TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jetsTeV–Scale Supersymmetry at the LHC

Tilman Plehn

University of Edinburgh

KEK, 12/2007

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Outline

TeV–scale new physics

TeV–scale supersymmetry

Masses from cascades

Underlying parameters

Spin from cascades

Spins from jets

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Standard–Model effective theory

Remember the Standard Model?

– gauge theory with local SU(3) × SU(2) × U(1)

– massless SU(3) and U(1) gauge bosonsmassive W ,Z bosons [Higgs mechanism with v = 246 GeV]

– Dirac fermions in doublets with masses = Yukawasgeneration mixing in quark and neutrino sector

– renormalizable Lagrangian [no 1/masses]

– only missing piece: Higgs [fundamental? minimal? mass unknown]

⇒ defined by particle content, interactions, renormalizability

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Standard–Model effective theory

Remember the Standard Model?

– gauge theory with local SU(3) × SU(2) × U(1)

– massless SU(3) and U(1) gauge bosonsmassive W ,Z bosons [Higgs mechanism with v = 246 GeV]

– Dirac fermions in doublets with masses = Yukawasgeneration mixing in quark and neutrino sector

– renormalizable Lagrangian [no 1/masses]

– only missing piece: Higgs [fundamental? minimal? mass unknown]

⇒ defined by particle content, interactions, renormalizability

How complete experimentally?

– dark matter? [solid evidence! — for weak–scale new physics?]

– quark mixing — flavor physics? [new operators above 104 GeV?]

– neutrino masses and mixing? [see-saw at 1011 GeV?]

– matter–antimatter asymmetry? [universe mostly matter]

– gravity missing? [mostly negligible but definitely non-renormalizable]

⇒ cut-off scale unavoidable, size negotiable [SM an effective theory]

⇒ all philosophy — who the hell cares???

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

TeV–scale new physicsH

t

H

WTheorists care — when looking at data which...

...indicates a light Higgs [e-w precision data]

...indicates higher–scale physics [at least dark matter is BSM]

– problem of light Higgs: mass driven to cutoff of effective Standard Model:δm2

H ∝ g2(2m2W + m2

Z + m2H − 4m2

t ) Λ2

– easy solution: counter term to cancel loops ⇒ artificial, unmotivated, ugly

– or new physics at TeV scale: supersymmetry [my favorite]

extra dimensionslittle Higgscomposite Higgs, TopColorYourFavoriteNewPhysics...

⇒ beautiful concepts, but problematic in reality [data seriously in the way]

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

TeV–scale new physicsH

t

H

WTheorists care — when looking at data which...

...indicates a light Higgs [e-w precision data]

...indicates higher–scale physics [at least dark matter is BSM]

– problem of light Higgs: mass driven to cutoff of effective Standard Model:δm2

H ∝ g2(2m2W + m2

Z + m2H − 4m2

t ) Λ2

– easy solution: counter term to cancel loops ⇒ artificial, unmotivated, ugly

– or new physics at TeV scale: supersymmetry [my favorite]

extra dimensionslittle Higgscomposite Higgs, TopColorYourFavoriteNewPhysics...

⇒ beautiful concepts, but problematic in reality [data seriously in the way]

– discrete symmetry good for e-w precision constraints, proton decay

– stable lightest new particle: dark matter [correct relic density]

⇒ TeV–scale models in baroque state

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

TeV–scale new physicsH

t

H

WTheorists care — when looking at data which...

...indicates a light Higgs [e-w precision data]

...indicates higher–scale physics [at least dark matter is BSM]

– problem of light Higgs: mass driven to cutoff of effective Standard Model:δm2

H ∝ g2(2m2W + m2

Z + m2H − 4m2

t ) Λ2

– easy solution: counter term to cancel loops ⇒ artificial, unmotivated, ugly

– or new physics at TeV scale: supersymmetry [my favorite]

extra dimensionslittle Higgscomposite Higgs, TopColorYourFavoriteNewPhysics...

