Higgs and SUSY at an e+e- Linear Collider

Towards Physics at the Linear Collider Naturalness gives an indication on the scale of New Physics, once mH is known; Expect Higgs discovery at Tevatron or LHC EW data from LEP/SLC/Tevatron indicate that mH is light, or there is New Physics of certain specific types [Peskin, Wells, 2001]: if mH < 180 GeV rich program of precision mapping of Higgs profile at ILC; if NP, ILC/CLIC best suited for detailed mapping through EW data + direct searches. mH < 182 GeV

Studying NP at Colliders beyond LHC ILC to provide point-like particle collisions from 0.3 TeV up to ~ 1 TeV with tunable centre-of-mass energies, particle species and polarization states; In a farther future, CLIC multi-TeV e+e- collider may further push energy frontier up to 3 – 5 TeV.

ILC Energy Accelerating Gradient vs. RF Frequency: [ILC 0.5 – 1.0 TeV] [CLIC 1.0-5.0 TeV] CLIC ILC

Progress with S.C. Cavity Gradient

Towards Detailed Analyses Essential to validate anticipated results with analyses based on full G4 simulation and reconstruction; LC physics program presents significant challenges to detector design and machine-detector interface to preserve the signature e+e- clean event reconstruction; Parallel effort in providing reconstruction tools with required precision;

Benchmarks for the ILC Develop list of benchmark processes where i) ILC physics scenarios broadly covered, ii) benchmarks robust and retain wider scope, iii) detector performance manifest in direct way, iv) target performance motivated by quantitatively well-defined requirements.

Benchmarks for the ILC

ILC Physics Signatures ILC Physics program has possibly the broadest range of particle kinematics and event topologies; Within a single physics scenario, DM-motivated Supersymmetry, below are some of the signal signatures which need to be measured with O(0.1 - 1%) accuracy:

Higgs Sector Profile at ILC T Barklow, hep-ph/0411221

H0gbb, cc, gg at 0.35 - 0.5 TeV Determination of Higgs hadronic branching fractions, one of the most crucial tests of the Higgs mechanism of mass generation and unique to the ILC for the experimental accuracy needed to match theory uncertainties and probe extended Higgs sector models;

H0gbb, cc, gg at 0.35 - 0.5 TeV Determination of Higgs hadronic branching fractions, one of the most crucial tests of the Higgs mechanism of mass generation and unique to the ILC; Light Higgs boson offers opportunity and challenge: couplings to b, c and t quark accessible, but need to tag b, c, light jets with 70 : 3 : 7 ratio in signal. 120GeV dBR(HgX)/BR Hgbb Hgcc Hggg Kuhl, Desch LC-PHSM-2007-001

H0gbb, cc, gg at 0.35 - 0.5 TeV Hgbb Hgcc Hggg + 0% +15% + 5% spoint: Channel Change Rel. Change in Stat. Uncertainty Hgbb Hgcc Hggg Geometry: 5 g 4 layer VTX Thickness: 50 mm g 100 mm + 0% +15% + 5% spoint: 4 mm g 6 mm 4 mm g 2 mm +10% -10% Yu et al. J. Korean Phys. Soc. 50 (2007); Kuhl, Desch LC-PHSM-2007-001; Ciborowski,Luzniak Snowmass 2005 Degradation in performance correspond to 20-30% equivalent Luminosity loss.

H g t+t- and m+m- dgHtt/gHtt dgHmm/gHmm Determination of gHmm coupling important to test Higgs mechanism in lepton sector, high energy e+e- collisions offer a unique opportunity; Sensitivity being assessed for 0.35 – 0.5 TeV in Higgstrahlung process, Process accessible in WW fusion at higher energy, precision measurement in multi-TeV collisions: Ecm TeV MH 120 140 150 dgHtt/gHtt 0.5 0.027 0.050 dgHmm/gHmm 0.8 0.150 3.0 0.042 0.065 0.12 MB, 2002

e+e- g neneHgm+m- at 3 TeV s(e+e-gHnn) = 0.51 pb for MH=118.8 GeV, Ecm = 3 TeV BR(Hgmm) = 0.026 % SM Background s(e+e-gmmnn) = 4.7 fb Mokka+Marlin SiD Model 3 TeV Preliminary Analysis performed using SiD model in MOKKA 06-01 and Marlin 00.09.06; Results for 3 ab-1 Signal 179 29 dgHmm/gHmm 0.042 MB, 2007

e+e-g nnH0gbb at 1 TeV Large WW fusion cross section at large Ecm gives access to gHbb over full range compatible with LEP-2 +EW data: For mH = 200 GeV, Hgbb becomes rare decay (2 x 10-3), still ILC at 1 TeV can get its branching fraction to 9% accuracy: T Barklow

