Determination of SUSY Parameters at LHC/ILC Hans-Ulrich Martyn RWTH Aachen & DESY

H-U MartynSUSY parameter determination at LHC/ILC 2 Outline Why and how to explore supersymmetry Discovery and measurements at LHC Precision measurements at ILC Reconstructing supersymmetry Dark matter and colliders Scenarios off mainstream Summary and outlook

H-U MartynSUSY parameter determination at LHC/ILC 3 Why supersymmetry Most attractive extension of Standard Model ensures naturalness of hierarchy scales unification of fundamental gauge forces provides cold dark matter candidate stabilisation of light Higgs mass corrections local SUSY incorporates gravity additional sources of CP violation maximal symmetry of fermions & bosons EW data consistent with weak-scale SUSY LHC experiments outcome extremely important, huge impact on future projects - ILC, VLHC, superB, super… discovery - revolution in particle physics Ellis et al 06

H-U MartynSUSY parameter determination at LHC/ILC 4 MSSM Building blocks SM  MSSM – duplication of particles  sparticles – 105 new parameters in MSSM R-parity conserving Biggest mystery - symmetry breaking invoke hidden sector Plethora of mediation mechanisms: gravity, gauge, gaugino, anomaly, string inspired, …  reduced set of parameters – what are dominant effects producing couplings of hidden sector and MSSM fields: tree-level, loop-induced,..., ? Hidden sectorMSSM sector Flavour blind mediators

H-U MartynSUSY parameter determination at LHC/ILC 5 Soft parameters GUT scale  low scale MSSM  Observables mSUGRA: m 0, m 1/2, A, tanβ, sign  string inspired models GMSB AMSB ….. masses, decay widths, spin, couplings, mixings, quantum numbers, cross-sections R P V, CPV, LFV … neutralinos/charginos sleptons squarks Higgs (h,H,A) , tanβ, A f at present RGE M GUT, M X, M S, HO corrections, renormalisation scheme..., ?

H-U MartynSUSY parameter determination at LHC/ILC 6 Soft parameters GUT scale  low scale MSSM  Observables mSUGRA: m 0, m 1/2, A, tanβ, sign  string inspired models GMSB AMSB ….. masses, decay widths, spin, couplings, mixings, quantum numbers, cross-sections R P V, CPV, LFV … neutralinos/charginos sleptons squarks Higgs (h,H,A) , tanβ, A f in future all obstacles solvable with sufficient precision data -- need new techniques at hadron colliders

H-U MartynSUSY parameter determination at LHC/ILC 7 Experimental facilities LHC TeV 2008 start 14 TeV goal: few fb -1 per experiment 2010 reliable results on new physics, discoveries? huge discovery potential up to scales of m ~ 2.5 TeV ILC 2006 reference design 2009 technical design … ready for decision years construction polarised e + e -, e - e -, γγ high-precision measurements up to kinematic limit TeV pp 14 TeVe + e - 1 TeV

H-U MartynSUSY parameter determination at LHC/ILC 8 Exploring supersymmetry LHC Dominant production of strongly interacting squarks, gluinos Many states produced at once, long decay chains  complicated final states ILC Production of non-colored sleptons, neutralinos, charginos Select exclusive reactions, bottom-up approach, model independent analysis Considerable synergy between LHC and ILC combined analyses, concurrent running SPS 1a’ mSUGRA benchmark favourable for LHC & ILC

H-U MartynSUSY parameter determination at LHC/ILC 9 Discovering SUSY at LHC Signatures from gluino/squark decay chain: high p T multi-jets, isolated leptons, large missing energy Inclusive search M eff = ∑ 1,4 E T i + E T miss QCD background reliably calculable? W, Z, tt production  Anastasiou

H-U MartynSUSY parameter determination at LHC/ILC 10 Early discovery of SUSY at LHC? Is there New Physics? What is the scale? Science community expects fast and reliable answers, e.g. planning for future facilities Understanding detector and E T misss spectrum crucial! Discovery potential vs luminosity

H-U MartynSUSY parameter determination at LHC/ILC 11 Reconstructing masses at LHC Exploit variety of invariant mass distributions, low & high end points Construct kinematic constraints on sparticle masses  precise mass differences  seriously limited by poor neutralino mass Nojiri, SUSY06 strong sl R - χ 1 correlation

H-U MartynSUSY parameter determination at LHC/ILC 12 Reconstructing masses at LHC End point method: waste of statistics and information Mass relation method: exact kinematics using complete events bbll channel – 5 masses: each event define 4-dim hypersurface in 5-dim mass space – 5 events sufficient to solve mass equations – many events: overconstraint fit, solve for masses, improved resolution All sparticle masses known:  reconstruction LSP momentum Kawagoe, Nojiri, Polesello 2004