⇒ beautiful concepts, but problematic in reality [data seriously in the way]

– discrete symmetry good for e-w precision constraints, proton decay

– stable lightest new particle: dark matter [correct relic density]

⇒ TeV–scale models in baroque state

Alternative motivations for TeV–scale new physics

– alternatives to (fundamental) Higgs mechanism?

– gauge coupling unification almost perfect?

– Uli Baur’s rule: new energy scales bring new physics!

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

TeV–scale supersymmetryH

t

H

WSupersymmetry

– give each Standard–Model particle a partner [with different spin, including strong interactions]

– SUSY obviously broken by masses [soft breaking, mechanism unknown]

– sooo not an LHC paradigm: maximally blind mediation [MSUGRA, CMSSM]

scalars — m0 fermions — m1/2 tri-scalar — A0 Higgs sector — sign(µ), tan β

– assume dark matter, stable lightest partner

⇒ measure BSM spectrum with missing energy at LHC

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

TeV–scale supersymmetryH

t

H

WSupersymmetry

– give each Standard–Model particle a partner [with different spin, including strong interactions]

– SUSY obviously broken by masses [soft breaking, mechanism unknown]

– sooo not an LHC paradigm: maximally blind mediation [MSUGRA, CMSSM]

scalars — m0 fermions — m1/2 tri-scalar — A0 Higgs sector — sign(µ), tan β

– assume dark matter, stable lightest partner

⇒ measure BSM spectrum with missing energy at LHC

LHC searches: MSSM

– conjugate Higgs field not allowed→ give mass to t and b?→ five Higgs bosons

– SUSY–Higgs alone interesting...

...but not conclusive

...and another talk

⇒ list of SUSY partners

spin d.o.f.fermion fL, fR 1/2 1+1→ sfermion fL, fR 0 1+1gluon Gµ 1 n-2→ gluino g 1/2 2 Majoranagauge bosons γ, Z 1 2+3Higgs bosons ho , Ho, Ao 0 3→ neutralinos χo

i 1/2 4 · 2 LSP

gauge bosons W± 1 2 · 3Higgs bosons H± 0 2→ charginos χ

±i 1/2 2 · 4

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Masses from cascades

Cascade decays [Atlas-TDR, Cambridge]

)2 (GeV/cg~

M0 100 200 300 400 500 600

)2 (G

eV/c

q~M

0

100

200

300

400

500

600observed 95% C.L.obs. ISR/FSR syst. incl.expected 95% C.L.

no mSUGRAsolution

)10

χ∼) < m(q~m(LEP 1 + 2

UA

1

UA

2

FNAL Run I

g~

= Mq~M

CDF Run II Preliminary -1L=1.1 fb

3-jets inclusive<0µ=5, β=0, tan0A

)2 (GeV/cg~

M0 100 200 300 400 500 600

)2 (G

eV/c

q~M

0

100

200

300

400

500

600

– if new particles strongly interactingand LSP weakly interacting

– like Tevatron: jets + missing energy

– tough: (σBR)1/(σBR)2 [unavoidable: focus point]

– easier: cascade kinematics [107 · · · 108 events]

– long chain g → bb → χ02bb→ µ+µ−bbχ0

1

– thresholds & edges0 < m2

µµ <

m2χ0

2− m2

˜

m ˜

m2˜− m2

χ01

m ˜

⇒ new–physics mass spectrum from cascade kinematics

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Masses from cascades

Cascade decays [Atlas-TDR, Cambridge]

10-3

10-2

10-1

1

10

100 150 200 250 300 350 400 450 500

⇑⇑

⇑

⇑⇑ ⇑⇑

χ2oχ1

+

t1t−1

qq−

gg

νν−

χ1+q

χ1og

NLOLO

√S = 2 TeV

m [GeV]

σtot[pb]: pp− → gg, qq

−, t1t

−1, χ2

oχ1+, νν

−, χ1

og, χ1+q

– if new particles strongly interactingand LSP weakly interacting

– like Tevatron: jets + missing energy

– tough: (σBR)1/(σBR)2 [unavoidable: focus point]

