Slepton and bosino property determination in coanihilation SUSY - PowerPoint PPT Presentation

Studying SUSY in rich models SUSY signatures and backgrounds Background from SM: Real missing energy + pair of SM-particles = di-boson production, with neutrinos: WW → ℓνℓν ZZ → f ¯ f νν Fake missing energy + pair of SM-particles = γγ processes, ISR, single IVB. e + e − → e + e − γγ → e + e − f ¯ f , with both e + e − un-detected. e + e − → f ¯ f γ , with γ un-detected. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 6 / 24

Studying SUSY in rich models SUSY signatures and backgrounds Background from SM: Real missing energy + pair of SM-particles = di-boson production, with neutrinos: WW → ℓνℓν ZZ → f ¯ f νν Fake missing energy + pair of SM-particles = γγ processes, ISR, single IVB. e + e − → e + e − γγ → e + e − f ¯ f , with both e + e − un-detected. e + e − → f ¯ f γ , with γ un-detected. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 6 / 24

Studying SUSY in rich models SUSY signatures and backgrounds Background from SM: Real missing energy + pair of SM-particles = di-boson production, with neutrinos: WW → ℓνℓν ZZ → f ¯ f νν Fake missing energy + pair of SM-particles = γγ processes, ISR, single IVB. e + e − → e + e − γγ → e + e − f ¯ f , with both e + e − un-detected. e + e − → f ¯ f γ , with γ un-detected. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 6 / 24

Studying SUSY in rich models SUSY signatures and backgrounds Background from SM: Real missing energy + pair of SM-particles = di-boson production, with neutrinos: WW → ℓνℓν ZZ → f ¯ f νν Fake missing energy + pair of SM-particles = γγ processes, ISR, single IVB. e + e − → e + e − γγ → e + e − f ¯ f , with both e + e − un-detected. e + e − → f ¯ f γ , with γ un-detected. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 6 / 24

Studying SUSY in rich models Observables: Observable Gives If Edges (or average and ... not too far from width) Masses threshold Shape of spectrum Spin Angular distributions Mass, Spin Invariant mass distributions from full reconstruction Mass ... cascade decays Angular distributions from full reconstruction Spin, CP , ... masses known Un-polarised Cross-section in continuum Mass, coupling Polarised Cross-section Mass, coupling, in continuum mixing Decay product polarisation Mixing ... ˜ τ decays Threshold-scan Mass(es), Spin Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 7 / 24

Studying SUSY in rich models Observables: Observable Gives If Edges (or average and ... not too far from width) Masses threshold Shape of spectrum Spin Angular distributions Mass, Spin Invariant mass distributions Ultimately from full reconstruction Mass ... cascade decays Determine nature of DM Angular distributions from and it’s properties full reconstruction Spin, CP , ... masses known Un-polarised Cross-section in continuum Mass, coupling Polarised Cross-section Mass, coupling, in continuum mixing Decay product polarisation Mixing ... ˜ τ decays Threshold-scan Mass(es), Spin Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 7 / 24

Studying SUSY in rich models Observables: Pair-production, two-body decay Consider e + e − → XX , followed by X → UY , where Y is a detectable (SM) particle. Then � 2 � � � � � � 2 � � 1 + E Y max ( min ) = E Beam M U M X , so that 1 − 1 − ( − ) 2 M X E Beam � M X = E Beam 1 − (∆ / Σ) 2 � 1 − (∆ / Σ) 2 � M U = E Beam 1 − Σ / E Beam ( ∆ = E Y max − E Y min ; Σ = E Y max + E Y min ) If the spectrum is flat (eg if X is a sfermion) between the end-points: � < E Y > = ( E Y max + E Y min ) / 2 and σ E Y = ( E Y max − E Y min ) / 12, which gives � � 2 � 6 σ 2 � 1 − 2 < E Y > EY M U = E Beam 1 − E Beam < E Y > � � 2 � 12 σ 2 EY M X = E Beam 1 − < E Y > Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 8 / 24

Studying SUSY in rich models Observables: Pair-production, two-body decay Consider e + e − → XX , followed by X → UY , where Y is a detectable (SM) particle. Then � 2 � � � � � � 2 � � 1 + E Y max ( min ) = E Beam M U M X , so that 1 − 1 − ( − ) 2 M X E Beam � M X = E Beam 1 − (∆ / Σ) 2 � 1 − (∆ / Σ) 2 � M U = E Beam 1 − Σ / E Beam ( ∆ = E Y max − E Y min ; Σ = E Y max + E Y min ) If the spectrum is flat (eg if X is a sfermion) between the end-points: � < E Y > = ( E Y max + E Y min ) / 2 and σ E Y = ( E Y max − E Y min ) / 12, which gives � � 2 � 6 σ 2 � 1 − 2 < E Y > EY M U = E Beam 1 − E Beam < E Y > � � 2 � 12 σ 2 EY M X = E Beam 1 − < E Y > Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 8 / 24

Studying SUSY in rich models Observables: Pair-production, two-body decay Consider e + e − → XX , followed by X → UY , where Y is a detectable (SM) particle. Then � 2 � � � � � � 2 � � 1 + E Y max ( min ) = E Beam M U M X , so that 1 − 1 − ( − ) 2 M X E Beam � M X = E Beam 1 − (∆ / Σ) 2 � 1 − (∆ / Σ) 2 � M U = E Beam 1 − Σ / E Beam ( ∆ = E Y max − E Y min ; Σ = E Y max + E Y min ) If the spectrum is flat (eg if X is a sfermion) between the end-points: � < E Y > = ( E Y max + E Y min ) / 2 and σ E Y = ( E Y max − E Y min ) / 12, which gives � � 2 � 6 σ 2 � 1 − 2 < E Y > EY M U = E Beam 1 − E Beam < E Y > � � 2 � 12 σ 2 EY M X = E Beam 1 − < E Y > Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 8 / 24

Studying SUSY in rich models Observables: Pair-production, two-body decay Consider e + e − → XX , followed by X → UY , where Y is a detectable (SM) particle. Then � 2 � � � � � � 2 � � 1 + E Y max ( min ) = E Beam M U M X , so that 1 − 1 − ( − ) 2 M X E Beam � M X = E Beam 1 − (∆ / Σ) 2 � 1 − (∆ / Σ) 2 � M U = E Beam 1 − Σ / E Beam ( ∆ = E Y max − E Y min ; Σ = E Y max + E Y min ) If the spectrum is flat (eg if X is a sfermion) between the end-points: � < E Y > = ( E Y max + E Y min ) / 2 and σ E Y = ( E Y max − E Y min ) / 12, which gives � � 2 � 6 σ 2 � 1 − 2 < E Y > EY M U = E Beam 1 − E Beam < E Y > � � 2 � 12 σ 2 EY M X = E Beam 1 − < E Y > Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 8 / 24