H-U MartynSUSY parameter determination at LHC/ILC 13 Spin, L/R sfermion? Shape of decay distribution carry spin information Problems: pick up correct combination quark + near lepton, tell ql + from anti-ql + Solution: lepton charge asymmetry Assumptions: more squarks than antisquarks squarks/sleptons dominantly left or right neutralino spin ½ Distinct from other models, e.g. UED spinless

H-U MartynSUSY parameter determination at LHC/ILC 14 Finding sparticles with help of ILC Light neutralinos and chargino found at ILC  Prediction of masses of heavy neutralinos and chargino may not be accessible at ILC New particle can be identified at LHC via ‘edge’ in the di-lepton mass spectrum LHC/ILC interplay: Phys.Rept.426 (2006) 47

H-U MartynSUSY parameter determination at LHC/ILC 15 SPS 1a’ spectrum from LHC LHC analysis access to high mass states, sleptons and gauginos via cascades resolution limited by strong correlations with neutralino LSP mass differences much more accurate Correct interpretation?       neutralino sneutrino KK photon Aguilar-Saavedra et al 2006

H-U MartynSUSY parameter determination at LHC/ILC 16 Masses at ILC Energy spectrum, end points δm ~ 0.1 GeV Threshold excitation curve c haracteristic β dependence, steep rise δm ~ GeV flat energy spectrum

H-U MartynSUSY parameter determination at LHC/ILC 17 Masses -stau Stau production flat energy spectrum distorted to triangular shape fit upper end point  m stau Coannihilation region small Δm = m stau -m χ  3 GeV accessible difficult measurement due to huge γγ bkg important to get DM constraint very problematic for LHC m stau = 173 GeV δm ~ 0.3 GeV Point D’ m stau = 218 GeV Δm = 5 GeV δm ~ 0.15 GeV h-um 04 E+E+ E-E-

H-U MartynSUSY parameter determination at LHC/ILC 18 Masses - gauginos Neutralino production Chargino production Many reactions to get the mass of the lightest neutralino very accurately! δm ~ 0.05 GeV

H-U MartynSUSY parameter determination at LHC/ILC 19 Masses - cascade decays Decay chains à la LHC kinematics of cascade decay provides access to intermediate slepton 2-fold ambiguity for mass solutions  extremely narrow mass peak δm/m ~ 5∙10 -5 Similarly: selectron reconstruction Berggren 05

H-U MartynSUSY parameter determination at LHC/ILC 20 Masses & mixings Chargino sector Mass matrix masses from threshold excitation Mixings polarised cross sections σ L,R [11] and σ L,R [12] disentangle ambiguities and determine mixing angles cos 2Φ LR Choi et al 2000

H-U MartynSUSY parameter determination at LHC/ILC 21 Masses & mixings Stop production lightest squark in many scenarios, difficult to detect at LHC Mixing polarised cross sections Minimal mass reconstructed from kinematics, momentum correlations, using m χ  peak at m stop Finch et al 04 SPS 5 Bartl et al 97

H-U MartynSUSY parameter determination at LHC/ILC 22 Spin Threshold production and Angular distribution all masses known: reconstruction polar angle Θ (2-fold ambiguity) Unambiguous spin assignment model inependent, distinct from e.g. UED L/R quantum numbers via polarisation R sfermions prefer right-handed electrons e - R L sfermions prefer left-handed electrons e - L Choi et al 2006

H-U MartynSUSY parameter determination at LHC/ILC 23 Couplings Basic element of SUSY identical gauge and Yukawa couplings SU(2) gauge g = Yukawa ĝ U(1) gauge g’ = Yukawa ĝ’ Slepton production Freitas et al, 04

H-U MartynSUSY parameter determination at LHC/ILC 24 SPS 1a’ spectrum from LHC+ILC Coherent LHC+ILC analysis complementary spectrum completed superior to sum of individual analyses accuracy increased by 1-2 orders of magnitude Challenge: experimental accuracy matched by theory?       Aguilar-Saavedra et al 2006

H-U MartynSUSY parameter determination at LHC/ILC 25 How to proceed? We want to understand the relation between the visible sector, observables, and the fundamental theory  SUSY provides a predictive framework How precise can we predict masses, x-sections, branching ratios, couplings, … ? – many relations between sparticle masses at tree-level, much worse at loop-level – choice of renormalisation scheme? Which precision can be achieved on parameters of the MSSM Lagrangian? – Lagrangian parameters not directly measurable – parameters not always directly related to a particular observable, e.g. µ, tan ß – fitting procedure, … Can we reconsruct the fundamental theory at high scale? – unification of couplings, soft masses, … ? – which SUSY breaking mechanism, origin of SUSY breaking? Goals of the SPA Project