– easier: cascade kinematics [107 · · · 108 events]

– long chain g → bb → χ02bb→ µ+µ−bbχ0

1

– thresholds & edges0 < m2

µµ <

m2χ0

2− m2

˜

m ˜

m2˜− m2

χ01

m ˜

⇒ new–physics mass spectrum from cascade kinematics

0

1

2

0 2500

0.2

0.4

0 2500

0.250.5

0.751

0 2500

0.2

0.4

0.6

0 250

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Masses from cascades

Cascade decays [Atlas-TDR, Cambridge]

10-2

10-1

1

10

10 2

10 3

100 150 200 250 300 350 400 450 500

⇑

⇑ ⇑ ⇑

⇑

⇑⇑

χ2oχ1

+

t1t−1

qq−

gg

νν−

χ2og

χ2oq

NLOLO

√S = 14 TeV

m [GeV]

σtot[pb]: pp → gg, qq−, t1t

−1, χ2

oχ1+, νν

−, χ2

og, χ2oq

– if new particles strongly interactingand LSP weakly interacting

– like Tevatron: jets + missing energy

– tough: (σBR)1/(σBR)2 [unavoidable: focus point]

– easier: cascade kinematics [107 · · · 108 events]

– long chain g → bb → χ02bb→ µ+µ−bbχ0

1

– thresholds & edges0 < m2

µµ <

m2χ0

2− m2

˜

m ˜

m2˜− m2

χ01

m ˜

⇒ new–physics mass spectrum from cascade kinematics

0

1

2

0 2500

0.2

0.4

0 2500

0.250.5

0.751

0 2500

0.2

0.4

0.6

0 250

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Masses from cascades

Cascade decays [Atlas-TDR, Cambridge]

10-2

10-1

1

10

10 2

10 3

100 150 200 250 300 350 400 450 500

⇑

⇑ ⇑ ⇑

⇑

⇑⇑

χ2oχ1

+

t1t−1

qq−

gg

νν−

χ2og

χ2oq

NLOLO

√S = 14 TeV

m [GeV]

σtot[pb]: pp → gg, qq−, t1t

−1, χ2

oχ1+, νν

−, χ2

og, χ2oq

– if new particles strongly interactingand LSP weakly interacting

– like Tevatron: jets + missing energy

– tough: (σBR)1/(σBR)2 [unavoidable: focus point]

– easier: cascade kinematics [107 · · · 108 events]

– long chain g → bb → χ02bb→ µ+µ−bbχ0

1

– thresholds & edges0 < m2

µµ <

m2χ0

2− m2

˜

m ˜

m2˜− m2

χ01

m ˜

⇒ new–physics mass spectrum from cascade kinematics

Alternative methods [Nojiri, Polessello]

– do not only use events at end points

– reconstruct masses from external momenta

– add events with identical topology until systems solves

⇒ LHC better than inclusive rates

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Masses from cascades

Cascade decays [Atlas-TDR, Cambridge]

g

b~ χ2

oµ~

χ1o

bb µ

µ

– if new particles strongly interactingand LSP weakly interacting

– like Tevatron: jets + missing energy

– tough: (σBR)1/(σBR)2 [unavoidable: focus point]

– easier: cascade kinematics [107 · · · 108 events]

– long chain g → bb → χ02bb→ µ+µ−bbχ0

1

– thresholds & edges0 < m2

µµ <

m2χ0

2− m2

˜

m ˜

m2˜− m2

χ01

m ˜

⇒ new–physics mass spectrum from cascade kinematics

Gluino decay [Gjelsten, Miller, Osland]

– all decay jets b quarks [otherwise dead by QCD]

– no problem: off-shell effects

– no problem: jet radiation

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Masses from cascades

Cascade decays [Atlas-TDR, Cambridge]

– if new particles strongly interactingand LSP weakly interacting

– like Tevatron: jets + missing energy

– tough: (σBR)1/(σBR)2 [unavoidable: focus point]