A bench-mark point: STC4 Example: STC4 STC4-8 11 parameters. Separate gluino Higgs, un-coloured, and coloured scalar parameters separate Parameters chosen to deliver all constraints (LHC, LEP , cosmology, low energy). At E CMS = 500 GeV: All sleptons available. No squarks. 3 (in e + e − → ˜ χ 0 χ 0 χ 0 Lighter bosinos, up to ˜ 1 ˜ 3 ) (See H. Baer, J. List, arXiv:1307:0782.) Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 9 / 24

A bench-mark point: STC4 Full STC4 mass-spectrum Mass / GeV 2200 g ˜ q L ˜ 2000 q R ˜ 1800 1600 ˜ t 2 ˜ b 2 1400 1200 1000 ˜ 800 b 1 600 χ 0 ˜ H 0 χ ± ˜ 400 H ± 4 χ 0 2 ˜ A 0 3 ˜ ˜ t 1 ℓ L ˜ τ 2 χ 0 χ ± 200 ˜ ˜ ˜ ˜ ν L ν τ 2 1 h 0 χ 0 ˜ ˜ ℓ R ˜ τ 1 1 0 Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 10 / 24

A bench-mark point: STC4 Zoomed STC4 mass-spectrum Mass / GeV 480 χ 0 χ ± ˜ ˜ 4 2 H 0 H ± χ 0 ˜ 400 3 A 0 320 ˜ t 1 240 ˜ ˜ τ 2 ℓ L χ ± χ 0 ˜ ˜ ˜ ˜ 2 1 ν L ν τ 160 ˜ h 0 ℓ R ˜ τ 1 χ 0 ˜ 1 80 0 Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 11 / 24

A bench-mark point: STC4 Channels and observables at 250, 350 and 500 GeV Channel Threshold Available at Can give 212 250 M ˜ τ 1 , ˜ τ 1 nature, τ 1 ˜ ˜ τ 1 τ polarisation 252 250+ + M ˜ µ R , M ˜ 1 , ˜ µ R nature µ R ˜ ˜ µ R χ 0 252 250+ + M ˜ e R , M ˜ 1 , ˜ e R nature e R ˜ ˜ e R χ 0 ∗ ) χ 0 χ 0 χ 0 χ 0 ˜ 1 ˜ 302 350 + M ˜ 2 , M ˜ 1 , nature of ˜ 1 , ˜ χ 0 χ 0 2 2 ∗ ) 325 350 + M ˜ τ 1 ˜ ˜ τ 2 τ 2 θ mix ˜ τ ∗ ) χ 0 ˜ e R ˜ 339 350 + M ˜ e L , ˜ 1 mixing, ˜ e L nature e L 392 500 7 % visible BR ( → ˜ τ 1 W ) ν ˜ ˜ τ ˜ ν ˜ τ ∗ ) χ ± χ ± χ ± 412 500 + M ˜ 1 , nature of ˜ ˜ 1 ˜ χ ± 1 1 ∗ ) e L ˜ ˜ e L 416 500 + M ˜ e L , M ˜ 1 , ˜ e L nature χ 0 ∗ ) µ L ˜ µ L 416 500 + M ˜ µ R , M ˜ 1 , ˜ µ R nature ˜ χ 0 ∗ ) τ 2 ˜ ˜ τ 2 438 500 + M ˜ τ 2 , M ˜ 1 , ˜ τ 2 nature, θ mix ˜ χ 0 τ ∗ ) χ 0 χ 0 χ 0 χ 0 503 500+ + M ˜ 3 , M ˜ 1 , nature of ˜ 1 , ˜ ˜ 1 ˜ χ 0 χ 0 3 3 *): Cascade decays. χ 0 χ 0 + invisible ˜ 1 ˜ 1 , ˜ ν ˜ µ ˜ ν ˜ µ . e , ˜ e , ˜ Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 12 / 24

A bench-mark point: STC4 STC4 @ 500 GeV Features of STC4 @ 500 GeV The ˜ τ 1 is the NLSP . For ˜ τ 1 : E τ, min = 2 . 3 GeV , E τ, max = 45 . 5 GeV : γγ − background ⇔ pairs − background . For ˜ τ 2 : : E τ, min = 52 . 4 GeV , E τ, max = 150 . 0 GeV : WW → l ν l ν − background ⇔ Polarisation . For ˜ e R or ˜ µ R : : E l , min = 7 . 3 GeV , E l , max = 99 . 2 GeV : Neither γγ nor WW → l ν l ν background severe. For pol=(1,-1): σ (˜ e R ˜ e R ) = 1.3 pb ! τ NLSP → τ :s in most SUSY decays → SUSY is background to ˜ SUSY. χ + χ 0 χ 0 For pol=(-1,1): σ (˜ 2 ˜ 2 ) and σ (˜ 1 ˜ χ − 1 ) = several hundred fb and χ 0 χ 0 χ + BR(X → ˜ τ ) > 70 %. For pol=(1,-1): σ (˜ 2 ˜ 2 ) and σ (˜ 1 ˜ χ − 1 ) ≈ 0. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 13 / 24

A bench-mark point: STC4 STC4 @ 500 GeV Features of STC4 @ 500 GeV The ˜ τ 1 is the NLSP . For ˜ τ 1 : E τ, min = 2 . 3 GeV , E τ, max = 45 . 5 GeV : γγ − background ⇔ pairs − background . For ˜ τ 2 : : E τ, min = 52 . 4 GeV , E τ, max = 150 . 0 GeV : WW → l ν l ν − background ⇔ Polarisation . For ˜ e R or ˜ µ R : : E l , min = 7 . 3 GeV , E l , max = 99 . 2 GeV : Neither γγ nor WW → l ν l ν background severe. For pol=(1,-1): σ (˜ e R ˜ e R ) = 1.3 pb ! τ NLSP → τ :s in most SUSY decays → SUSY is background to ˜ SUSY. χ + χ 0 χ 0 For pol=(-1,1): σ (˜ 2 ˜ 2 ) and σ (˜ 1 ˜ χ − 1 ) = several hundred fb and χ 0 χ 0 χ + BR(X → ˜ τ ) > 70 %. For pol=(1,-1): σ (˜ 2 ˜ 2 ) and σ (˜ 1 ˜ χ − 1 ) ≈ 0. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 13 / 24

A bench-mark point: STC4 STC4 @ 500 GeV Features of STC4 @ 500 GeV The ˜ τ 1 is the NLSP . For ˜ τ 1 : E τ, min = 2 . 3 GeV , E τ, max = 45 . 5 GeV : γγ − background ⇔ pairs − background . For ˜ τ 2 : : E τ, min = 52 . 4 GeV , E τ, max = 150 . 0 GeV : WW → l ν l ν − background ⇔ Polarisation . For ˜ e R or ˜ µ R : : E l , min = 7 . 3 GeV , E l , max = 99 . 2 GeV : Neither γγ nor WW → l ν l ν background severe. For pol=(1,-1): σ (˜ e R ˜ e R ) = 1.3 pb ! τ NLSP → τ :s in most SUSY decays → SUSY is background to ˜ SUSY. χ + χ 0 χ 0 For pol=(-1,1): σ (˜ 2 ˜ 2 ) and σ (˜ 1 ˜ χ − 1 ) = several hundred fb and χ 0 χ 0 χ + BR(X → ˜ τ ) > 70 %. For pol=(1,-1): σ (˜ 2 ˜ 2 ) and σ (˜ 1 ˜ χ − 1 ) ≈ 0. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 13 / 24

