The LHC and beyond. Georg Weiglein DESY. Cambridge, 08 / Introduction: on the way to the TeV scale. Physics at the LHC and future colliders

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1 The LHC and beyond Georg Weiglein DESY Cambridge, 08 / 2010 Introduction: on the way to the TeV scale Physics at the LHC and future colliders Electroweak symmetry breaking How to make dark matter visible at colliders? Example: Supersymmetry Conclusions The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.1

2 Introduction: on the way to the TeV scale 1TeV 1000 m proton m mev Temperature / Energy ev kev MeV GeV TeV Atomic physics Nuclear physics Particle physics Cathode ray tube Cyclotron LEP, SLC Tevatron ILC, LHC W, Z Higgs W, topz SUSY Higgs Extra Dimensions Inflation CMB BBN Baryogenesis photon Neutrino WIMP Decoupling Decoupling Decoupling Lambda Matter Radiation dominated now 10^17 10^12 10^6 1 Time (s) 10^ 6 10^ 12 The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.2

3 What can we learn from exploring the new territory of TeV-scale physics? How do elementary particles obtain the property of mass: what is the mechanism of electroweak symmetry breaking? Is there a Higgs boson (or more than one)? Do all the forces of nature arise from a single fundamental interaction? Are there more than three dimensions of space? Are space and time embedded into a superspace? What is dark matter? Can it be produced in the laboratory? Are there new sources of CP-violation? Can they explain the asymmetry between matter and anti-matter in the Universe?... The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.3

4 What is the mechanism of electroweak symmetry breaking? Standard Model (SM), SUSY,... : Higgs mechanism, elementary scalar particle(s) Strong electroweak symmetry breaking: anewkindofstronginteraction Higgsless models in extra dimensions: boundary conditions for SM gauge bosons and fermions on Planck and TeV branes in higher-dimensional space New phenomena required at the TeV scale The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.4

5 Higgs: last missing ingredient of the "Standard Model" But: the Standard Model cannot be the ultimate theory The Standard Model does not include gravity breaks down at the latest at M Planck GeV Hierarchy problem : M Planck /M weak How can two so different scales coexist in nature? Via quantum effects: physics at M weak is affected by physics at M Planck Instability of M weak Would expect that all physics is driven up to the Planck scale Nature has found a way to prevent this The Standard Model provides no explanation The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.5

6 Hierarchy problem: how can the Planck scale be so much larger than the weak scale? Expect new physics to stabilise the hierarchy Supersymmetry: Large corrections cancel out because of symmetry fermions bosons Extra dimensions of space: Fundamental Planck scale is TeV (large extra dimensions), hierarchy of scales is related to a warp factor ( Randall Sundrum scenarios) Attractive new physics scenarios address EWSB, hierarchy problem and provide viable dark matter candidate The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.6

7 Models with extra dimensions of space Hierarchy between M Planck and M weak is related to the volume or the geometrical structure of additional dimensions of space observable effects at the TeV scale The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.7

8 The Minimal Supersymmetric Standard Model (MSSM) Superpartners for Standard Model particles: [ u, d, c, s, t, b ] [ũ, d, c, s, t, b ] L,R [ e, µ, τ ] L,R L,R [ẽ, µ, τ ] L,R [ νe,µ,τ ] [ νe,µ,τ ] L Spin 1 2 L Spin 0 g W ±,H ± }{{} γ,z,h 0 1,H 0 2 }{{} Spin 1 /Spin0 g χ ± 1,2 χ 0 1,2,3,4 Spin 1 2 Two Higgs doublets, physical states: h 0,H 0,A 0,H ± General parametrisation of possible SUSY-breaking terms free parameters, no prediction for SUSY mass scale Hierarchy problem expect observable effects at TeV scale The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.8

9 Squark and slepton mixing ( M 2 t M t = + m 2 L t + M Z 2c 2β(Tt 3 Q ts 2 W) m t X q m t X q M 2 t R + m 2 t + M 2 Z c 2βQ t s 2 W ) m t 1,m t 2,θ t M b = ( M + m 2 bl 2 b + M Z 2 c 2β(Tb 3 Q bs 2 W) m b Xq ) m b X q M 2 br + m 2 b + M Z 2c 2βQ b s 2 W m b1,m b2,θ b with X q = A q µ κ, κ = {cot β,tan β} for q = t, b, tan β v u /v d Off-diagonal element is prop. to mass of partner fermion mixing important in t sector, for large tan β also in b, τ sect. The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.9

