1. Recent LHC Results & Implications for New Physics Models
John Ellis
King’s College London & CERN

2. Why do Things Weigh? Where do the masses come from ?
Newton:
Weight proportional to Mass
Einstein:
Energy related to Mass
Neither explained origin of Mass
Where do
the
masses
come from ?
Are masses due to Higgs boson?
(the physicists’Holy Grail)

3. 2011: Combining Information from Previous Direct Searches and Indirect Data
mH = 125 ± 10 GeV
Gfitter collaboration

4. Higgs Production at the LHC
A la recherche du
Higgs perdu …
Higgs Production at the LHC
Many production modes measurable if Mh ~ 125 GeV

5. Higgs Decay Branching Ratios
Couplings proportional to masses (?)
Important couplings through loops:
gluon + gluon → Higgs → γγ
Many decay modes measurable if Mh ~ 125 GeV

6. Has the Higgs been Excluded?
Interesting hints around Mh = 125 GeV ?
ATLAS excludes
< 122.5, > 129, < 539 GeV
CMS excludes
> 127.5, < 600 GeV

7. Has the Higgs been Discovered?
Interesting hints around Mh = 125 GeV ?
CMS prefers
< 125 GeV
ATLAS prefers
> 125 GeV

8. Unofficial Combination of Higgs Search Data from March 7th
Is this the
Higgs Boson?
No Higgs here!
No Higgs here!

9. Be careful what you wish for!

10. The Particle Higgsaw Puzzle
Is LHC finding the missing piece?
Is it the right shape?
Is it the right size?

11. Does the ‘Higgs’ have Spin Zero ?
Decays into γγ, so cannot have spin 1
Spin 0 or 2?
If it decays into ττ or b-bar: spin 0 or 1 or orbital angular momentum
Can diagnose spin via
angular distribution of γγ
angular correlations of leptons in WW, ZZ decays
Does selection of WW events mean spin 0?

12. Does the ‘Higgs’ have Spin Zero ?
Polar angle distribution: X2 γγ
(flat for X0)
Azimuthal angle distribution: X0 WW
(flat for X2)
JE, Hwang: arXiv:

13. Does the ‘Higgs’ have Spin Zero ?
Polar angle distribution for X2 W+W-
Polar angle distribution for X0 W+W-
(for φ = π)
JE, Hwang: arXiv:

14. Measuring Higgs Couplings @ LHC
Current LHC Mh = 125 GeV

15. Flavour-Changing Couplings?
Upper limits from FCNC, EDMs, …
Quark FCNC bounds exclude observability of quark-flavour-violating h decays
Lepton-flavour-violating h decays could be large:
BR(τμ) or BR(τe) could be O(10)%
B BR(μe) must be < 2 ✕ 10-5
Blankenburg, JE, Isidori: arXiv:

16. There must be New Physics Beyond the Standard Model
viXra Blogger’s Combination
of March 7th Data
Precision
Electroweak
data??
Higgs
coupling
blows up!!
Higgs
potential
collapses
Higgs coupling less
than in Standard Model

17. Elementary Higgs or Composite?
Higgs field:
<0|H|0> ≠ 0
Quantum loop problems
Fermion-antifermion condensate
Just like QCD, BCS superconductivity
Top-antitop condensate? needed mt > 200 GeV
Cutoff
Λ = 10 TeV
New technicolour force?
Heavy scalar resonance?
Inconsistent with
precision electroweak data?
Cut-off Λ ~ 1 TeV with
Supersymmetry?

18. Interpolating Models Combination of Higgs boson and vector ρ
Two main parameters: mρ and coupling gρ
Equivalently ratio weak/strong scale:
gρ / mρ
Grojean, Giudice, Pomarol, Rattazzi

19. General Analysis of ‘unHiggs’ Models
Parameterization of effective Lagrangian:
Fits
a ≠ c
Azatov, Contino, Galloway: arXiv:
Espinosa, Grojean, Muhlleitner, Trott: arXiv:

20. Global Analysis of ‘UnHiggs’ Models
Rescale couplings: to bosons by a, to fermions by c
Standard Model: a = c = 1
CMS
JE & Tevong You, arXiv:

21. Global Analysis of ‘UnHiggs’ Models
Rescale couplings: to bosons by a, to fermions by c
Standard Model: a = c = 1
ATLAS
JE & Tevong You, arXiv:

22. Global Analysis of ‘UnHiggs’ Models
Rescale couplings: to bosons by a, to fermions by c
Standard Model: a = c = 1
CDF/D0
JE & Tevong You, arXiv:

23. Combination of LHC & Tevatron
Rescale couplings: to bosons by a, to fermions by c
Standard Model: a = c = 1
Global
JE & Tevong You, arXiv:

24. Combination of LHC & Tevatron
Using signal strengths, not mass measurements
Likelihood in Standard Model as function of Mh
Preference for Mh < 125 GeV, driven by W+W-
Global
JE & Tevong You

25. Theoretical Constraints on Higgs Mass
Large Mh → large self-coupling → blow up at low-energy scale Λ due to
renormalization
Small: renormalization
due to t quark drives
quartic coupling < 0
at some scale Λ
→ vacuum unstable
Vacuum could be stabilized by Supersymmetry
LHC 95%
exclusion
Espinosa, JE, Giudice, Hoecker, Riotto, arXiv