A bench-mark point: STC4 STC4 @ 500 GeV Features of STC4 @ 500 GeV The ˜ τ 1 is the NLSP . For ˜ τ 1 : E τ, min = 2 . 3 GeV , E τ, max = 45 . 5 GeV : γγ − background ⇔ pairs − background . For ˜ τ 2 : : E τ, min = 52 . 4 GeV , E τ, max = 150 . 0 GeV : WW → l ν l ν − background ⇔ Polarisation . For ˜ e R or ˜ µ R : : E l , min = 7 . 3 GeV , E l , max = 99 . 2 GeV : Neither γγ nor WW → l ν l ν background severe. For pol=(1,-1): σ (˜ e R ˜ e R ) = 1.3 pb ! τ NLSP → τ :s in most SUSY decays → SUSY is background to ˜ SUSY. χ + χ 0 χ 0 For pol=(-1,1): σ (˜ 2 ˜ 2 ) and σ (˜ 1 ˜ χ − 1 ) = several hundred fb and χ 0 χ 0 χ + BR(X → ˜ τ ) > 70 %. For pol=(1,-1): σ (˜ 2 ˜ 2 ) and σ (˜ 1 ˜ χ − 1 ) ≈ 0. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 13 / 24

A bench-mark point: STC4 STC4 @ 500 GeV STC4 @ 500 GeV Strategy: Global preselection to reduce SM, while efficiency for all signals stays above ∼ 90 %. The further select for all sleptons ( ˜ e R , ˜ e L , ˜ µ R , ˜ µ L , ˜ τ 1 ). Next step: specific selections for ˜ e R and ˜ µ R , for ˜ e L and ˜ µ L , and for τ 1 . ˜ Last step: add particle id to separate ˜ e and ˜ µ , special cuts for ˜ τ 1 . Check results both for RL and LR beam-polarisation. In the following, a mix of new results from STC4+SGV@DBD and SPS1a’+FullSim@LOI will be shown Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 14 / 24

