1. SUSY and other BSM physics with CMS
G. Bruno on behalf of the CMS Collaboration
Center for Cosmology, Phenomenology and Particle Physics (CP3)
Université catholique de Louvain (UCL), Louvain-la-Neuve, Belgium
LHC Days in Split Conference
30/9/2014

2. The Standard Model puzzles
Higgs boson discovery has completed the SM
Key unanswered questions:
Dark matter
Matter-antimatter asymmetry
Neutrino masses
Gravity and “dark energy”
Unification of forces
Deeper origin of electroweak symmetry breaking
Deeper origin of fermion mass hierarchies, flavor mixing, and CP violation
BSM Physics that would address these questions is in many cases expected at the TeV scale
Split2014 – BSM in CMS

3. BSM physics ideas
Split2014 – BSM in CMS

4. How to search for BSM physics at the LHC
Talks by:
J.-P. Sauvan
A. Nikitenko
F. Pandolfi
Scalar sector
Precise measurements of Higgs couplings and properties
Search for an extended scalar sector
Precise measurement of SM observables
Few, yet notable, competitive examples
Final states with top quarks
Strong and ew couplings
Rare decays
Top squark, vector-like top partners, tt resonances
Other direct searches for new physics
Inclusive squarks and gluino (and neutralino) searches
Compressed SUSY spectra
R-parity violating susy searches
New vector bosons
mono X searches (heavy, strongly interacting states are out of reach)
Long-lived particles
Talks by C. Grab and E. Gallo
Talk by J. Cuevas Maestro
Talk by R. Bartek
Talk by M. Kazana
Split2014 – BSM in CMS

5. Supersymmetry
Split2014 – BSM in CMS

6. SUSY searches Highly motivated theoretical framework
High cross section – gluinos,1st and 2nd generation squarks
Multijets + MET w/wo b-jets, leptons, photons
Highly motivated theoretical framework
Lays the bases for unification of forces
Provides a dark matter candidate
Can stabilize the Higgs mass
Medium cross section – stop and sbottom
Multi-jets + MET + b-tags w/w.o. leptons
Dedicated searches
Low cross section – Charginos, neutralinos, sleptons:
0-4 leptons + METw/w.o. b-tags, jets, W’s, Z’s, h’s
Split2014 – BSM in CMS

7. All-hadronic inclusive search
Gluinos,1st,2nd gen. squarks
36 signal regions in bins of
Jet multiplicity (≥3)
HT (≥500 GeV)
HTmiss (≥200 GeV)
Limits in Simplified Model Space (SMS)
Split2014 – BSM in CMS

8. The search for (natural) stops
Split2014 – BSM in CMS

9. Stop search for moderate mass differences
Combination of 2 analyses (SUS ):
Inclusive search with ETmiss, b-jets w/wo leptons (SUS )
Uses razor variables in several disjoint boxes
Exclusive analysis targeting the bb𝑊𝑊 χ 0 χ 0 final state ( )
BDT selection on events with 1 lepton, ≥4 jets (≥1btagged) and Etmiss
Limits depend on stop decay BRs
Most stringent for BR( 𝑡 →𝑡 χ 0 )=1
Also conservative BR-independent result
Split2014 – BSM in CMS

10. Stop search: filling the gaps
Monojet dedicated analysis (SUS )
ISR can induce high ETmiss and relatively soft charm jets
Etmiss>250 GeV;
pT(j1)>110 GeV
Stops from gluinos ( , )
0/1 leptons, multijets, bjets and ETmiss
Stop1 from stop2 ( )
1-3 leptons, multi-(b)jets and ETmiss optimized for 𝑡 2 → 𝑡 1 𝐻/𝑍
Split2014 – BSM in CMS
Stops from gluinos
Phys. Lett. B 733 (2014) - CMS-SUS (1l multijets and met) ma anche CMS-SUS for gluinos
Phys. Lett. B 725 (2013) - CMS-SUS (0l, multijets,met and bjets)