– easier: cascade kinematics [107 · · · 108 events]

– long chain g → bb → χ02bb→ µ+µ−bbχ0

1

– thresholds & edges0 < m2

µµ <

m2χ0

2− m2

˜

m ˜

m2˜− m2

χ01

m ˜

⇒ new–physics mass spectrum from cascade kinematics

Gluino decay [Gjelsten, Miller, Osland]

– all decay jets b quarks [otherwise dead by QCD]

– no problem: off-shell effects

– no problem: jet radiation

– gluino mass to ∼ 1%

⇒ but why physical masses?

Sparticle masses and mass differences [GeV]0 100 200 300 400 500 600

10χ∼

mRl

~ m20χ∼

m

1b~m

Lq~m

g~m

10χ∼

- mg~m

10χ∼

- mLq

~m

10χ∼

- m1b

~m

10 χ∼- m

20 χ∼m

10 χ∼- m

R l~m

1b~ -

mg~

m

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

New physics and jets

Squarks and gluinos always with many jets [Rainwater, TP, Skands]

– cascade studies sensitive to jet activity? [compare to Pythia shower]

– matrix element gg+2j and uLg+2j [pT ,j > 100 GeV]

– hard scale µF huge for SUSY

– obvious: pT ,j spectra fine with jet radiation

– miracle: angular correlations better than 10%

⇒ QCD not a problem in new–physics signals [Jay’s next paper]

σ [pb] t t600 gg uL gσ0j 1.30 4.83 5.65σ1j 0.73 2.89 2.74σ2j 0.26 1.09 0.85

10-2

10-1

1

0 100 200 300 400

10-2

10-1

1

0 100 200 300 400

pT,j (pp→ttj)

dσ/d

p T [p

b/G

eV]

pT,j≥50 GeV|ηj|<5, ∆Rjj>0.4KPythia=1.8

LHC:Susy-MadGraphPythia: pT

2 (power) pT

2 (wimpy) Q2 (power) Q2 (wimpy) Q2 (tune A)

pT,jmax (pp→ttjj)

pT,j≥50 GeV

pT,jmin (pp→ttjj)

GeV

pT,j≥50 GeV

10-2

10-1

1

0 100 200 300 400

10-5

10-4

10-3

0 100 200 300 400

10-5

10-4

10-3

0 100 200 300 400

pT,j (pp→uLuLj)

dσ/d

p T [p

b/G

eV]

pT,j≥50 GeV|ηj|<5, ∆Rjj>0.4KPythia=1.25

LHC: sps1amodSusy-MadGraphPythia: pT

2 (power) pT

2 (wimpy) Q2 (power) Q2 (wimpy) Q2 (tune A)

pT,jmax (pp→uLuLjj)

pT,j≥100 GeV

pT,jmin (pp→uLuLjj)

GeV

pT,j≥100 GeV

10-5

10-4

10-3

0 100 200 300 400

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Underlying parameters

From kinematics to weak–scale parameters [Fittino; SFitter: Lafaye, TP, Rauch, Zerwas]

– back to question: parameters by weak-scale Lagrangian

– measurements: masses or edges,branching fractions, rates,... [Prospino]

flavor, dark matter, electroweak constraints,...

– errors: general correlation, statistics & systematics & theory [flat theory errors!]

– problem in grid: huge phase space, no local maximum?problem in fit: domain walls, no global maximum?problem in interpretation: bad observables, secondary maxima?

Probability maps of new physics [Baltz,...; Roszkowski,...; Allanach,...; SFitter]

– fully exclusive likelihood map p(d |m) over m [hard part]

– LHC problem: remove pathetic directions [e.g. endpoints or dark matter vs rates]

– Bayesian: p(m|d) ∼ p(d |m) p(m) with theorists’ bias p(m) [cosmology, BSM]

frequentist: best–fitting point maxm p(d |m) [flavor]

– LHC era: (1) compute high-dimensional map p(d |m)(2) find and rank local maxima in p(d |m)(3) Bayesian–frequentist dance to reduce dimensions

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Underlying parameters

From kinematics to weak–scale parameters [Fittino; SFitter: Lafaye, TP, Rauch, Zerwas]

– back to question: parameters by weak-scale Lagrangian

– measurements: masses or edges,branching fractions, rates,... [Prospino]

flavor, dark matter, electroweak constraints,...