10 Squark and slepton mixing ( M 2 t M t = + m 2 L t + M Z 2c 2β(Tt 3 Q ts 2 W) m t X q m t X q M 2 t R + m 2 t + M 2 Z c 2βQ t s 2 W ) m t 1,m t 2,θ t M b = ( M + m 2 bl 2 b + M Z 2 c 2β(Tb 3 Q bs 2 W) m b Xq ) m b X q M 2 br + m 2 b + M Z 2c 2βQ b s 2 W m b1,m b2,θ b with X q = A q µ κ, κ = {cot β,tan β} for q = t, b, tan β v u /v d Gauge invariance M t L = M bl relation between m t 1,m t 2,θ t,m b1,m b2,θ b The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.10

11 Mass relations in the MSSM SM: all masses are free input parameters (except M W -M Z rel.) MSSM: Sfermion mass relations, e.g. m 2 ẽ L = m 2 ν L M 2 W cos(2β) Relations between neutralino and chargino masses Upper bound on mass of lightest CP-even Higgs boson All relations receive corrections from loop effects effects of soft SUSY breaking, ew symmetry breaking Experimental verification of parameter relations is a crucial test of SUSY! The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.11

12 How does SUSY breaking work? Exact SUSY m e = mẽ,... SUSY can only be realised as a broken symmetry MSSM: no particular SUSY breaking mechanism assumed, parameterisation of possible soft SUSY-breaking terms relations between dimensionless couplings unchanged cancellation of large quantum corrections preserved Most general case: 105 new parameters Strong phenomenological constraints on flavour off-diagonal and CP-violating SUSY-breaking terms Good phenomenological description for universal SUSY-breaking terms ( diagonal in flavour space) The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.12

13 Simplest ansatz: the Constrained MSSM (CMSSM) Assume universality at high energy scale (M GUT, M Pl,...) renormalisation group running down to weak scale require correct value of M Z CMSSM characterised by m 2 0,m 1/2,A 0, tan β, sign µ CMSSM is in agreement with all experimental constraints: Electroweak precision observables (EWPO) + flavour physics + cold dark matter density +... The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.13

14 SUSY-breaking scenarios Hidden sector : Visible sector: SUSY breaking MSSM Gravity-mediated : SUGRA Gauge-mediated : GMSB Anomaly-mediated : AMSB Gaugino-mediated... SUGRA: mediating interactions are gravitational GMSB: mediating interactions are ordinary electroweak and QCD gauge interactions AMSB, Gaugino-mediation: SUSY breaking happens on a different brane in a higher-dimensional theory The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.14

15 Do we live in a meta-stable vacuum? Suppose we live in a SUSY-breaking meta-stable vacuum, while the global minimum has exact SUSY Recent developments: meta-stable vacua arise as generic feature of SUSY QCD with massive flavours Meta-stable SUSY-breaking vacua are generic in local SUSY / string theory, can have cosmologically long life times [K. Intriligator, N. Seiberg, D. Shih 06],... Many new ideas hope for experimental input! The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.15

16 Physics at the LHC and future colliders The Large Hadron Collider (LHC): Proton proton scattering at 7 14 TeV: composite objects of quarks and gluons, bound together by strong interaction p g g p Opens up new energy domain complicated scattering processes 10 9 scattering events/s at LHC design luminosity The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.16

17 HE LHC: Higher Energy LHC Proposal: increase beam energy to 16.5 TeV HE LHC needs new magnets (dipole field: 20 T) new machine Significant increase of LHC search reach, but very good physics justification from future data needed The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.17

18 LHeC: electron proton collisions in the LHC tunnel Ring-Ring (RR) vs. Linac-Ring (LR) option RR: energy limited, < 70 GeV, betterprospectsforhigher luminosity LR: energy not physics limited, considered < 140 GeV; somewhat lower luminosity Baseline configuration: 60 GeV electron energy, luminosity cm 2 s 1 The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.18

19 Potential for new physics searches at LHeC Electron-quark resonances, leptoquarks, SUSY with R-parity violation,... R-parity conserving SUSY: selectron + squark production Higgs production in weak-boson fusion Excited leptons, anomalous top production, CDR in preparation The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.19

