1. Physics at the LHC Monday: The standard model and QCD@LHC
LHC and the Detectors
Tuesday:
The Higgs Boson (theory)
The Top Quark (Arnaud Lucotte, LPSC)
Wednesday
The Higgs Boson (exp)
Higgs+SUSY (theory)
Thursday
11:00 LHCb (Frederic Machefert, LAL)
13:30 Higgs+SUSY (exp)
Friday
Xtra Dimensions (Gregory Moreau, LPT)
Exotics (Fabienne Ledroit, LPSC)

2. Supersymmetry Fermion Boson
has “no” problems with radiative corrections (quadrat. Div.)
has a light Higgs boson (<135GeV)
promises exciting phenomenology at the TeV scale
The parameters of the Higgs sector:
mA : mass dof the pseudoscalar Higgs Boson
tanβ: ratio of the vacuum expectation values
mass of the top quarks
stop (tR, tL) sector: masses and mixing ~ ~
3 neutral Higgs bosons: h, A, H
1 charged Higgs boson: H±
and supersymmetric particles:
Many different models:
MSSM (minimal supersymmetric extension of the SM, parameter EW Scale)
mSUGRA (minimal supergravity, GUT Scale)
GMSB
AMB
NMSSM
spin-0
spin-1/2
spin-1
Squarks:
qR, qL q
Gluino: g g
Sleptonen:
ℓR, ℓL ℓ
h,H,A
Neutralino χi=1-4
Z, γ H±
Charginos:χ±i=1-2 W± ~ ~ ~ ~ ~
Conservation of R-parity
production of SUSY particles in pairs
(Cascade-) decays to the lightest SUSY particle
LSP stable, neutral and weakly interacting: Neutralino (χ1)
experimental signature: missing ET

3. Supersymmetry Unification of coupling constants
Allanach et al, hep-ph/
Supersymmetrie breaking:
mSUGRA: 5 parameters GUT scale
MSSM: 24 parameters
electroweak Scale
ES-Skala 102GeV
GUT 1016GeV
LEP: mH>114GeV
Electroweak Fit: mH<153GeV
(top mass, W-mass, sin2θW….)
LEP:
M(sparticles) > GeV
Low tanβ excluded by Higgs search

4. SPS1a “typical” example of a supersymmetric spectrum
m0 = 100GeV m1/2 = 250GeV A0 = -100GeV tanβ = sign(μ)=+
favourable for LHC and ILC (Complementarity)
Moderately heavy gluinos and squarks
“Physics Interplay of the LHC and ILC”
Editor G. Weiglein hep-ph/
Heavy and light gauginos ~
τ1 lighter than lightest χ± :
χ± BR 100% τν
χ2 BR 90% ττ
cascade:
qL  χ2 q  ℓR ℓ q  ℓ ℓ qχ1
visible ~ ~ ~ ~
Higgs at the limit
of LEP reach
light sleptons

5. Higgs Bosons in the MSSM
Basic question: is the “abstract” parameter space covered completely?
Red. HWW, HZZ with tanβ
A/Hbb, A/Hττ, A/Hμμ >with tanβ
A/H ττ, μμ; H+ τν, tb
ATLAS preliminary
CMS: bbH/Abbττ
mH=200GeV, 30fb-1, tanβ>20 covered

6. The charged Higgs boson
mH± < mt : (~10pb)
t H±b  τνb (hadronic decay 50%, 100)
10fb-1: 700 signal, 1000 bg
mH± > mt, ggtbH± reco t, W  jj, large ETmiss
Charged Higgs to tau
tbH±, H±  tb:
Very sensitive to syst uncertainties
Backgrounds:
ttj, ttb, ttjj, ttbb
Additional jets
non-αS
Charged Higgs in top decay

7. The Higgs bosons in the MSSM
Plane completely covered with at least 1 Higgs boson visible everywhere
SLHC: can reduce the region of “1 Higgs a little bit”
LEP2: excludes low tanβ range

8. Supersymmetry: Higgs and SUSY
Higgs bosons invisible (=neutralinos)
ZHll+inv
Analysis: 2l, Etmiss, jet-veto, b-jet veto
Background:
tt, ZZ, WZ, ZZ+jets
Higgs bosons in SUSY cascades
Signal to noise ratio: OK (better than SM )
But very model dependent
BRinvisible
excluded
VBF: best channel, but: trigger?