– errors: general correlation, statistics & systematics & theory [flat theory errors!]

– problem in grid: huge phase space, no local maximum?problem in fit: domain walls, no global maximum?problem in interpretation: bad observables, secondary maxima?

MSUGRA as of today [Allanach, Cranmer, Lester, Weber]

– ‘Which is the most likely parameter point?’

– ‘How does dark matter annihilate/couple?’

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

M1/2 (TeV)

m0

(TeV

)

L/L(max)

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0

0.2 0.4 0.6 0.8

1 1.2 1.4 1.6 1.8

2

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Underlying parameters

Toy model: MSUGRA map from LHC [LHC endpoints with free yt ]

– weighted Markov chains: several times faster [similar to: Ferrenberg & Swendsen]

Pbin(p 6= 0) =N

PNi=1 1/p

– SFitter output #1: fully exclusive likelihood mapSFitter output #2: ranked list of local maxima

– strong correlation e.g. of A0 and yt [including all errors ]

1 10 100 1000 10000 100000

A0

mt

-1000 -500 0 500 1000 1500 2000

160

170

180

190

200 χ2 m0 m1/2 tan β A0 µ mt0.3e-04 100.0 250.0 10.0 -99.9 + 171.4

27.42 99.7 251.6 11.7 848.9 + 181.654.12 107.2 243.4 13.3 -97.4 - 171.170.99 108.5 246.9 13.9 26.4 - 173.688.53 107.7 245.9 12.9 802.7 - 182.7

. . .

⇒ correlations and secondary maxima significant

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Underlying parameters

Toy model: MSUGRA map from LHC [LHC endpoints with free yt ]

– weighted Markov chains: several times faster [similar to: Ferrenberg & Swendsen]

– SFitter output #1: fully exclusive likelihood mapSFitter output #2: ranked list of local maxima

– strong correlation e.g. of A0 and yt [including all errors ]

⇒ correlations and secondary maxima significant

MSSM map from LHC

– shifting from 6D to 19D parameter space [killing grids, Minuit, laptop–style fits...]

– SFitter outputs #1 and #2 still the same [weighted Markov chain plus hill climber]

– three neutralinos observed [profile likelihood]

100

10000

1e+06

1e+08

M1

µ 0 200 400 600 800 1000

-1000

-500

0

500

1000

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Underlying parameters

Toy model: MSUGRA map from LHC [LHC endpoints with free yt ]

– weighted Markov chains: several times faster [similar to: Ferrenberg & Swendsen]

– SFitter output #1: fully exclusive likelihood mapSFitter output #2: ranked list of local maxima

– strong correlation e.g. of A0 and yt [including all errors ]

⇒ correlations and secondary maxima significant

MSSM map from LHC

– shifting from 6D to 19D parameter space [killing grids, Minuit, laptop–style fits...]

– SFitter outputs #1 and #2 still the same [weighted Markov chain plus hill climber]

⇒ secondary maxima degenerate in MSSM

Theorists’ goal [SFitter + Kneur]

– unification and supersymmetry

– test mass unification with errors [Cohen, Schmalz]

– properly: RGE running bottom–up

⇒ LHC: fundamental physics from weak scale 0.002

0.004

0.006

0.008

0.01

2 4 6 8 10 12 14 16 181/

Mi

log(Q)

M1M2M3

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Spin from cascades

What kind of mass term? [Barger,...; Barnett,...; Baer,...]