20 Linear Colliders: ILC and CLIC The International Linear Collider (ILC): RDR (+ costing) issued in 2007, Technical Design Phase in progress The Compact Linear Collider (CLIC): Ongoing R&D on feasibility issues, preparation of Conceptual Design Report e + e scattering at < 1TeV(ILC), TeV (CLIC) fundamental particles, point-like, electroweak interaction well-defined initial state, full collision energy usable, tunable high-precision physics The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.20

21 Linear Collider Physics Key features: Precisely known centre-of-mass energy of hard process Tunable centre-of-mass energy Polarised beams Clean, fully reconstructable events (also for hadronic final states) Moderate backgrounds no trigger unbiased physics... The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.21

22 High-precision mass determinations from threshold scans Mass measurements at the per-mille level The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.22

23 Determination of chiral structure and test of SUSY relations with polarised beams [G. Moortgat-Pick 05] Test of fundamantal SUSY relations The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.23

24 "Reconstruct the invisible" Model-independent WIMP reconstruction [C. Bartels, J. List 10] Use WIMP production process where a photon is emitted in the initial state: + e γ χ? - e χ Reconstruct WIMP signal from the recoil mass distribution: M 2 recoil = s 2 se γ The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.24

25 Recoil mass distribution: sensitivity to WIMP mass and spin [C. Bartels, J. List 10] [arbitrary units] M χ M χ M χ [GeV]: 120 [GeV]: 160 [GeV]: 200 [arbitrary units] p-wave: J = 1 s-wave: J = 0 dσ/dm Recoil dσ/dm Recoil M Recoil [GeV] M Recoil [GeV] Model-independent information on WIMP properties The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.25

26 Physics at LHC and LC in a nutshell LHC: pp scatt. at 7 14 TeV LC: e + e scattering at < 1TeV (ILC), TeV (CLIC) Scattering process of proton constituents with energy up to several TeV, strongly interacting huge QCD backgrounds, low signal to background ratios Clean exp. environment: well-defined initial state, tunable energy, beam polarization, GigaZ, γγ, eγ, e e options,... rel. small backgrounds high-precision physics The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.26

27 LHC / LC complementarity The results of LHC and LC will be highly complementary LHC: good prospects for producing new heavy states (in particular strongly interacting new particles) LC: direct production (in particular colour-neutral new particles) high sensitivity to effects of new physics via precision measurements LHC / LC interplay enhanced physics gain [LHC / ILC Study Group Report 06] comprehensive picture of TeV scale physics The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.27

28 Muon collider A µ + µ collider in the energy range of 100 GeV to several TeV could emerge as a (major) upgrade of a neutrino factory Higgs production in the s-channel Physics potential of a multi-tev muon collider is in principle similar to a multi-tev e + e collider Can the same luminosity be achieved? [V. Shiltsev 08] Small ISR, beamstrahlung, but huge backgrounds from µ decay The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.28

29 Electroweak symmetry breaking Golden production channel: e + e ZH, Z e + e,µ + µ Higgs discovery possible independently of decay modes (from recoil against Zboson) [P. Garcia-Abia, W. Lohmann 00] σ HZ /σ HZ 2% (E CM =350GeV, Ldt =500fb 1 ) The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.29

30 The ILC will be a Higgs factory Example: E CM =800GeV, 1000 fb 1, M H =120GeV: Higgs events in clean experimental environment Precise measurement of Higgs mass and couplings, determination of Higgs spin and quantum numbers,... Mass determination for a light Higgs: δm exp H 0.05 GeV Verification of Higgs mechanism in model-independent way distinction between different possible manifestations: extended Higgs sector, invisible decays, Higgs radion mixing,... The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.30

31 Example: Higgs coupling determination LHC: no absolute measurement of total production cross section (no recoil method like LEP, ILC: e + e ZH, Z e + e,µ + µ ) Production decay at the LHC yields combinations of Higgs couplings (Γ prod, decay g 2 prod, decay ): σ(h) BR(H a + b) Γ prodγ decay Γ tot, Large uncertainty on dominant decay for light Higgs: H b b LHC can directly determine only ratios of couplings, e.g. g 2 Hττ /g2 HWW The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.31