A bench-mark point: STC4 STC4 @ 500 GeV STC4 @ 500 GeV Strategy: Global preselection to reduce SM, while efficiency for all signals stays above ∼ 90 %. The further select for all sleptons ( ˜ e R , ˜ e L , ˜ µ R , ˜ µ L , ˜ τ 1 ). Next step: specific selections for ˜ e R and ˜ µ R , for ˜ e L and ˜ µ L , and for τ 1 . ˜ Last step: add particle id to separate ˜ e and ˜ µ , special cuts for ˜ τ 1 . Check results both for RL and LR beam-polarisation. In the following, a mix of new results from STC4+SGV@DBD and SPS1a’+FullSim@LOI will be shown Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 14 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Globaly STC4 global E CMS =500 GeV, Pol=+0.8,-0.3 Jets/2 GeV After a few very general 10 5 cuts: Missing energy > 100 Less than 10 charged tracks 10 4 | cos θ Ptot | < 0 . 95 Exactly two τ -jets Visible mass < 300 GeV 0 25 50 75 100 125 150 175 200 225 250 θ acop between 0.15 and E jet (GeV) 3.1 Magenta: γγ , Blue: 3f, Red: Rest of SM, Green: SUSY. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 15 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: First light - ˜ e R STC4 early discovery: ˜ e R Early discovery channel: crossection in the pb-range. Few simple cuts. Simple observable: E vis : Peak and width gives M ˜ e R and M ˜ 1 . χ 0 See the signal appearing after 1 fb − 1 5 fb − 1 25 fb − 1 100 fb − 1 250 fb − 1 Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 16 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: First light - ˜ e R STC4 early discovery: ˜ e R Early discovery channel: Visible Energy @ 1 fb-1 crossection in the pb-range. 80 Few simple cuts. 70 Simple observable: E vis : Peak 60 and width gives M ˜ e R and M ˜ 1 . χ 0 50 See the signal appearing after 40 1 fb − 1 5 fb − 1 30 25 fb − 1 20 100 fb − 1 250 fb − 1 10 0 0 50 100 150 200 250 300 350 400 Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 16 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: First light - ˜ e R STC4 early discovery: ˜ e R Early discovery channel: Visible Energy @ 5 fb-1 crossection in the pb-range. Few simple cuts. 300 Simple observable: E vis : Peak 250 and width gives M ˜ e R and M ˜ 1 . χ 0 See the signal appearing after 200 1 fb − 1 150 5 fb − 1 25 fb − 1 100 100 fb − 1 50 250 fb − 1 0 0 50 100 150 200 250 300 350 400 Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 16 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: First light - ˜ e R STC4 early discovery: ˜ e R Early discovery channel: Visible Energy @ 25 fb-1 crossection in the pb-range. Few simple cuts. 1400 Simple observable: E vis : Peak 1200 and width gives M ˜ e R and M ˜ 1 . χ 0 1000 See the signal appearing after 800 1 fb − 1 5 fb − 1 600 25 fb − 1 400 100 fb − 1 250 fb − 1 200 0 0 50 100 150 200 250 300 350 400 Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 16 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: First light - ˜ e R STC4 early discovery: ˜ e R Early discovery channel: Visible Energy @ 100 fb-1 crossection in the pb-range. 6000 Few simple cuts. Simple observable: E vis : Peak 5000 and width gives M ˜ e R and M ˜ 1 . χ 0 4000 See the signal appearing after 1 fb − 1 3000 5 fb − 1 2000 25 fb − 1 100 fb − 1 1000 250 fb − 1 0 0 50 100 150 200 250 300 350 400 Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 16 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: First light - ˜ e R STC4 early discovery: ˜ e R Early discovery channel: Visible Energy @ 250 fb-1 crossection in the pb-range. Few simple cuts. 14000 Simple observable: E vis : Peak 12000 and width gives M ˜ e R and M ˜ 1 . χ 0 10000 See the signal appearing after 8000 1 fb − 1 5 fb − 1 6000 25 fb − 1 4000 100 fb − 1 250 fb − 1 2000 0 0 50 100 150 200 250 300 350 400 Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 16 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons STC4 sleptons @ 500 GeV: ˜ e , ˜ µ Selections for ˜ µ and ˜ e : Correct charge. P T wrt. beam and one ℓ wrt the other. Tag and probe, ie. accept one jet if the other is “in the box”. Further selections for R: Cuts on polar angle and angle between leptons. E jet , beam-pol 80%,-30%... ... or beam-pol -80%,30%. Further selections for L (LR): q jet cos θ jet M vis � = M Z Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 17 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons STC4 sleptons @ 500 GeV: ˜ e , ˜ µ Selections for ˜ µ and ˜ e : Correct charge. P T wrt. beam and one ℓ wrt the other. Tag and probe, ie. accept one jet if the other is “in the box”. Further selections for R: Cuts on polar angle and angle between leptons. E jet , beam-pol 80%,-30%... ... or beam-pol -80%,30%. Further selections for L (LR): q jet cos θ jet M vis � = M Z Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 17 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons STC4 sleptons @ 500 GeV: ˜ e , ˜ µ Jets/1 GeV 5000 Selections for ˜ µ and ˜ e : Selectrons R 4000 Correct charge. P T wrt. beam and one ℓ wrt 3000 the other. Tag and probe, ie. accept 2000 one jet if the other is “in the 1000 box”. Further selections for R: 0 0 20 40 60 80 100 120 Jets/1 GeV E jet (GeV) Cuts on polar angle and 5000 Smuons R angle between leptons. 4000 E jet , beam-pol 80%,-30%... 3000 ... or beam-pol -80%,30%. 2000 Further selections for L (LR): q jet cos θ jet 1000 M vis � = M Z 0 0 20 40 60 80 100 120 E jet (GeV) Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 17 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons STC4 sleptons @ 500 GeV: ˜ e , ˜ µ Jets/1 GeV 5000 Selections for ˜ µ and ˜ e : Selectrons R 4000 Correct charge. P T wrt. beam and one ℓ wrt 3000 the other. Tag and probe, ie. accept 2000 one jet if the other is “in the 1000 box”. Further selections for R: 0 0 20 40 60 80 100 120 Jets/1 GeV E jet (GeV) Cuts on polar angle and 5000 Smuons R angle between leptons. 4000 E jet , beam-pol 80%,-30%... 3000 ... or beam-pol -80%,30%. 2000 Further selections for L (LR): q jet cos θ jet 1000 M vis � = M Z 0 0 20 40 60 80 100 120 E jet (GeV) Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 17 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons STC4 sleptons @ 500 GeV: ˜ e , ˜ µ Jets/1 GeV 5000 Selections for ˜ µ and ˜ e : Selectrons L 4000 Correct charge. P T wrt. beam and one ℓ wrt 3000 the other. Tag and probe, ie. accept 2000 one jet if the other is “in the 1000 box”. Further selections for R: 0 0 20 40 60 80 100 120 140 160 Jets/1 GeV E jet (GeV) Cuts on polar angle and 5000 Smuons L angle between leptons. 4000 E jet , beam-pol 80%,-30%... 3000 ... or beam-pol -80%,30%. 2000 Further selections for L (LR): q jet cos θ jet 1000 M vis � = M Z 0 0 20 40 60 80 100 120 140 160 E jet (GeV) Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 17 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons STC4 sleptons @ 500 GeV: ˜ e , ˜ µ 1200 Jets/1 GeV Selections for ˜ µ and ˜ e : 1000 Selectrons L Correct charge. 800 P T wrt. beam and one ℓ wrt 600 the other. Tag and probe, ie. accept 400 one jet if the other is “in the 200 box”. Further selections for R: 0 1200 0 20 40 60 80 100 120 140 160 Jets/1 GeV E jet (GeV) Cuts on polar angle and 1000 Smuons L angle between leptons. 800 E jet , beam-pol 80%,-30%... 600 ... or beam-pol -80%,30%. 400 Further selections for L (LR): q jet cos θ jet 200 M vis � = M Z 0 0 20 40 60 80 100 120 140 160 E jet (GeV) Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 17 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons Masses from ˜ µ in the continuum e , ˜ In R [ E min , E max ] , the MVB exists and is min ( max )( E ℓ ) (!) In presence of background this won’t work. Try to mitigate the effect of extreme cases: Exclude highest/lowest x%, and/or Subdivide in sub-samples and average. Also calculate masses using mean and s.d. of entire spectrum and compare. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 18 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons Masses from ˜ µ in the continuum e , ˜ In R [ E min , E max ] , the MVB exists and is min ( max )( E ℓ ) (!) Jets/1 GeV In presence of background this 5000 Selectrons R won’t work. 4000 Try to mitigate the effect of extreme cases: 3000 Exclude highest/lowest x%, and/or 2000 Subdivide in sub-samples and average. 1000 Also calculate masses using 0 0 20 40 60 80 100 120 mean and s.d. of entire E jet (GeV) spectrum and compare. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 18 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons Masses from ˜ µ in the continuum e , ˜ In R [ E min , E max ] , the MVB exists and is min ( max )( E ℓ ) (!) Jets/1 GeV In presence of background this 5000 Selectrons R won’t work. 4000 Try to mitigate the effect of extreme cases: 3000 Exclude highest/lowest x%, and/or 2000 Subdivide in sub-samples and average. 1000 Also calculate masses using 0 0 20 40 60 80 100 120 mean and s.d. of entire E jet (GeV) spectrum and compare. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 18 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons Masses from ˜ µ in the continuum e , ˜ In R [ E min , E max ] , the MVB LSP exists and is min ( max )( E ℓ ) (!) Rel. freq. 0.35 In presence of background this 0.3 won’t work. From edges From full spect Try to mitigate the effect of 0.25 extreme cases: 0.2 Exclude highest/lowest x%, 0.15 and/or Subdivide in sub-samples 0.1 and average. 0.05 Also calculate masses using 0 100 101 102 103 104 105 106 107 108 109 110 mean and s.d. of entire M seen spectrum and compare. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 18 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons Masses from ˜ µ in the continuum e , ˜ In R [ E min , E max ] , the MVB Slepton exists and is min ( max )( E ℓ ) (!) 0.3 Rel. freq. In presence of background this 0.25 won’t work. From edges From full spect Try to mitigate the effect of 0.2 extreme cases: 0.15 Exclude highest/lowest x%, and/or 0.1 Subdivide in sub-samples and average. 0.05 Also calculate masses using 0 133 134 135 136 137 138 139 140 141 142 143 mean and s.d. of entire M seen spectrum and compare. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 18 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons Masses from ˜ µ in the continuum e , ˜ In R [ E min , E max ] , the MVB Slepton Results from edges (E CMS =500, 500 fb − 1 @ [+0.8,-0.3]) exists and is min ( max )( E ℓ ) (!) 0.3 Rel. freq. In presence of background this e R = 135 . 01 ± 0 . 19 GeV / c 2 M ˜ 0.25 won’t work. From edges 1 = 101 . 51 ± 0 . 14 GeV / c 2 M ˜ χ 0 From full spect Try to mitigate the effect of 0.2 extreme cases: Results for full spectrum (E CMS =500, 500 fb − 1 @ [+0.8,-0.3]) 0.15 Exclude highest/lowest x%, and/or e R = 140 . 90 ± 0 . 33 GeV / c 2 M ˜ 0.1 Subdivide in sub-samples 1 = 107 . 61 ± 0 . 23 GeV / c 2 M ˜ and average. χ 0 0.05 Also calculate masses using 0 133 134 135 136 137 138 139 140 141 142 143 mean and s.d. of entire M seen spectrum and compare. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 18 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons µ R threshold scan ˜ From these spectra, we can estimate M ˜ e R , M ˜ µ R and M ˜ 1 to < χ 0 0.2 GeV. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 19 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons µ R threshold scan ˜ From these spectra, we can estimate M ˜ e R , M ˜ µ R and M ˜ 1 to < χ 0 0.2 GeV. So: Next step is M ˜ µ R from threshold: 10 points, 10 fb − 1 /point. Luminosity ∝ E CMS , so this is ⇔ 170 fb − 1 @ E CMS =500 GeV. Error on M ˜ µ R = 197 MeV ⇒ more studies needed to see if the continuum can match this. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 19 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons µ R threshold scan ˜ ˜ R ) [ fb ] From these spectra, we can 9 data 10 fb -1 / point estimate M ˜ e R , M ˜ µ R and M ˜ 1 to < ˜ R µ χ 0 8 σ (e + e - →µ fit to data : δ M µ ˜ = 197 MeV 0.2 GeV. 7 M µ ˜ = 135.28 GeV 6 So: Next step is M ˜ µ R from ˜ = 135.4 ± 0.2 GeV M µ 5 threshold: 4 10 points, 10 fb − 1 /point. 3 Luminosity ∝ E CMS , so this is 2 ⇔ 170 fb − 1 @ E CMS =500 GeV. 1 0 272 274 276 278 280 282 √ s [ GeV ] Error on M ˜ µ R = 197 MeV ⇒ more studies needed to see if the continuum can match this. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 19 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - sleptons µ R threshold scan ˜ ˜ R ) [ fb ] From these spectra, we can 9 data 10 fb -1 / point estimate M ˜ e R , M ˜ µ R and M ˜ 1 to < ˜ R µ χ 0 8 σ (e + e - →µ fit to data : δ M µ ˜ = 197 MeV 0.2 GeV. 7 M µ ˜ = 135.28 GeV 6 So: Next step is M ˜ µ R from ˜ = 135.4 ± 0.2 GeV M µ 5 threshold: 4 10 points, 10 fb − 1 /point. 3 Luminosity ∝ E CMS , so this is 2 ⇔ 170 fb − 1 @ E CMS =500 GeV. 1 0 272 274 276 278 280 282 √ s [ GeV ] Error on M ˜ µ R = 197 MeV ⇒ more studies needed to see if the continuum can match this. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 19 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM STC4 sleptons @ 500 GeV: ˜ τ 1 Selections for ˜ τ 1 : Correct charge. Jets/1 GeV P T wrt. beam and one τ wrt 600 the other. 500 M jet < M τ E vis < 120 GeV, M vis ∈ [ 20 , 87 ] 400 GeV. 300 Cuts on polar angle and angle between leptons. 200 Little energy below 30 deg, or 100 not in τ -jet. At least one τ -jet should be 0 0 10 20 30 40 50 60 70 hadronic. E jet (GeV) Anti- γγ likelihood. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 20 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM Fitting the ˜ τ mass from end-point (SPS1a’) Results for old analysis of SPS1a’ (See Phys.Rev.D82:055016,2010). Only the upper end-point is relevant. Background subtraction: τ 1 : Important SUSY ˜ background,but region above 45 GeV is signal free. Fit exponential and extrapolate. τ 2 : ∼ no SUSY background ˜ above 45 GeV . Take background from SM-only simulation and fit exponential. Fit line to (data-background fit). Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 21 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM Fitting the ˜ τ mass from end-point (SPS1a’) Results for old analysis of SPS1a’ (See Phys.Rev.D82:055016,2010). Only the upper end-point is relevant. Background subtraction: jets/0.7 Gev 10 3 τ 1 : Important SUSY ˜ background,but region 10 2 above 45 GeV is signal free. Fit exponential and extrapolate. 10 τ 2 : ∼ no SUSY background ˜ above 45 GeV . Take 1 background from SM-only 0 20 40 60 E [GeV] jet simulation and fit exponential. Fit line to (data-background fit). Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 21 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM Fitting the ˜ τ mass from end-point (SPS1a’) Results for old analysis of SPS1a’ (See Phys.Rev.D82:055016,2010). Only the upper end-point is relevant. 800 Background subtraction: jets/1.8 GeV τ 1 : Important SUSY ˜ 600 background,but region above 45 GeV is signal free. 400 Fit exponential and extrapolate. 200 τ 2 : ∼ no SUSY background ˜ above 45 GeV . Take 0 background from SM-only 0 50 100 150 E [GeV] jet simulation and fit exponential. Fit line to (data-background fit). Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 21 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM Fitting the ˜ τ mass from end-point (SPS1a’) Results for old analysis of SPS1a’ (See Phys.Rev.D82:055016,2010). Only the upper end-point is relevant. 800 Background subtraction: jets/1.8 GeV τ 1 : Important SUSY ˜ 600 background,but region above 45 GeV is signal free. 400 Fit exponential and extrapolate. 200 τ 2 : ∼ no SUSY background ˜ above 45 GeV . Take 0 background from SM-only 0 50 100 150 E [GeV] jet simulation and fit exponential. Fit line to (data-background fit). Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 21 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM Fitting the ˜ τ mass from end-point (SPS1a’) Results for old analysis of SPS1a’ (See Phys.Rev.D82:055016,2010). Only the upper end-point is relevant. 800 Background subtraction: jets/1.8 GeV τ 1 : Important SUSY ˜ 600 background,but region Results for ˜ τ 1 above 45 GeV is signal free. − 0 . 05 GeV / c 2 ⊕ 1 . 3 ∆( M ˜ τ 1 = 107 . 73 + 0 . 03 400 M ˜ 1 ) The error from M ˜ 1 largely Fit exponential and χ 0 χ 0 extrapolate. dominates 200 τ 2 : ∼ no SUSY background ˜ above 45 GeV . Take Results for ˜ τ 2 0 background from SM-only 0 50 100 150 E [GeV] − 5 GeV / c 2 ⊕ 18 ∆( M ˜ τ 2 = 183 + 11 jet M ˜ simulation and fit 1 ) The error from the endpoint largely χ 0 exponential. dominates Fit line to (data-background fit). Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 21 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM Fitting the ˜ τ mass from end-point (SPS1a’) Results for old analysis of SPS1a’ (See Phys.Rev.D82:055016,2010). Only the upper end-point is relevant. 800 Background subtraction: jets/1.8 GeV τ 1 : Important SUSY ˜ 600 background,but region Results from cross-section for ˜ τ 1 above 45 GeV is signal free. τ 1 ) = 3 . 2 GeV / c 2 400 ∆( N signal ) / N signal = 3 . 1 % → ∆( M ˜ Fit exponential and extrapolate. 200 τ 2 : ∼ no SUSY background ˜ Results from cross-section for ˜ τ 2 above 45 GeV . Take 0 background from SM-only τ 2 ) = 3 . 6 GeV / c 2 ∆( N signal ) / N signal = 4 . 2 % → ∆( M ˜ 0 50 100 150 E [GeV] jet simulation and fit 1 ) = 1 . 7 GeV / c 2 End-point + Cross-section → ∆( M ˜ χ 0 exponential. Fit line to (data-background fit). Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 21 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM Fitting the ˜ τ mass from end-point (SPS1a’) Results for old analysis of SPS1a’ (See Phys.Rev.D82:055016,2010). Only the upper end-point is relevant. 800 Background subtraction: jets/1.8 GeV τ 1 : Important SUSY ˜ 600 background,but region Also: τ polarisation in ˜ τ 1 decays above 45 GeV is signal free. 400 ∆( P τ ) / P τ = 9 %. Fit exponential and extrapolate. 200 τ 2 : ∼ no SUSY background ˜ above 45 GeV . Take 0 background from SM-only 0 50 100 150 E [GeV] jet simulation and fit exponential. Fit line to (data-background fit). Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 21 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM Fitting masses from cascades (SPS1a’) Nice channel: e + e − → ˜ χ 0 χ 0 2 ˜ 2 , χ 0 ˜ 2 → ˜ µ R µ or → ˜ e R e ) BR= few %. Can be fully kinematically constrained at ILC ⇒ even lower uncertainties on M ˜ µ R and M ˜ e R : ∼ 25 MeV. Also decays to ˜ τ 1 τ can be constrained as good as, or better than a threshold scan. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 22 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM Fitting masses from cascades (SPS1a’) Nice channel: e + e − → ˜ χ 0 χ 0 2 ˜ 2 , χ 0 ˜ 2 → ˜ µ R µ or → ˜ e R e ) 200 BR= few %. 175 Can be fully kinematically 150 constrained at ILC ⇒ 125 even lower uncertainties on 100 M ˜ µ R and M ˜ e R : ∼ 25 MeV. 75 Also decays to ˜ τ 1 τ can be 50 constrained as good as, or 25 better than a threshold scan. 0 100 120 140 160 180 200 M slepton [ GeV/c 2 ] Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 22 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM Fitting masses from cascades (SPS1a’) Nice channel: e + e − → ˜ χ 0 χ 0 2 ˜ 2 , χ 0 ˜ 2 → ˜ µ R µ or → ˜ e R e ) Constant 25.56 Mean 144.7 BR= few %. 30 Sigma 0.8335E-01 Can be fully kinematically 25 constrained at ILC ⇒ 20 even lower uncertainties on M ˜ µ R and M ˜ e R : ∼ 25 MeV. 15 Also decays to ˜ τ 1 τ can be 10 constrained as good as, or 5 better than a threshold scan. 0 144.2 144.3 144.4 144.5 144.6 144.7 144.8 144.9 145 145.1 145.2 M slepton [ GeV/c 2 ] Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 22 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM Fitting masses from cascades (SPS1a’) Nice channel: e + e − → ˜ χ 0 χ 0 2 ˜ 2 , χ 0 ˜ 2 → ˜ µ R µ or → ˜ e R e ) 22.5 f) BR= few %. 20 Can be fully kinematically 17.5 constrained at ILC ⇒ 15 even lower uncertainties on 12.5 M ˜ µ R and M ˜ e R : ∼ 25 MeV. 10 7.5 Also decays to ˜ τ 1 τ can be 5 constrained as good as, or 2.5 better than a threshold scan. 0 100 120 140 160 180 200 M stau [ GeV/c 2 ] Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 22 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM STC4 sleptons @ 500 GeV: ˜ τ 1 and DM In ˜ τ -coannihilation scenarios, Precise determination of the ˜ τ sector ⇒ Predict relic density with sufficient precision ⇒ χ 0 Test whether the ˜ 1 is indeed the dominant DM. Studied by Fittino (similar χ 0 model, with ˜ 1 and ˜ τ 1 identical to STC4). Fit with 18 free parameters, and predict Ω CDM h 2 Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 23 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM STC4 sleptons @ 500 GeV: ˜ τ 1 and DM In ˜ τ -coannihilation scenarios, Precise determination of the ˜ τ sector ⇒ Predict relic density with sufficient precision ⇒ χ 0 Test whether the ˜ 1 is indeed the dominant DM. Studied by Fittino (similar χ 0 model, with ˜ 1 and ˜ τ 1 identical to STC4). Fit with 18 free parameters, and predict Ω CDM h 2 Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 23 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM STC4 sleptons @ 500 GeV: ˜ τ 1 and DM In ˜ τ -coannihilation scenarios, Precise determination of the ˜ τ sector ⇒ Predict relic density with sufficient precision ⇒ χ 0 Test whether the ˜ 1 is indeed the dominant DM. Studied by Fittino (similar χ 0 model, with ˜ 1 and ˜ τ 1 identical to STC4). Fit with 18 free parameters, and predict Ω CDM h 2 Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 23 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM STC4 sleptons @ 500 GeV: ˜ τ 1 and DM In ˜ τ -coannihilation scenarios, Precise determination of the ˜ τ sector ⇒ Predict relic density with sufficient precision ⇒ χ 0 Test whether the ˜ 1 is indeed the dominant DM. Studied by Fittino (similar χ 0 model, with ˜ 1 and ˜ τ 1 identical to STC4). Fit with 18 free parameters, and predict Ω CDM h 2 Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 23 / 24

