lepton-photon resonance GUT Gamma-jet resonance Diboson resonance Hidden Valley Z+MET Leptoquarks W/Z+Gamma resonance Top-antitop resonance Compositeness Slow-moving particles 4 th generation (t', b') Long-lived particles LRSM, heavy neutrino Top-antitop production Lepton-Jets What else? Microscopic blackholes Dijet resonance What else? (for illustration only) H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 6
A very long list of models x signatures Many extensions of the SM have been 1 jet + MET A complex 2D jets + MET developed over the past decades: problem 1 lepton + MET Supersymmetry Same-sign di-lepton Experimentally, Extra-Dimensions Dilepton resonance a signature Diphoton resonance Technicolor(s) standpoint Diphoton + MET Little Higgs Multileptons makes a lot of Lepton-jet resonance No Higgs sense: Lepton-photon resonance GUT Gamma-jet resonance → Practical Diboson resonance Hidden Valley → Less model- Z+MET Leptoquarks W/Z+Gamma resonance dependent Top-antitop resonance Compositeness → Important to Slow-moving particles 4 th generation (t', b') Long-lived particles cover every LRSM, heavy neutrino Top-antitop production possible Lepton-Jets What else? signature Microscopic blackholes Dijet resonance What else? (for illustration only) H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 7
Grand summary: Grand Summary H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 8
Grand summary: Grand Summary H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 9
Outline th generation and Heavy Resonances 4 heavy “quarks” → Dilepton → Vector-like quarks → Dijet → Top-Antitop Long-lived particles TeV-gravity and Dark and more exotic final Matter states → Monojets → Stopped particles → Exotic Higgs decays H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 10
Outline th generation and Heavy Resonances 4 heavy “quarks” → Dilepton → Vector-like quarks → Dijet → Top-Antitop Long-lived particles TeV-gravity and Dark and more exotic final Matter states → Monojets → Stopped particles → Exotic Higgs decays H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 11
Search for Heavy Resonance Predicted by numerous extensions of the Standard Model: → Heavy gauge boson(s) Z' (W'): GUT-inspired theories, Little Higgs → Kaluza-Klein excitations: Randall-Sundrum extra-dimensions Experimental challenge: understand detector performance (resolution, efficiency) for a signal with (almost) no control sample at very high momentum → confidence in alignment, simulation, etc... Electrons and muons: reaching pT ~ 1 TeV! H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 12
Search for Heavy Resonance: dilepton channel Dimuon channel: → 30 μm muon spectrometer alignment critical (ATLAS) → Resolution 10-15% at p T = 1 TeV Dielectron channel: → Excellent resolution: < 2% at high m( μ + μ - ) [GeV] momentum → Poor charge measurement → no charge requirement No discrepancy from SM Drell- Yan (both ATLAS and CMS) m(ee) [GeV] [ATLAS-CONF-2013-017] H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 13
Search for Heavy Resonance: dilepton channel m(μμ) = 1.84 TeV H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 14
Search for Heavy Resonance: dilepton channel Sequential SM: assume Z' with same couplings as SM Z Sequential SM: assume Z' with same couplings as SM Z Randall-Sundrum KK graviton Randall-Sundrum KK graviton Model ATLAS CMS SSM Z’ 2.86 2.96 Observed lower limits (TeV) at 95% CL: E6 Z’ Ψ 2.38 2.60 RS G* (k/M pl = 0.1) 2.47 [ATLAS-CONF-2013-017] [CMS PAS EXO-12-061] H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 15
Search for Heavy Resonance: W' → lv W': the charged equivalent of the Z' Bulk-RS: excited KK W Final state: 1 lepton + Missing E T Look for Jacobian peak in transverse mass: Electron channel [CMS PAS EXO-12-060] H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 16
Search for Heavy Resonance: W' → lv W': the charged equivalent of the Z' Bulk-RS: excited KK W Final state: 1 lepton + Missing E T Look for Jacobian peak in transverse mass: Muon channel [CMS PAS EXO-12-060] H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 17
Search for Heavy Resonance: W' → lv W': the charged equivalent of the Z' Bulk-RS: excited KK W Final state: 1 lepton + Missing E T Look for Jacobian peak in transverse mass: Sequential SM: m(W') > 3.35 TeV at 95% C.L. Muon channel [CMS PAS EXO-12-060] H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 18
Search for Heavy Resonance: Dijet W'/Z', excited quarks, strong gravity CMS 20 fb -1 @ 8 TeV [EXO-12-059] Look for resonance above phenomenological fit of the data: ATLAS versus CMS analysis in a nutshell: → 1-jet triggers E T ~350 GeV vs H T /m(jj) at HLT → anti-k T R=0.6 jets vs wide jets (R~1.1) Both Experiments: → rapidity cuts to enhance central scattering → selection requires m(jj) ≳ 1 TeV H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 19
Search for Heavy Resonance: Dijet W'/Z', excited quarks, strong gravity ATLAS 13 fb -1 @ 8 TeV [CONF-2012-148] Look for resonance above phenomenological fit of the data: ATLAS versus CMS analysis in a nutshell: → 1-jet triggers E T ~350 GeV vs H T /m(jj) at HLT → anti-k T R=0.6 jets vs wide jets (R~1.1) Both Experiments: → rapidity cuts to enhance central scattering → selection requires m(jj) ≳ 1 TeV H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 20
Search for Heavy Resonance: Dijet Highest mass dijet event with central jets: m(jj) = 5.15 TeV H. Bachacou, Irfu CEA-Saclay Latsis, 3-6/06/2013 21
Recommend
More recommend