H-U MartynSUSY parameter determination at LHC/ILC 26 SPA convention and project Supersymmetry Parameter Analysis Supported by ~100 theorists & experimentalists SPA Convention renormalisation schemes / LE parameters / observables Program repository theor. & expt. analyses / LHC+ILC tools / Susy Les Houches Accord scheme translation, RGE & spectrum calculators, event generators, fitting, … Theoretical and experimental tasks short- and long-term sub-projects, SUSY calc. vs expt., LO  NLO  NNLO, …, new channels & observables, combine LHC+ILC data Reference point SPS 1a’ derivative of SPS 1a, consistent with all LE and cosmological data Future developments CP-MSSM, NMSSM, R p V, effective string theory, etc. You are invited to join!  EPJC 46 (2006) 43http://spa.desy.de/spa/  Hollik, Robens

H-U MartynSUSY parameter determination at LHC/ILC 27 Extracting Lagrange parameters Global fit of all available ‘data’ to most up-to-date HO calculations input: masses, edges, x-sects, BRs from LHC & ILC ~120 values incl. realistic error correlations theory: no errors (no reliable estimate available) output: ~20 parameters tools Fittino (Bechtle, Desch, Wienemann), SFitter (Lafaye, Plehn, D. Zerwas) Results SPS 1a’ high precision LHC alone not able to constrain most parameters  Arkani-Hamed

H-U MartynSUSY parameter determination at LHC/ILC 28 High-scale extrapolation Gauge couplings α -1 grand unification ~2σ / g i U ~2% ε 3 at ~8σ level

H-U MartynSUSY parameter determination at LHC/ILC 29 High-scale extrapolation Universality of gaugino & scalar mass parameters in mSUGRA Evolution in GMSB distinctly different from mSUGRA Bottom-up evolution of Lagrange parameters provides high sensitivity to SUSY breaking schemes Q [GeV] 1/M i [GeV -1 ]M j 2 [10 3 GeV 2 ] mSUGRA Q [GeV] M j 2 [10 3 GeV 2 ] GMSB M  Porod

H-U MartynSUSY parameter determination at LHC/ILC 30 Testing mSUGRA mSUGRA fit excellent Universality can be tested in bottom-up approach non-coloured sector at permil to percent level colored sector needs improvement LHC+ILC: Telescope to Planck scale physics

H-U MartynSUSY parameter determination at LHC/ILC 31 metastable stau Dark matter & colliders Cold dark matter in Universe Ω DM ≈ 22% Ω DM h 2 = ± WMAP Understanding nature of cold dark matter requires direct detection DM particle in astrophysical expt precise measurement of DM particle mass & spin at colliders compare relic density calculation with observation Ω χ h 2 ~ 3 ∙ cm 3 s -1 / requires typical weak interaction annihilation cross section Candidates: neutralino, gravitino, sneutrino, axino, … Formation: freeze out of thermal equilibrium in general Ω χ » 0.2, annihilation mechanism needed thermal production late decays  Kraml, Allanach

H-U MartynSUSY parameter determination at LHC/ILC 32 Neutralino dark matter SPS 1a’ ‘bulk region’ annihilation through slepton exchange χχ  тт, bb σ χχ depends on light slepton masses & couplings LHC: precision ~20% ( very high lumi) assuming mSUGRA, ‘a posteriori’ estimate/fix of unconstrained parameters, e.g. mixings LHC + ILC: precision ~1-2% matches WMAP/Planck expts  Reliable prediction for direct neutralino - proton detection cross section Baltz 06

H-U MartynSUSY parameter determination at LHC/ILC 33 Neutralino dark matter LCC2 ‘focus point region’ heavy sfermions, light gauginos annihilation ΧΧ  WW, ZZ σ χχ depends on M 1, M 2, μ, tanβ LHC: study gluino decays, not enough constraints to solve neutralino matrix LHC + ILC: ~10% precision on relic abundance ILC resolves LHC multiple solutions bino wino Higgsino M1M1 μ parasitic LHC peak at Ωχ ~ 0

H-U MartynSUSY parameter determination at LHC/ILC 34 Gravitino dark matter Gravitino mass set by SUSY breaking scale F of mediating interaction m 3/2 =F/√3∙M P Planck scale M P =2.4∙10 18 GeV In general free parameter depending on scenario supergravity, gaugino, gauge mediation m 3/2 = TeV … eV Most interesting: gravitino LSP, stau NLSP m 3/2 = few GeV - few 100 GeV Dominant decay gravitational coupling, lifetime sec - years Gravitino not detectable in astrophysical expts