– gluino = strongly interacting Majorana fermion

– first jet (q or q) fixes lepton charge

– same–sign dileptons in 1/2 of events

– similar: t-channel gluino in pp→ qq– refined: Dirac gluino mass term [Nojiri, Takeuchi]

⇒ like–sign dileptons in SUSY sample means gluino

g u χ+ χ0

µ+

g u* χ−

µ−

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Spin from cascades

What kind of mass term? [Barger,...; Barnett,...; Baer,...]

– gluino = strongly interacting Majorana fermion

– first jet (q or q) fixes lepton charge

– same–sign dileptons in 1/2 of events

– similar: t-channel gluino in pp→ qq– refined: Dirac gluino mass term [Nojiri, Takeuchi]

⇒ like–sign dileptons in SUSY sample means gluino

g u χ+ χ0

µ+

g u* χ−

µ−

New physics is hypothesis testing [Barr, Lester, Smillie, Webber]

– loop hole: ‘gluino is Majorana if it is a fermion’

– gluino a fermion?

– assume gluino cascade observed

– model–independent analysis unlikely

– straw-man model where ‘gluino’ is a boson: universal extra dimensions[spectra degenerate — ignore; cross section larger — ignore; higher KK states — ignore; Higgs sector — ignore]

⇒ compare angular correlations

g

b~ χ2

oµ~

χ1o

bb µ

µ

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Spin from cascades

What kind of mass term? [Barger,...; Barnett,...; Baer,...]

– gluino = strongly interacting Majorana fermion

– first jet (q or q) fixes lepton charge

– same–sign dileptons in 1/2 of events

– similar: t-channel gluino in pp→ qq– refined: Dirac gluino mass term [Nojiri, Takeuchi]

⇒ like–sign dileptons in SUSY sample means gluino

Gluino–bottom cascade [Alves, Eboli, TP; like Cambridge squarks]

– decay chain from gluino mass [simulated for SUSY]

– compare SUSY with excited KK g, b, Z , `, γ

– below edge: mbµ/mmaxbµ = sin θ/2

g

b~ χ2

oµ~

χ1o

bb µ

µ

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Spin from cascades

What kind of mass term? [Barger,...; Barnett,...; Baer,...]

– gluino = strongly interacting Majorana fermion

– first jet (q or q) fixes lepton charge

– same–sign dileptons in 1/2 of events

– similar: t-channel gluino in pp→ qq– refined: Dirac gluino mass term [Nojiri, Takeuchi]

⇒ like–sign dileptons in SUSY sample means gluino

Gluino–bottom cascade [Alves, Eboli, TP; like Cambridge squarks]

– decay chain from gluino mass [simulated for SUSY]

– compare SUSY with excited KK g, b, Z , `, γ

– below edge: mbµ/mmaxbµ = sin θ/2

– better: asymmetry b vs. b [independent of production]

A(mbµ) =σ(b`+)− σ(b`−)

σ(b`+) + σ(b`−)

– stable w.r.t production channels and cuts

– less cool: angle between b and b [3-body decays: Csaki,...]

⇒ SUSY = gluino = fermionic like-sign dileptons

0

0.2

0.4

0 50 100 150 200 250 300 350

SUSY bl-

bl+all cuts

mbl± [GeV]

dσ/d

mbl

± [f

b/G

eV]

0

0.2

0.4

0 50 100 150 200 250 300 350

UED bl-

bl+all cuts

mbl± [GeV]

dσ/d

mbl

± [f

b/G

eV]

-0.5

0

0.5

100 125 150 175 200 225 250 275 300 325 350

SUSY(e~+µ

~+τ

~)

UED(e(1)+µ(1)+τ(1))

L = 600 fb-1SPS1a

Mass Spectrumall cuts

mbl± [GeV]

A± =

(σ(b

l+ )-σ(

bl- ))

/sum

-0.5

0

0.5

100 125 150 175 200 225 250 275 300 325 350

SUSY(e~+µ

~+τ

~)

UED(e(1)+µ(1)+τ(1))

L = 600 fb-1SPS1a

Mass Spectrumbasic cuts

mbl± [GeV]

A± =

(σ(b

l+ )-σ(

bl- ))

/sum

-0.5

0

0.5

100 125 150 175 200 225 250 275 300 325 350

q~ g~ sample

g~ g~ sample

UED

SPS1aMass Spectrum

all cutsL = 200 fb-1

mbl± [GeV]

A± =

(σ(b

l+ )-σ(

bl- ))

/sum

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Spin from cascades

What kind of mass term? [Barger,...; Barnett,...; Baer,...]

