TeV–Scale Supersymmetry at the LHC Tilman Plehn New physics Supersymmetry Masses Parameters Spin & casacades Spin & jets TeV–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 & 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