32 Higgs coupling determination at the LHC Absolute values of the couplings at the LHC can be obtained with an additional (mild) theory assumption: [M. Dührssen, S. Heinemeyer, H. Logan, D. Rainwater, G. W., D. Zeppenfeld 04] g 2 HV V (g2 HV V )SM, V = W, Z Upper bound on Γ V Observation of Higgs production Lower bound on production couplings and Γ tot Observation of H VV in WBF Determines Γ 2 V /Γ tot Upper bound on Γ tot Absolute determination of Γ tot and Higgs couplings The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.32

33 Higgs coupling determination at the ILC Absolute determination of couplings (Z, W, t, b, c, τ) with 1 5% accuracy, no theory assumptions needed Model-independent measurement of the total width Γ γγ :2%measurementatphotoncollideroption The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.33

34 Higgs coupling determination: LHC vs. ILC Comparison: LHC (with mild theory assumptions) vs. ILC (model-independent) [M. Dührssen, S. Heinemeyer, H. Logan, D. Rainwater, G. W., D. Zeppenfeld 04] [K. Desch 06] The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.34

35 Impact of ILC precision for the Higgs couplings SM vs. BSM physics: Precision measurement of Higgs couplings allows distinction between different models The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.35

36 The Higgs as a composite object Renewed interest in composite Higgs models, mostly from extra dimensions [N. Arkani-Hamed, A. Cohen, H. Georgi 01] [K. Agashe, R. Contino, A. Pomarol 05],... Composite Higgs: light remnant of a strong force Relation extra dimensions new strong forces? Correspondence (AdS/CFT): Warped gravity model Technicolour-like theory in 4D Signatures at LHC: new resonances, W, Z, t,kkexcitations Under pressure from electroweak precision tests The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.36

37 Strongly-Interacting Light Higgs: deviation of σ BR from the case of a SM Higgs [G. Giudice, C. Grojean, A. Pomarol, R. Ratazzi 07] Sensitivity at LHC: 20 40%, ILC: 1% ILC can test scales up to 30 TeV The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.37

38 How to make dark matter visible at colliders? SUSY search prospects: Example: Supersymmetry (SUSY) Global χ 2 fit in the CMSSM (m 1/2, m 0, A 0 (GUT scale), tan β, sign(µ) (weak scale)) Fit includes (MasterCode, Markov-chainMonteCarlosampling): [O. Buchmueller, R. Cavanaugh, A. De Roeck, J. Ellis, H. Flächer, S. Heinemeyer, G. Isidori, K. Olive, P. Paradisi, F. Ronga, G. W. 08] Electroweak precision observables: M W, sin 2 θ eff, Γ Z,... + Cold dark matter (CDM) density (WMAP,... ), Ω CDM h 2 = ± (g 2) µ + BPO: BR(b sγ), BR(B s µ + µ ), BR(B τν),... + Kaon decay data: BR(K µν),... The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.38

39 Predictions for the SUSY scale from precision data: CMSSM Comparison: preferred region in the m 0 m 1/2 plane vs. CMS 95% C.L. reach for 0.1, 1fb 1 at 7TeV [O. Buchmueller, R. Cavanaugh, A. De Roeck, J. Ellis, H. Flächer, S. Heinemeyer, G. Isidori, K. Olive, P. Paradisi, F. Ronga, G. W. 10] ] 2 M 1/2 [GeV/c ~ τ LSP 1 tanβ = 10, A 0 = 0, μ > 0 CMS preliminary s=7 TeV Hadronic search, 95% C.L. curves L = 1000/pb L = 100/pb CMS-NOTE full CMSSM parameter space 68% C.L. 95% C.L. NO EWSB M 0 [GeV/c ] Good prospects for early discovery! Get hint in first run? The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.39

40 Spectrum of the best-fit point m [GeV] CMSSM ~ g ~ q ~, t L 2 ~ b 1 ~ q ~, b R ~ t ± H 0 0 A,H ± χ, χ χ h ~ l L,τ 2 ~ l R,τ 1 ν l χ ± χ, χ Good prospects for LHC and ILC The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.40

41 Prospects for dark matter direct detection Present limit and future sensitivities on spin-indep. cross section vs. preferred regions of global fit (CMSSM): [O. Buchmueller, R. Cavanaugh, A. De Roeck, J. Ellis, H. Flächer, S. Heinemeyer, G. Isidori, K. Olive, F. Ronga, G. W. 09] [cm 2 ] SI σ p CDMS: (reanalysis) Ge XENON (Net 136 kg d) SuperCDMS (Projected) 25kg (7 ST@Snolab) m [GeV/c 2 0 χ ] 1 Projected sensitivity of the SuperCDMS (and Xenon 100) direct detection experiments will probe a sizable part of the preferred region in the CMSSM The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p CL