– gluino = strongly interacting Majorana fermion

– first jet (q or q) fixes lepton charge

– same–sign dileptons in 1/2 of events

– similar: t-channel gluino in pp→ qq– refined: Dirac gluino mass term [Nojiri, Takeuchi]

⇒ like–sign dileptons in SUSY sample means gluino

Gluino–bottom cascade [Alves, Eboli, TP; like Cambridge squarks]

– decay chain from gluino mass [simulated for SUSY]

– compare SUSY with excited KK g, b, Z , `, γ

– below edge: mbµ/mmaxbµ = sin θ/2

– better: asymmetry b vs. b [independent of production]

A(mbµ) =σ(b`+)− σ(b`−)

σ(b`+) + σ(b`−)

– stable w.r.t production channels and cuts

– less cool: angle between b and b [3-body decays: Csaki,...]

⇒ SUSY = gluino = fermionic like-sign dileptons

60

80

100

120

140

160

180

200

0 20 40 60 80 100 120 140 160 180

SUSY

UED: α(1) = 0, π/2UED: α(1) = π/4

SPS1aMass Spectrum

L = 100 fb-1

∆Φbb [deg]L

× d

σ/d∆

Φbb

[eve

nts/

bin]

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Spin from cascades

What kind of mass term? [Barger,...; Barnett,...; Baer,...]

– gluino = strongly interacting Majorana fermion

– first jet (q or q) fixes lepton charge

– same–sign dileptons in 1/2 of events

– similar: t-channel gluino in pp→ qq– refined: Dirac gluino mass term [Nojiri, Takeuchi]

⇒ like–sign dileptons in SUSY sample means gluino

Problems with general analysis

– exchange ˜LR in cascade [Goto, Kawagoe, Nojiri]

– UED like strongly mixed sleptons

– test of lepton-wino couplings

– stau mixing [Choi, Hagiwara, Kim, Mawatari, Zerwas]

⇒ hypothesis tests...

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0 50 100 150 200 250 300 350

sleptons R + staussleptons L + stausUED

SPS1aMass Spectrum basic cuts

mbl± [GeV]

A± =

(σ(b

l+ )-σ(

bl- ))

/sum

−0.4 −0.2 0 0.2 0.4

θτ∼ /π

0.1

0.2

0.3

0.4

0.5

(b) <mππ>

PT[π] > 15 GeV

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Spins from jets

More hypothesis testing: spin of LSP [Alwall, TP, Rainwater]

u

u

d

d

χ+1

χ+1

W+

W+

χ01

– Majorana LSP with like-sign charginos?

– hypotheses: like–sign charginos (SUSY)like–sign scalars (scalar dark matter model)like–sign vector boson (like litte Higgs)

– stable for simplicity — chargino kinematics not used [SM backgrounds]

– WBF signal: two key distributions ∆φjj ,pT ,j [like H → ZZ → 4µ or WBF-Higgs]

⇒ distinct WBF signal? [pT ,j ∼ mW , forward jets]

visible over backgrounds? [SUSY–QCD backgrounds dominant]

⇒ long shot, but not swamped by SUSY-QCD

), GeV/c1

(jetTP0 200 400 600 800 1000 1200 1400

) 1(je

tT

/dP

σ dσ

1/

0

0.0005

0.001

0.0015

0.002

0.0025

0.003

0.0035

0.004

0.0045 EW(WBF)

EW (all)

EW (non-WBF)