A bench-mark point: STC4 STC4 @ 500 GeV: Full speed - ˜ τ 1 and DM STC4 sleptons @ 500 GeV: ˜ τ 1 and DM 450 In ˜ τ -coannihilation scenarios, LE+LHC+ILC mSUGRA: � = 0.99995 ± 0.00098 LE+LHC+ILC MSSM18: = 1.00009 0.00208 400 � ± LE+LHC MSSM18: � = 0.97286 ± 0.07131 Precise determination of the ˜ τ 2 WMAP h 1 � ± � 350 DM 2 Planck � h ± 1 � sector ⇒ DM 300 Toy fits 120 Predict relic density with 250 100 sufficient precision ⇒ 80 200 60 χ 0 Test whether the ˜ 1 is indeed 150 40 20 the dominant DM. 100 0 0.992 0.994 0.996 0.998 1 1.002 1.004 1.006 1.008 50 Studied by Fittino (similar χ 0 0 model, with ˜ 1 and ˜ τ 1 identical 0 0.2 0.4 0.6 0.8 1 1.2 2 2 to STC4). h (predicted)/ h (measured) � � DM DM Fit with 18 free parameters, and predict Ω CDM h 2 Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 23 / 24

Outlook & Conclusions Outlook & Conclusions If STCx is realised, We could have extremely precise information on DM: Is it SUSY ? Is it only SUSY? In any case: would open up, not only precission SUSY at ILC (“ILC is the LEP of SUSY”), but also new branch of cosmology... To get extremely precise information: Specific reconstruction methods for e , µ , τ and bosinos (comming). Make a coherent study of all channels, at all E CMS stages. Also channels not studied in SPS1a’ Exploit more complex decay cascades. Revisit the many-parameter fit w/ fittino. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 24 / 24