42 χ 2 function for the relic density in the CMSSM without (solid) and with (dashed) the Ω CDM constraint [O. Buchmueller, R. Cavanaugh, A. De Roeck, J. Ellis, H. Flächer, S. Heinemeyer, G. Isidori, K. Olive, F. Ronga, G. W. 09] Δχ Ωh Indirect CDM prediction is in agreement with the measured value of the CDM relic density The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.42

43 Production of SUSY particles at the LHC SUSY production cross sections at the LHC: Prospino2 (T Plehn) 10 3 σ tot [pb]: pp g g, q q, t 1t 1, χ 2 o χ 1+, ν ν, χ 2o g, χ 2o q 10 2 t 1t 1 g g 10 q q χ 2o χ 1+ ν ν χ 2o q χ 2o g S = 14 TeV NLO LO m [GeV] Squark and gluino couplings α s Cross sections mainly determined by m q, g,smallresidual model dependence σ 50 pb for m q, g =500GeV, σ 1pb for m q, g =1TeV The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.43

44 SUSY searches at the LHC Dominated by production of coloured particles: gluino, squarks Very large mass reach in the searches for jets + missing energy gluino, squarks accessible up to 2 3 TeV very good prospects for discovering SUSY particles if low-energy SUSY is realised in nature The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.44

45 SUSY signals at the LHC LHC: good prospects for strongly interacting new particles long decay chains possible complicated final states e.g.: g q q qq χ 0 2 qq ττ qqττ χ 0 1 Many states are produced at once, difficult to disentangle It quacks like SUSY! But is it really SUSY? Which particles are actually produced? Main background for determining SUSY properties at the LHC may be SUSY itself! The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.45

46 It quacks like SUSY, but... does every SM particle really have a superpartner? do their spins differ by 1/2? are their gauge quantum numbers the same? are their couplings identical? do the SUSY predictions for mass relations hold,...? The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.46

47 Even when we are sure that it is actually SUSY, we will still want to know: is the lightest SUSY particle really the neutralino, or the stau or the sneutrino, or the gravitino or...? is it the MSSM, or the NMSSM, or the mnssm, or the N 2 MSSM, or...? what are the experimental values of the 105 (or more) SUSY parameters? does SUSY give the right amount of dark matter? what is the mechanism of SUSY breaking? We will ask similar questions for other kinds of new physics The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.47

48 SUSY searches at the LHC Cascade decays: complicated decay chains for squarks and gluinos q q L χ 0 2 R χ Main tool: dilepton edge from χ 0 2 l + l χ m(ll) (GeV) The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.48

49 Information from kinematical edges and `m2 ll edge = thresholds `m2 χ 0 m 2 lr m 2 `m2 lr 2 χ 0 1 m 2 lr `m2 qll edge = `m2 ql m 2 χ 0 2 `m2 χ 0 m 2 χ `m2 ql edge min = `m2 ql edge max = `m2 ql m 2 χ 0 2 m 2 χ 0 2 `m2 χ 0 2 m 2 χ 0 2 m 2 lr `m2 ql m 2 χ 0 2 `m2 lr m 2 χ 0 1 m 2 lr `m2 qll thres =[(m 2 ql + m 2 χ 0 )(m 2 χ 2 0 m 2 lr )(m 2 lr m 2 χ 2 0 ) 1 r (m 2 q L m 2 χ 0 ) (m 2 χ m 2 lr ) 2 (m 2 lr + m 2 χ 2 0 ) 2 16m 2 χ 1 0 m 4 lr m 2 χ m 2 lr (m 2 q L m 2 χ 0 )(m 2 χ m 2 χ 0 )]/(4m 2 lr m 2 χ 1 0 ) 2 Precise information on mass squared differences From overconstrained system absolute mass determination The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.49

50 Assumption: Constrained MSSM (CMSSM) Improvements from measuring a dilepton edge CMSSM fit with additional information from measuring the opposite-sign dilepton edge in χ 0 2 χ0 1 l+ l (l = e, µ) with 1fb 1 : [O. Buchmueller, R. Cavanaugh, A. De Roeck, J. Ellis, H. Flächer, S. Heinemeyer, G. Isidori, K. Olive, P. Paradisi, F. Ronga, G. W. 08] m 1/2 [GeV] τ LSP 1 CMSSM today s data 68% C.L. 95% C.L. 500 CMSSM 100/pb LHC data % C.L % C.L NO EWSB m 0 [GeV] Big improvement in determination of m 0, m 1/2 The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.50