9. Supersymmetry: Squarks and Gluinos
Signature: multi-jet with missing ET
effective mass
Missing ET
SM background also has jets….
SUSY SM
The old plot

10. Supersymmetry: Squarks and Gluinos
Cross sections
Cross sections large:
“easy” discovery in inclusive channels
10fb-1 ~ 2TeV

11. Supersymmetry Electroweak Production: χ02χ1lνχllχ (l=e,μ)
Background:
Drell-Yan, Z+Jets,tt, WZ
Focus Point:
m0=3500GeV
m1/2=300GeV
tanβ=10
A0=0
Search for Gluinos
gluinotbχ,ttχ
Untergrund: tt
S/sqrt(B) ~ 7
gluinottχ
10fb-1

12. Supersymmetry: Masses
Long cascades
Jet-Lepton, Lepton-Lepton, Lepton-Lepton-Jet are functions of the masses
Analysis:
at least 4 jets
PT1>150GeV, 100GeV, 50GeV
Meff>600GeV, Etmiss<max(100,20%Meff)
Leptons: 2 opposite sign same flavour (OSSF) (ee)
background subtraction (SUSY) with OSOF (eμ)

13. Supersymmetry: Masses
Mass determination for 300fb-1 (thus 2014) LHC:
Toy MC from edges, thresholds to masses
Next:
Selected
mll near edge: χ at rest
P(χ2) = (1-m(χ1) /mll) P(ll)
2b-tagged jets
m(χbb) versus m(χb) (2 entries per event)
Select m(χbb) < m(χb) + 150GeV

14. Supersymmetry: Masses
Next determine the gluino mass:
380GeV<mχb < 600GeV
Mχbb is then the gluino mass
Next get the sbottom mass(es):
Background small
Dominant error: energy scale
Difficult to extract the two masses

15. Supersymmetry: Masses and spin
Neutralino2 to stau:
Stau decays to tau
reconstruction 50% efficient (hadronic channel)
Jet-rejection: 1/100
endpoint sensitive to stau mass (same as ll edge)
events in edge used to measure branching ratio of slepton to stau?
Many open questions:
spin (long decay lq mass?)
number of sparticles
completeness of spectrum
majorana nature of gluinos…
is all of this generalizable?

16. Masses: The final word Masses: threshold cross section measurement 2mμ~
Polesello et al: use of χ1 from ILC (high precision) in LHC analyses improves the mass determination

17. Determining the underlying parameters
Transform (s)particle properties to fundamental parameters:
mSUGRA (top-down) and MSSM (bottom-up) with conservation of R-parity
Beenakker et al
need predictions for all observables matching theoretical and experimental precision
observables sensitive to several parameters: correlations, error propagation
Brain power and sophisticated tools:
Mass spectra generated by SOFTSUSY, SUSPECT, SPHENO
Branching ratios by MSMLIB, SPHENO, SDecay
e+e- cross sections (polarized) by SPHENO
NLO proton cross sections by Prospino2.0
Putting it all together (error propagation, search for minima etc):
FITTINO and SFITTER
P. Skands et al., SUSY Les Houches accord (SLHA), Interfacing SUSY spectrum calculators, decay packages, and event generators, JHEP 0407 (2004) 036

18. Lagrangian@GUT scale: mSUGRA
mSUGRA advantage: few parameters, testing ground for studies of principles
disadvantage: starts at GUT scale and adds RGE extrapolation, not the most general Lagrangian
SPS1a
Start m0
100
1TeV
m1/2
250
tanβ 10 50 A0
-100
0GeV
Sign(μ) fixed
Two separate questions:
do we find the right point?
need and unbiased starting point
what are the errors?
Fittino:
start from tree level formula
MINUIT
Simulated Annealing
~300 toy experiments: convergence OK with MINUIT alone for LHC (largest errors)!

19. Lagrangian@GUT scale: the precision for mSUGRA
SPS1a
ΔLHC
ΔILC
ΔLHC+ILC m0
100
3.9
0.09
0.08
m1/2
250
1.7
0.13
0.11
tanβ 10
1.1
0.12 A0
-100 33
4.8
4.3
Sign(μ) fixed
errors on errors typically ~10%
Toy datasets (Gaussian Smearing)
perform ~1000 experiments
errors from LHC %
errors from ILC 0.1%
LHC+ILC: slight improvement
low mass scalars dominate m0

20. Masses versus Edges (LHC)
SPS1a
ΔLHC masses
ΔLHCedges
ΔLHC top1GeV m0
100
3.9
1.2
1.28
m1/2
250
1.7
1.0
tanβ 10
1.1
0.9 A0
-100 33 20 24
top
175 -
0.8
Sign(μ) fixed
use of edges improves parameter determination!
edges to masses is not a simple “coordinate” transformation:
Δm0
Effect on mℓR
Effect on mℓℓ
1GeV
0.7/5=0.14
0.4/0.08=5
Similar effect for m1/2
need correlations to obtain the ultimate precision from masses
the standard model is important: top quark mass precision LHC has a non-negligeable impact on SUSY parameter determination (ILC needs order of magnitude: mtop~0.12GeV affects A0….)