Outlook & Conclusions Outlook & Conclusions If STCx is realised, We could have extremely precise information on DM: Is it SUSY ? Is it only SUSY? In any case: would open up, not only precission SUSY at ILC (“ILC is the LEP of SUSY”), but also new branch of cosmology... To get extremely precise information: Specific reconstruction methods for e , µ , τ and bosinos (comming). Make a coherent study of all channels, at all E CMS stages. Also channels not studied in SPS1a’ Exploit more complex decay cascades. Revisit the many-parameter fit w/ fittino. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 24 / 24

Outlook & Conclusions Outlook & Conclusions If STCx is realised, We could have extremely precise information on DM: Is it SUSY ? Is it only SUSY? In any case: would open up, not only precission SUSY at ILC (“ILC is the LEP of SUSY”), but also new branch of cosmology... To get extremely precise information: Specific reconstruction methods for e , µ , τ and bosinos (comming). Make a coherent study of all channels, at all E CMS stages. Also channels not studied in SPS1a’ Exploit more complex decay cascades. Revisit the many-parameter fit w/ fittino. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 24 / 24

Outlook & Conclusions Outlook & Conclusions If STCx is realised, We could have extremely precise information on DM: Is it SUSY ? Is it only SUSY? In any case: would open up, not only precission SUSY at ILC (“ILC is the LEP of SUSY”), but also new branch of cosmology... To get extremely precise information: Specific reconstruction methods for e , µ , τ and bosinos (comming). Make a coherent study of all channels, at all E CMS stages. Also channels not studied in SPS1a’ Exploit more complex decay cascades. Revisit the many-parameter fit w/ fittino. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 24 / 24

Outlook & Conclusions Outlook & Conclusions If STCx is realised, We could have extremely precise information on DM: Is it SUSY ? Is it only SUSY? In any case: would open up, not only precission SUSY at ILC (“ILC is the LEP of SUSY”), but also new branch of cosmology... To get extremely precise information: Specific reconstruction methods for e , µ , τ and bosinos (comming). Make a coherent study of all channels, at all E CMS stages. Also channels not studied in SPS1a’ Exploit more complex decay cascades. Revisit the many-parameter fit w/ fittino. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 24 / 24

Outlook & Conclusions Outlook & Conclusions If STCx is realised, We could have extremely precise information on DM: Is it SUSY ? Is it only SUSY? In any case: would open up, not only precission SUSY at ILC (“ILC is the LEP of SUSY”), but also new branch of cosmology... To get extremely precise information: Specific reconstruction methods for e , µ , τ and bosinos (comming). Make a coherent study of all channels, at all E CMS stages. Also channels not studied in SPS1a’ Exploit more complex decay cascades. Revisit the many-parameter fit w/ fittino. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 24 / 24

Outlook & Conclusions Outlook & Conclusions If STCx is realised, We could have extremely precise information on DM: Is it SUSY ? Is it only SUSY? In any case: would open up, not only precission SUSY at ILC (“ILC is the LEP of SUSY”), but also new branch of cosmology... To get extremely precise information: Specific reconstruction methods for e , µ , τ and bosinos (comming). Make a coherent study of all channels, at all E CMS stages. Also channels not studied in SPS1a’ Exploit more complex decay cascades. Revisit the many-parameter fit w/ fittino. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 24 / 24

Outlook & Conclusions Outlook & Conclusions If STCx is realised, We could have extremely precise information on DM: Is it SUSY ? Is it only SUSY? In any case: would open up, not only precission SUSY at ILC (“ILC is the LEP of SUSY”), but also new branch of cosmology... To get extremely precise information: Specific reconstruction methods for e , µ , τ and bosinos (comming). Make a coherent study of all channels, at all E CMS stages. Also channels not studied in SPS1a’ Exploit more complex decay cascades. Revisit the many-parameter fit w/ fittino. Mikael Berggren (DESY) SUSY property determination LCWS, Oct 2014 24 / 24

Outlook & Conclusions Thank You !

Backup BACKUP BACKUP SLIDES

Backup Observables: Pair-production, two-body decay (less text) So, there are two SUSY parameters, and two independent observables in the spectrum. Any pair of observables can be chosen, edges, average, standard deviation, width, ... Which choice is the best depends on the situation. Just a bit of algebra to extract the two SUSY masses. Note that if E beam >> M X , there is just one observable (low edge becomes 0, width becomes average/2), so one should not operate too far above threshold ! Note that there are two decays in each event: two measurements per event. Also note that there are not enough measurements to make a constrained fit, even assuming that the two SUSY particles in the two decays are the same: (2 × 4 unknown components of 4-momentum (=8)) - ( total E and p conservation (=4) + 2 equal-mass constraints) = 2 remaining unknowns.

Backup Observables: Pair-production, two-body decay (less text) So, there are two SUSY parameters, and two independent observables in the spectrum. Any pair of observables can be chosen, edges, average, standard deviation, width, ... Which choice is the best depends on the situation. Just a bit of algebra to extract the two SUSY masses. Note that if E beam >> M X , there is just one observable (low edge becomes 0, width becomes average/2), so one should not operate too far above threshold ! Note that there are two decays in each event: two measurements per event. Also note that there are not enough measurements to make a constrained fit, even assuming that the two SUSY particles in the two decays are the same: (2 × 4 unknown components of 4-momentum (=8)) - ( total E and p conservation (=4) + 2 equal-mass constraints) = 2 remaining unknowns.

Backup Observables: Pair-production, two-body decay (less text) So, there are two SUSY parameters, and two independent observables in the spectrum. Any pair of observables can be chosen, edges, average, standard deviation, width, ... Which choice is the best depends on the situation. Just a bit of algebra to extract the two SUSY masses. Note that if E beam >> M X , there is just one observable (low edge becomes 0, width becomes average/2), so one should not operate too far above threshold ! Note that there are two decays in each event: two measurements per event. Also note that there are not enough measurements to make a constrained fit, even assuming that the two SUSY particles in the two decays are the same: (2 × 4 unknown components of 4-momentum (=8)) - ( total E and p conservation (=4) + 2 equal-mass constraints) = 2 remaining unknowns.

Backup Observables: Pair-production, two-body decay (less text) So, there are two SUSY parameters, and two independent observables in the spectrum. Any pair of observables can be chosen, edges, average, standard deviation, width, ... Which choice is the best depends on the situation. Just a bit of algebra to extract the two SUSY masses. Note that if E beam >> M X , there is just one observable (low edge becomes 0, width becomes average/2), so one should not operate too far above threshold ! Note that there are two decays in each event: two measurements per event. Also note that there are not enough measurements to make a constrained fit, even assuming that the two SUSY particles in the two decays are the same: (2 × 4 unknown components of 4-momentum (=8)) - ( total E and p conservation (=4) + 2 equal-mass constraints) = 2 remaining unknowns.