51 How well can we determine properties of new physics at the LHC? Most studies have been done for favourable benchmark points with light SUSY spectrum, long decay chains with leptons in the final state In order to verify the SUSY nature of new physics we cannot assume an underlying structure like the CMSSM, but we have to test it Need to determine the masses, spins and quantum numbers of as many new particles as possible Determination of SUSY parameters The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.51

52 Particle spins and CP properties Determination of spin and CP prop. of observed new states will be crucial for establishing the SUSY nature of the signal Spin: establish fermion boson symmetry, distinguish from universal extra dimensions (can have similar spectrum as in SUSY, but different spins), spin 2 excitations,... CP properties: pseudo-scalar Higgs, mixed states,... CP violation: Measure CPV effects in CP-conserving observables? Access to CP-violating observables: CP asymmetries, triple products,...? Very important information, but experimentally challenging at the LHC The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.52

53 How precisely do we need to know the SUSY parameters? Dark matter relic density: measurement vs. prediction Ultimate goal: Measure the properties of dark matter candidates at colliders with high precision Obtain predictions in different models that can be compared with cosmological data on the dark matter relic density and the results from direct detection experiments, indirect searches for dark matter,... Comparison will be crucial for testing different dark matter hypotheses and thus for identifying the nature of dark matter AparticularchallengewillbetomatchtheprecisionofWMAP, Planck,... on the dark matter relic density with the corresponding predictions The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.53

54 Prediction of the dark matter density We cannot assume acertainsusyscenario(cmssm),we have to test it Need precision measurements of: LSP mass the dark matter particle LSP couplings NLSP LSP mass difference ( coannihilation region ), down to 0.2 GeV Higgs masses, Higgs couplings ( Higgs funnel region ) Prediction for focus point region depends extremely sensitively on m t through RGE running: would need m t with accuracy of O(20 MeV)... The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.54

55 Production of SUSY particles at the ILC Tunable energy can run directly at threshold Example: Determination of mass and spin of SUSY particle µ R from production at threshold: [TESLA TDR 01] m µ R m µr < test of J =0hypothesis Furthermore: determination of quantum numbers, test of SUSY relations, information on SUSY breaking patterns,... The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.55

56 SUSY thresholds at the LC Example: SPS1a scenario [K. Desch, LHC2FC Workshop 09] The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.56

57 Global fit for MSSM low-energy parameters: Precision observables + LHC + ILC Fit with 18 SUSY parameters, SPS1a [P. Bechtle, K. Desch, M. Uhlenbrock, P. Wienemann 09] Derived Mass Spectrum of SUSY Particles LE+LHC300 MSSM18 Derived Particle Mass [GeV] σ Environment 2σ Environment Best Fit Value 0 h A 0 H 0 H χ 1 χ χ χ χ + χ 2 ~ l R ~ l L τ 1 τ 2 q ~ R q ~ b ~ b ~ ~ t L ~ ~ t 2 g Derived Mass Spectrum of SUSY Particles LE+LHC+ILC MSSM18 Derived Particle Mass [GeV] σ Environment 2σ Environment Best Fit Value 0 h A 0 H 0 H χ 1 χ χ χ χ + χ 2 ~ l R ~ l L τ 1 τ 2 q ~ R q ~ b ~ b ~ ~ t L ~ ~ t 2 g LHC + ILC yield huge improvements compared to LHC The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.57

58 Conclusions LHC will open up the new territory of TeV-scale physics Expect manifestations of mechanism(s) responsible for EWSB and for stabilising hierarchy M Planck / M weak Higgs? SUSY? Extra dimensions?... LHC and LC will provide complementary information in the quest for identifying the nature of new physics Precision data favour a light SUSY scale Good prospects for SUSY searches with early LHC data and for searches for direct detection of dark matter Will LHC and LC be dark matter factories? Need combined input from collider physics, electroweak precision data, cosmological data, direct detection experiments, indirect dark matter searches,... to make dark matter visible The LHC and beyond, Georg Weiglein, Darkness Visible, Cambridge, 08 / 2010 p.58