Determining the Higgs Potential Fundamental test of Higgs potential shape through independent Determination of gHHH in double Higgs production Opportunity unique to the ILC, LHC cannot access double H production and SLHC may have only marginal accuracy; several LC analyses pioneered by P. Gay et al.

HH Mass Decay Angle Double Higgstrahlung at 0.5-0.8 TeV Double WW Fusion at 1-3 TeV HH Mass Decay Angle MB, Boos, Yao, 2005

Barklow, LCWS07

e+e- gH0H0Z0 at 0.5 TeV with LDC Isolating HHZ signal (s=0.18fb) from tt (s=530fb), ZZZ (s=1.1fb), tbtb (s=0.7fb) and ttZ (s=0.7fb) is an experimental tour-de-force; b-tagging and jet energy resolution essential to suppress backgrounds; Boumediene, Gay, LCWS07

e+e- gH0H0Z0 at 0.5 TeV with LDC Understand impact of detector performance on triple Higgs couplings determination accuracy at ILC Parametric Simulation L = 2 ab-1 Boumediene, Gay, LCWS07

e+e- gH0H0Z0 at 0.5 TeV with SiD Re-analysis of HHZ production with realistic, yet parametric simulation of SiD detector and full SM backgronds; Emphasis of Particle Flow performance and algorithm optimisation; Barklow, LCWS07

The Higgs Profile and the Physics beyond In models with extended Higgs sector, such as SUSY, Higgs couplings get shifted w.r.t. SM predictions: Desch et al., hep-ph/0406322

The Effect of Theory Uncertainties Droll, Logan, PRD76 (2007)

Invisible Higgs Decays In ADD model mixing of Higgs and KK graviscalar and H decay in graviscalar pairs generate invisible width which can be detected at ILC; Study of invisible H decay and at ILC allows to tightly constrain model parameters: LHC ILC MB, Dominici, Gunion, Wells, LCWS05

Invisible Higgs Decays Radion mixing in RS models shifts Higgs couplings; Possible reduction of Higgs yields at LHC but clear signature in ILC data from precision data on bb and WW couplings: MB, De Curtis, Dominici et al., PLB568 (2003)

DM-motivated SUSY at ILC If DM due to WIMPs manifesting New Physics beyond SM, next generation of hadron (LHC, SLHC) and lepton collider (ILC, CLIC) expected to discover direct signal of this NP and perform detailed studies; Collider data will combine with direct searches and satellite experiments to understand DM properties from microscopic to macroscopic scales; Supersymmetry offers attractive framework to study opportunities at colliders experiments;

Model Independent WIMP Detection at ILC Irreducible SM bkg removed by using polarised beams Analysis performed with full G4 simulation and reconstruction; C Bartels, J List

Model Independent WIMP Detection at ILC Alternatively, use photon spectrum directly and scan Mc – annihilation fraction; Assume beam polarisation, realistic ECal resolution; Konar, Matchev, Perelstein et al

Solving the SUSY Inverse Problem Resolve the degeneracies arising by reconstructing fundamental parameters from LHC experimental observables; Arkani-Hamed, Kane, Thaler, Wang, hep-ph/0512190 242 models with 164 degenerate pairs at LHC 82 models, 72 pairs visible at 0.5 TeV ILC; 55 pairs distinguishable at ILC; 75% of accessible model pairs degenerate at LHC can be solved at LC, but large Ecm essential Study LHC-degenerate models at 0.5 TeV and 1 TeV ILC, J Hewett, T Rizzo, Gainer et al.