Backup Observables: Pair-production, two-body decay However: If the masses are known from other measurements, there are enough constraints. Then the events can be completely reconstructed ... ... and the angular distributions both in production and decay can be measured. From this the spins can be determined, which is essential to determine that what we are seeing is SUSY. Furthermore: Looking at more complicated decays, such as cascade decays, there are enough constraints if some (but not all) masses are known. 2 → ˜ χ 0 χ 0 Allows to reconstruct eg. the slepton mass in ˜ ℓℓ → ℓℓ ˜ 1 if chargino and LSP masses are known. Order-of-magnitude better mass resolution.

Backup Observables: Pair-production, two-body decay However: If the masses are known from other measurements, there are enough constraints. Then the events can be completely reconstructed ... ... and the angular distributions both in production and decay can be measured. From this the spins can be determined, which is essential to determine that what we are seeing is SUSY. Furthermore: Looking at more complicated decays, such as cascade decays, there are enough constraints if some (but not all) masses are known. 2 → ˜ χ 0 χ 0 Allows to reconstruct eg. the slepton mass in ˜ ℓℓ → ℓℓ ˜ 1 if chargino and LSP masses are known. Order-of-magnitude better mass resolution.

Backup Observables: Pair-production, two-body decay However: If the masses are known from other measurements, there are enough constraints. Then the events can be completely reconstructed ... d) 200 ... and the angular distributions both in production and decay can 175 be measured. 150 From this the spins can be determined, which is essential to 125 determine that what we are seeing is SUSY. 100 Furthermore: 75 Looking at more complicated decays, such as cascade decays, 50 there are enough constraints if some (but not all) masses are known. 25 2 → ˜ χ 0 χ 0 0 Allows to reconstruct eg. the slepton mass in ˜ ℓℓ → ℓℓ ˜ 1 if 100 120 140 160 180 200 M slepton [ GeV/c 2 ] chargino and LSP masses are known. Order-of-magnitude better mass resolution.

Backup Observables But this is not all ! The cross-section in e + e − → XX close to threshold depends both on coupling, spin and kinematics (= β ). The distribution of the angle between the two SM-particles depends on β , in a complicated, but calculable way. The cross-section is different for L and R SUSY particles. So checking how much the cross-section changes when switching beam-polarisations measures mixing. Measure the helicity of the SM particle → properties of the particles in the decay, ie. in addition to the produced X, also the χ 0 χ 0 invisible U. In one case this is possible: In ˜ τ → τ ˜ 1 → X ν τ ˜ 1 .

Backup Observables But this is not all ! The cross-section in e + e − → XX close to threshold depends both on coupling, spin and kinematics (= β ). The distribution of the angle between the two SM-particles depends on β , in a complicated, but calculable way. The cross-section is different for L and R SUSY particles. So checking how much the cross-section changes when switching beam-polarisations measures mixing. Measure the helicity of the SM particle → properties of the particles in the decay, ie. in addition to the produced X, also the χ 0 χ 0 invisible U. In one case this is possible: In ˜ τ → τ ˜ 1 → X ν τ ˜ 1 .

Backup Observables But this is not all ! The cross-section in e + e − → XX close to threshold depends both on coupling, spin and kinematics (= β ). The distribution of the angle between the two SM-particles depends on β , in a complicated, but calculable way. The cross-section is different for L and R SUSY particles. So checking how much the cross-section changes when switching beam-polarisations measures mixing. Measure the helicity of the SM particle → properties of the particles in the decay, ie. in addition to the produced X, also the χ 0 χ 0 invisible U. In one case this is possible: In ˜ τ → τ ˜ 1 → X ν τ ˜ 1 .

Backup Observables But this is not all ! The cross-section in e + e − → XX close to threshold depends both on coupling, spin and kinematics (= β ). The distribution of the angle between the two SM-particles depends on β , in a complicated, but calculable way. The cross-section is different for L and R SUSY particles. So checking how much the cross-section changes when switching beam-polarisations measures mixing. Measure the helicity of the SM particle → properties of the particles in the decay, ie. in addition to the produced X, also the χ 0 χ 0 invisible U. In one case this is possible: In ˜ τ → τ ˜ 1 → X ν τ ˜ 1 .

Backup τ channels ˜ Extracting the ˜ τ properties See Phys.Rev.D82:055016,2010 Use polarisation (0.8,-0.22) to reduce bosino background. From decay kinematics: M ˜ τ from M ˜ 1 and end-point of spectrum = E τ, max . χ 0 Other end-point hidden in γγ background:Must get M ˜ 1 from other χ 0 sources. ( ˜ µ , ˜ e , ...) From cross-section: τ , P beam ) × β 3 / s , so σ ˜ τ = A ( θ ˜ � 1 − ( σ s / A ) 2 / 3 : no M ˜ M ˜ τ = E beam 1 ! χ 0 From decay spectra: P τ from exclusive decay-mode(s): handle on mixing angles θ ˜ τ and θ ˜ χ 0 1

Backup τ channels ˜ Topology selection Take over SPS1a’ ˜ τ analysis principle ˜ Select this by: ℓ properties: Exactly two jets. Only two particles (possibly τ :s:s) in the final state. N ch < 10 Large missing energy and Vanishing total charge. momentum. Charge of each jet = ± 1, High Acolinearity, with little M jet < 2.5 GeV / c 2 , correlation to the energy of the E vis significantly less than τ decay-products. E CMS . Central production. M miss significantly less than No forward-backward M CMS . asymmetry. No particle with momentum + anti γγ cuts. close to E beam .

Backup τ channels ˜ Topology selection Take over SPS1a’ ˜ τ analysis principle ˜ Select this by: ℓ properties: Exactly two jets. Only two particles (possibly τ :s:s) in the final state. N ch < 10 Large missing energy and Vanishing total charge. momentum. Charge of each jet = ± 1, High Acolinearity, with little M jet < 2.5 GeV / c 2 , correlation to the energy of the E vis significantly less than τ decay-products. E CMS . Central production. M miss significantly less than No forward-backward M CMS . asymmetry. No particle with momentum + anti γγ cuts. close to E beam .

Backup τ channels ˜ Topology selection Take over SPS1a’ ˜ τ analysis principle ˜ Select this by: ℓ properties: Exactly two jets. Only two particles (possibly τ :s:s) in the final state. N ch < 10 Large missing energy and Vanishing total charge. momentum. Charge of each jet = ± 1, High Acolinearity, with little M jet < 2.5 GeV / c 2 , correlation to the energy of the E vis significantly less than τ decay-products. E CMS . Central production. M miss significantly less than No forward-backward M CMS . asymmetry. No particle with momentum + anti γγ cuts. close to E beam .

Backup τ channels ˜ τ 1 and ˜ τ 2 further selections ˜ ˜ τ 1 : ( E jet 1 + E jet 2 ) sin θ acop < 30 GeV . [GeV] ˜ τ 2 : b) 30 Other side jet not e or µ to 1st jet Most energetic jet not e or µ Cut on Signal-SM LR of 20 pt f ( q jet 1 cos θ jet 1 , q jet 2 cos θ jet 2 ) Efficiency 15 (22) % 10 0 0 10 20 30 pt [GeV] to 2nd jet