QCD

)2

, jet1

(jetη∆0 1 2 3 4 5 6 7 8 9 10

) 2, j

et1

(jet

η∆/dσ

dσ1/

0

0.2

0.4

0.6

0.8

1EW(WBF)

EW (all)

EW (non-WBF)

QCD

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Spins from jets

Like-sign scalars instead

– assume stable charged Higgs (type-II two-Higgs doublet model)

– H+H− same as simple heavy H0 [TP, Rainwater, Zeppenfeld; Hankele, Klamke, Figy]

– W radiated off quarks [Goldstone coupling to Higgs]

PT (x, pT ) ∼ 1 + (1− x)2

2x1

p2T

PL(x, pT ) ∼ (1− x)2

xm2

W

p4T

⇒ scalars identified by softer pT ,j

), GeV/c1

(jetTP0 100 200 300 400 500 600 700 800 900 1000

) 1(je

tT

/dP

σ dσ

1/

00.0010.0020.0030.0040.0050.0060.0070.0080.009 + WBFχ+χ

H+H+W’+W’+

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Spins from jets

Like-sign scalars instead

– assume stable charged Higgs (type-II two-Higgs doublet model)

– H+H− same as simple heavy H0 [TP, Rainwater, Zeppenfeld; Hankele, Klamke, Figy]

– W radiated off quarks [Goldstone coupling to Higgs]

PT (x, pT ) ∼ 1 + (1− x)2

2x1

p2T

PL(x, pT ) ∼ (1− x)2

xm2

W

p4T

⇒ scalars identified by softer pT ,j

Like-sign vectors instead

– alternative hypothesis like little Higgs

– start with copy of SM, heavy W ′,Z ′,H′, f ′ [H′ necessary for unitarity, but irrelevant at LHC]

– Lorentz structure reflected in angle between jets

⇒ vectors identified by peaked ∆φjj

)2

, jet1

(jetφ∆0 0.5 1 1.5 2 2.5 3

) 2, j

et1

(jet

φ∆/dσ

dσ1/

00.10.20.30.40.50.60.70.80.9 + WBFχ+χ

H+H+W’+W’+

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Spins from jets

Like-sign scalars instead

– assume stable charged Higgs (type-II two-Higgs doublet model)

– H+H− same as simple heavy H0 [TP, Rainwater, Zeppenfeld; Hankele, Klamke, Figy]

– W radiated off quarks [Goldstone coupling to Higgs]

PT (x, pT ) ∼ 1 + (1− x)2

2x1

p2T

PL(x, pT ) ∼ (1− x)2

xm2

W

p4T

⇒ scalars identified by softer pT ,j

Like-sign vectors instead

– alternative hypothesis like little Higgs

– start with copy of SM, heavy W ′,Z ′,H′, f ′ [H′ necessary for unitarity, but irrelevant at LHC]

– Lorentz structure reflected in angle between jets

⇒ vectors identified by peaked ∆φjj

Heavy fermions in little–Higgs models

– not part of the naive set of WBF diagrams

– huge effect on pT ,j

⇒ well–defined hypothesis mandatory), GeV/c

1(jetTP

0 100 200 300 400 500 600 700 800 900 1000

) 1(je

tT

/dP

σ dσ

1/

0

0.001

0.002

0.003

0.004

0.005SM W+W+

W’+W’+ (quark partners)

W’+W’+ (only W’Z’)

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets

Supersymmetry at the LHC

TeV–scale new physics

– know there is BSM physics

– trust solution of hierarchy problem

– explain dark matter

Theory/Phenomenology in the LHC era

(1) look for solid new–physics signals [missing energy?]

(2) measure weak–scale Lagrangian [highD parameter spaces?]

(3) determine fundamental physics

– test discrete new–physics properties

– construct sensible new–physics hypotheses

– avoid getting killed by QCD

– never talk about CMSSM analyses again

⇒ LHC more than a discovery machine!

TeV–ScaleSupersymmetry

at the LHC

Tilman Plehn

New physics

Supersymmetry

Masses

Parameters

Spin & casacades

Spin & jets