21. And the theory in all that?
Theoretical errors (mixture of c2c and educated guess):
Higgs
sleptons
Squarks,gluinos
Neutralinos, charginos
3GeV 1% 3%
Higgs error: Sven Heinemeyer et al.
Including theory errors reduces
sensitivity by an order of magnitude
SPS1a
ΔLHC+ILCexp
ΔLHC+ ILCth m0
100
0.08
1.2
m1/2
250
0.11
0.7
tanβ 10
0.12 A0
-100
4.3 17
Important task SPA project: precision of theoretical calculations

22. The LHC neutralino enigmaχ1
97.2
4.8 χ2
180.8
4.7 χ3 -- χ4
381.9
5.1
Declaration of bias: 2/3 of Sfitter are in ATLAS, but:
LHC measures the neutralino index????
permute: χ4 with χ3
SPS1a
LHCmasses
ΔLHCmasses
LHCedges
ΔLHCedges m0
100
99.6 4
100.3
2.6
m1/2
250
250.1
1.7
248.8
2.1
tanβ 10
8.1
0.8
7.7
0.73 A0
-100
-196 30
-186 39
top
175 1
175.5
0.75
χ2/p.d.f -
0.2/16
2/11
Exchanging chi3 and chi4 leads to a secondary minimum
M0 and M1/2 ok, but tanbeta and A0 more than 2-3σ from nominal values
so in principle need ILC to see which neutralino are present….
the predicted mass of χ4 is about 400GeV
the predicted branching ratios would lead us to expect more χ4 than χ3 in the measurement channel
general rule: beware of the “hidden” measurements……

23. SLHC+ILC
A likely scenario is concurrent running ILC plus luminosity upgrade of LHC
SLHC
0.08
4.3 3
3.8
2.1
0.5
0.8
1.8 6
5.3
1.1
SPS1a results LHC 300fb-1
SLHC 3000fb-1
Some improvement
limitation: energy scale
SPS1a
ΔLHC before
ΔSLHC
ΔLHC+ILC
ΔSLHC+ILC m0
100
1.2
0.7
0.08
0.07
m1/2
250
1.0
0.6
0.11
tanβ 10
0.9
0.12 A0
-100 20
4.4
3.8
SLHC:
factor 2 improvement
SLHC+ILC marginal wrt LHC+ILC

24. Connection LHC-Cosmology
The universe:
Dark energy 73%
atoms 4%
cold dark matter (CDM) 23%
NASA/WMAP science team
LSP:
massive
weakly interacting
SPS1a: χ1 ideal candidate for CDM
SUSY breaking parameters (determined)
masses and couplings (calculated)
micrOMEGAs (Bélanger et al.): ΩCDMh2=nLSP*mLSP (relic density)
Temperature range: ±200μK
Measurement of the fluctuations of the cosmic microwave background
WMAP
ΩCDMh2=0.127±0.01 (astro-ph/ )
Planck
ΩCDMh2 ~ 2%
LHC : Ωh2 = 0.0033
LHC+ILC: Ωh2 = 0.0003
Win an order of magnitude (Theory errors!)

25. MSSM ILCLHC CLICLHC CLIC LHC ILC MSSM which MSSM??
24 parameters at the EW scale
SFitter choice: do not unify 1st and 2nd generation: data should tell us …
LHC or ILC alone:
certain parameters must be fixed
LHC+ILC:
all parameters fitted
several parameters improved
CLIC wrt ILC:
no fixed parameters with good precision
LHC+CLIC
improvement essentially in the squark sector with factor 2-3 on errors as expected from the mass measurement improvement wrt LHC
Note: if at LHC mSUGRA has a secondary minimum, MSSM will have even more…..

26. Extrapolation to the High Scale
130 % / 180 % Ab precision:
50 % Ab precision:
Blair et al.,
Fittino with W. Porod:
extrapolation shows unification of soft breaking params
Ab difficult to measure, search for new observables

27. Summary Higgs: at least one Higgs boson can be found everywhere
additional Higgs channels open
squarks and gluinos: clearest signal
tri-lepton signal difficult
Above all that: it’s difficult, exciting, therefore hope for an early discovery of SUSY at the LHC soon…..