Cosmologically interesting cMSSM Regions and Benchmark points Systematic study of ILC reach promoted by US study group on ILC-Cosmo Connections Cosmologically interesting cMSSM Regions and Benchmark points Compute RGEs with Isajet 7.69 and estimate dark matter density from Isajet spectrum and couplings with MicrOMEGAS 1.3 and DarkSUSY 4.0 J Ellis, K Olive, MB, M Peskin,…

Constraining the Higgs Sector with WCDM Allanach et al.,hep-ph/0507283

SUSY Bulk Region Heavy part of SUSY spectrum decouples from Wc determination LCC1 Benchmark

A Comparison of DM density accuracy at LHC and ILC in Bulk Region WMAP Baltz,MB,Peskin,Wizanski, PRD74 (2006) but bulk region not quite representative of SUSY phase space...

in Baryogenesis motivated Scenarios Stop co-Annihilation in Baryogenesis motivated Scenarios Light scalar top, nearly degenerate with neutralino, provides efficient co-annihilation and evades Tevatron searches due to small ET. LHC ILC Baryogenesis constraints push towards heavy scalar and introduces CP-violating phase in m. Scenario shares several features characteristic of FP region but requires analysis of real Z0 and light stops. Carena, Freytas, hep-ph/0608255

Heavy Higgses at LHC/SLHC and DM F Gianotti

Heavy Higgs Sector in MSSM DM (GeV) DG (GeV) 0.24 1.5 Desch et al., hep-ph/0406229

Heavy MSSM Higgses , Wch2 and LCC4

The Higgs Sector of the LCC4 Point LCC4 point in A0 Funnel region Benchmark point defined in cMSSM LCC4 Benchmark

Selection Criteria General selection cuts: at least 4 hadronic jets (JADE algorithm) (at least 5 ptc/jet); force event to 4 jets; apply di-jet btagging; reconstruction Efficiency = 40 % Ncha > 20 Ntot > 100 Echa > 250 GeV Etot > 850 GeV ET > 350 GeV y34 < 0.0025 Thrust < 0.96 Mjj > 150 GeV

Selection Criteria Etot

4-jet Kinematic Fit Perform constrained kinematic fit to 4-jet system, which uses Lagrange multipliers and minimises a c2 constructed from the measured energies and directions of the jets; Impose centre-of-mass energy and momentum conservation; Consider jj jj pairing giving smallest mass difference and plot di-jet masses Mjj (2 entries / evt); Port of PUFITC+ developed for DELPHI at LEP2 (N Kjaer, M Mulders) to MarlinReco framework MB, Hooberman

to Parametric Simulation Compare Full G4+Reco to Parametric Simulation SIMDET G4+Marlin SIMDET Fast Simulation Full G4+ MarlinReco Preliminary MB, LCWS04 MB, Hooberman, LCWS07

Further DM Constraints from HA BR(A gbb) Analysis of Markov Chain MSSM scans to identify further observables to possibly improve DM density determination at the ILC

t t A0 Branching Fraction Determination b b b b b b Contrast bbtt to bbbb based on missing energy, nb. of hadronic jets and jj+recoil masses; bbtt Reconstruction Efficiency 35% b b b Determine BR(Agtt) from rate of bbtt to bbbb tags, WW + ZZ background appears small; b Expect ~ 0.15 ~0.07 t t b

Stau Tri-linear Coupling - Atau Constrain Atau through H g tt decays: Stau Couplings to H/A: ~~ Atau A H In A funnel, MA<Mt1+Mt2 and the only such decay allowed by CP for the pseudoscalar Agt1t2 is not available; Heavy H0 gt1t1 scales with Atau and can be used to constrain stau trilinear coupling in this regime.

Stau Tri-linear Coupling - Atau H/A Branching Ratios vs Atau Atau scan for LCC4 MSSM parameters with HDECAY 2.0 Large Hgt1t1 can be detected by standard bbtt + bbbb analysis and used to constrain Stau trilinear coupling

for LCC4 with HA analysis DM density accuracy for LCC4 with HA analysis Phys.Rev.D74:103521,2006. MB, Hooberman, Kelley

Collider Experiments on Dark Matter Dark Matter Density g0.08 Baltz, MB, Peskin, Wiszanski, PRD74 (2006)

within MSSM on cMSSM plane dW/W ILC Accuracy within MSSM on cMSSM plane 0.08 0.18 J Ellis, K Olive, MB et al.