H-U MartynSUSY parameter determination at LHC/ILC 35 Gravitino dark matter Detecting metastable staus & gravitinos identify & record stopping stau  stau mass wait until decay  stau lifetime measure τ recoil spectra  gravitino mass rare radiative decays  gravitino spin γ- τ correlations in LHC detectors not appropriate stau mass ok, no lifetime or decay spectra moderate rate, high background, busy timing external absorber/calorimeter needed ILC ideal environment high rate, adjustable via cms energy low duty cycle ~0.5%, excellent calorimetry Hamaguchi et al 04, Feng, Smith 04, DeRoeck et al 05, H-UM 06

H-U MartynSUSY parameter determination at LHC/ILC 36 trap Gravitino dark matter GDM ε scenario m o =m 3/2 =20 GeV, M 1/2 =440 GeV ILC case study L=100 fb 500 GeV (<1 year data taking) Prolific stau production Lifetime measurement Decay spectrum  Access to Planck scale / Newton’s constant SUSY breaking scale Unique test of supergravity: gravitino = superpartner of graviton H-U M, EPJC 48 (2006) 15

H-U MartynSUSY parameter determination at LHC/ILC 37 Off mainstream scenarios Scenario SPS 1a’ is just a benchmark, a test bed Nature may be very different from SPS 1a’, mSUGRA, or … Other possibilities – complex parameters, CP phases baryogenesis – lepton flavour violation neutrino masses – R-parity violation unstable LSP, neutrino masses – alternative SUSY breaking mediation anomaly, gauge, gaugino, … mixed scenarios of SUSY breaking – additional matter/gauge fields NMSSM, UMSSM, ESSM, … – additional dimensions – split SUSY – and many more … Different signatures at LHC / ILC

H-U MartynSUSY parameter determination at LHC/ILC 38 CP phases CPV in SUSY may explain baryon asymmetry CP phases affect CP-even quantities generate CP-odd observables (triple products) EDM constraints for 1 st, 2 nd generation sfermions and charginos/neutralinos mSUGRA Φ μ < Stop decay widths μ, A t strong phase dependence Φ(A t ) of stop  chargino + b Neutralino sector in selectron production μ, M 1 pure Χ i 0 exchange in t and u channel transversely polarised e - e - beams cross section CP even azimuthal asymmetry CP odd p se_L ∙(s e1 x s e2 ) complementary to SPS 1a S/√L Bartl et al  Kernreiter, Rolbiecki 2 L=100 fb -1 m=380 GeV

H-U MartynSUSY parameter determination at LHC/ILC 39 Lepton Flavour Violation LFV in slepton pair production Seesaw mechanism to generate neutrino masses m ν LR extension: ν R singlet fields and superpartners added to MSSM sensitivity σ LFV ~ fb  Majorana mass scale M R ~ GeV  radiative decay Br(μ  eγ)~ Massive neutrinos affect RGEs of sleptons flavour off-diagonal terms with large Yukawa couplings for 3 rd generation kink in evolution of L 3, H 2 M(ν R3 ) = (5.9±1.6) GeV μe τμ SPS 1a Deppisch et al 04 Blair et al 05  Deppisch SPS 1a’

H-U MartynSUSY parameter determination at LHC/ILC 40 Split SUSY SUSY breaking scale split between scalar & gaugino sectors Spectrum light Higgs, neutralinos, charginos, gluino squarks, sleptons, H, A extremely heavy Signatures strongly dependent on gluino lifetime long-lived gluino, R-hadrons LHC displaced vertices stable R 0  missing E T stable R +  balanced p T Chargino/neutralino sector LHC & ILC conventional phenomenology for searches/masses anomalous Yukawa couplings from gaugino-Higgsino mixing Both LHC & ILC needed to establish SUSY Lagrangian at common scalar mass scale m˜ Arkani-Hamed, Dimopoulos Kilian et al 04  Provenza

H-U MartynSUSY parameter determination at LHC/ILC 41 Summary & outlook Experiments at LHC will tell if weak-scale supersymmetry is realised in nature Methods and techniques have been developed to discover and explore supersymmetry. Close contacts between experiment and theory are needed to go beyond basic discovery  SPA project provides a platform for discussions Both accelerators, the LHC and a future ILC, are necessary to understand the sparticle spectrum in detail and to unravel in a model-independent way the fundamental supersymmetry theory High-precision measurements of low-energy Lagrange parameters offer the unique possibility to perform reliable extrapolations towards the GUT / Planck scale and to test the concepts of unification of the laws of physics