26. Minimal Supersymmetric Extension of Standard Model (MSSM)
Particles + spartners
2 Higgs doublets, coupling μ, ratio of v.e.v.’s = tan β
Unknown supersymmetry-breaking parameters:
Scalar masses m0, gaugino masses m1/2,
trilinear soft couplings Aλ, bilinear soft coupling Bμ
Often assume universality:
Single m0, single m1/2, single Aλ, Bμ: not string?
Called constrained MSSM = CMSSM

27. Non-Universal Scalar Masses?
Different sfermions with same quantum #s?
e.g., d, s squarks?
disfavoured by upper limits on flavour- changing neutral interactions
Squarks with different #s, squarks and sleptons?
disfavoured in various GUT models
e.g., dR = eL, dL = uL = uR = eR in SU(5), all in SO(10)
Non-universal susy-breaking masses for Higgses?
No reason why not! NUHM

28. Possible Nature of LSP No strong or electromagnetic interactions
Otherwise would bind to matter
Detectable as anomalous heavy nucleus
Possible weakly-interacting scandidates
Sneutrino
(Excluded by LEP, direct searches)
Lightest neutralino χ (partner of Z, H, γ)
Gravitino
(nightmare for astrophysical detection)

29. Data Electroweak precision observables Flavour physics observables
gμ - 2
Higgs mass
Dark matter
LHC
MasterCode: O.Buchmueller, JE et al.

30. Searches with ~ 5/fb @ 7 TeV
Jets + missing energy search within CMSSM
Extensions to other models needs
more experimental information, fast simulation tools 30

31. PYTHIA + Delphes Validation
Use ‘best’
ATLAS analysis
@ each point
in parameter space
Reproduces CL along 95% line
in (m0, m1/2) plane
Justifies simple extrapolation
to other values of (m0, m1/2)

32. PYTHIA + Delphes Validation
CL ~ independent
of tan β
CL ~ independent
of A0

33. Limits on Heavy MSSM Higgses

34. Flavour Physics Observables
Inclusion requires additional
hypotheses
E.g., minimal flavour violation
Many anomalies reported
e.g., top production asymmetry, dimuon asymmetry, Bs J/ψ φ, BD(*)τν,
isospin asymmetry in BK(*)μμ
Difficult to interpret in SUSY
Big advances in Bs μ+μ-
Valuable constraint on SUSY models

35. Latest News on Bs  μ+μ- Upper limit ~ 4.5×10-9 nearing Standard Model
In SM, comparison of theory with experiment needs ~ 9% correction because of Bs mixing

36. XENON100 & other Experiments
Aprile et al: arXiv: 36

37. Quo Vadis gμ - 2?
Strong discrepancy between BNL experiment and e+e- data:
now ~ 3.6 σ
Better agreement between
e+e- experiments
Increased discrepancy between BNL experiment and τ decay data
now ~ 2.4 σ
Convergence between e+e- experiments and τ decay
SUSY interpretation in tension with LHC 37

39. Tools do not always agree …
Dark matter
Density in
Region of
Multiple
coannihilations
SSARD
2.76E-09
2.74E-09
5.03E-09
4.14E-09
Bsμ+ μ-
@ large tan β
Third
opinion

40. Favoured values of Mh ~ 119 GeV:
Higgs mass
χ2 price to pay if
Mh = 125 GeV is ~ 2
Buchmueller, JE et al: arXiv:
Favoured values of Mh ~ 119 GeV:
Range consistent with evidence from LHC !

41. p-value of CMSSM ~ 9%, NUHM1 ~ 11%5
Coannihilation,
funnel regions
less disfavoured
68% & 95%
CL contours
--- 1/fb
___ 5/fb
Focus-point region
more disfavoured
CMSSM
NUHM1
Over 100
Over 200
Buchmueller, JE et al: to appear
p-value of CMSSM ~ 9%, NUHM1 ~ 11%

42. Favoured values of gluino mass significantly5
--- 1/fb
___ 5/fb
Gluino mass
CMSSM
NUHM1
Buchmueller, JE et al: to appear
Favoured values of gluino mass significantly
above pre-LHC, > 1.5 TeV

43. Favoured values of squark mass significantly5
--- 1/fb
___ 5/fb
Squark mass
CMSSM
NUHM1
Buchmueller, JE et al: to appear
Favoured values of squark mass significantly
above pre-LHC, > 1.5 TeV

44. Les Houches Recommendations for the Presentation of LHC Results
Guiding Principles:
What has been observed should be clear to a non-collaboration colleague.
How it has been observed should be clear to a non-collaboration colleague.
An interested non-collaboration colleague should be able to use and (re-)interpret results without the need to take up the time of collaboration insiders.
Searches for New Physics: S. Kraml et al., arXiv:

45. Searches for New Physics: S. Kraml et al., arXiv:1203.2489
Recommendations
… The community should identify, develop and adopt a common platform to store analysis databases, collecting object definitions, cuts, …
Provide … efficiency maps …
The community should take responsibility for providing, validating and maintaining a simplified simulation code for public use, reproducing the basic response of the LHC detectors.
… Provide the final likelihood function
Searches for New Physics: S. Kraml et al., arXiv:

46. The Story so far in 2012

47. Conversation with Mrs Thatcher: 1982
What do you do?
Wouldn’t it be better if they
found what
you predicted?
Think of things for the experiments to look for, and hope they find something different
Then we would not learn anything!