11. Ewkino searches
Inclusive multileptons, ETmiss w/wo jets search ( )
2/3/4 leptons + ETmiss
2 SS leptons + Etmiss
W(jj)/Z(jj)+Z(ll) + Etmiss
W(lυ)H + ETmiss
Interpretation in several specific SMS
Search targeting hh / hZ / hW + ETmiss ( )
ℎ→𝑏 𝑏 , 𝛾𝛾,𝑍𝑍
Interpretation in scenarios with 𝜒 𝜒 1 ± higgsino or gauginos
Split2014 – BSM in CMS

12. M(l+l-) kinematic edge search
SUS
Generic search for a kinematic endpoint in the invariant mass distribution of OS-SF lepton pairs (e or μ) in events with ETmiss and jets
E.g. 𝜒 2 0 →𝑙 𝑙 → 𝜒 𝑙 + 𝑙 −
Two search regions: central (2l in |η|<1.4) and forward (1l in1.6<|η|<2.4)
Background estimated from OS-OF lepton pairs
Fit the observed distribution with B-only and S+B models
Also cut & count analysis in signal region 20<M( 𝑙 + 𝑙 − )<70 GeV
OS-SF
OS-OF
Cut&Count
Split2014 – BSM in CMS

13. DARK MATTER
Split2014 – BSM in CMS

14. Dark Matter (DM) searches
DM-nucleon scattering (LUX, CDMS, XENON, …)
DM annihilation or decay (Fermi, PAMELA, AMS, IceCube, …)
DM production at colliders
Particularly competitive at low DM masses
DM produced in cascade decays from heavier particles: Supersymmetry, Higgs portal
Direct DM production
Detectable if accompanied by additional objects (e.g. ISR)
Interpretation in terms of Effective Field Theories
Key parameters:
DM mass mDM
Mediator mass M
Interaction type (scalar, vector, axial-vector, tensor)
Couplings 𝑔 𝑞, 𝑔 χ
Split2014 – BSM in CMS

15. Mono-X searches Mono-jet (1408.3583) Mono-γ (EXO-12-047) Mono-𝑡 𝑡
𝑝 𝑇 𝑗 >110 GeV | η 𝑗 |<2.4
𝐸 𝑇 𝑚𝑖𝑠𝑠 >250 GeV
strongest limits on vector and axial-vector interactions
Also on ADD G, unparticles
Mono-γ (EXO )
𝐸 𝑇 𝛾 >145 GeV | η γ |<1.44
𝐸 𝑇 𝑚𝑖𝑠𝑠 >145 GeV
Mono-𝑡 𝑡
Semileptonic (B2G ) and dileptonic analyses (B2G )
Strongest limit on scalar interaction (strength ∝ 𝑚 𝑞 𝑀 ∗ 3 )
Mono-𝑡 (B2G )
Requires FCNC or Baryon number / R-parity violation
Limits set on scalar and vector boson DM produced via FCNC
Split2014 – BSM in CMS

16. Limits on DM MONO-JET: vector (𝑞𝑞χχ) and scalar (ggχχ) interaction
MONO-JET: axial-vector (𝑞𝑞χχ) interaction
MONO-tt: scalar interaction (𝑞𝑞χχ)
Invisible Higgs: scalar, fermion and vector DM
Split2014 – BSM in CMS

17. Mono-W (DM-DM-W production)
If u and d quarks couples differently to DM, interference can make mono-W the dominant process
ξ= λ 𝑢 λ 𝑑 is the relevant parameter
Standard lepton(e or μ) + ETmiss search in the MT spectrum ( )
Sets limits on SSM W’, CI, UED W(n)KK, as well as model-independent ones
Split2014 – BSM in CMS

18. EXTRA-DIMENSIONS, COMPOSITENESS and new BOSONS
Split2014 – BSM in CMS

19. Theoretical context Extra dimensions Compositeness
Address hierarchy problem by extending space-time dimensions (4+δ in ADD variant)
𝑀 𝑃𝑙 ≈ 𝑀 𝐷 δ+2 𝑅 δ (δ dimensions compactified over multidim torus of radius 𝑅)
RS variant: 1 ED and warped space-time
Gravity propagates in all dimensions and appears weak in 4 dim space time
KK excitations of all known SM particles
Can provide dark matter candidates
ADD: non-resonant enhancement
RS: distinct resonant production
Compositeness
Known fermions would be composed of more fundamental constituents interacting via a new strong gauge interaction
At energies smaller than the new interaction scale Λ, it manifests as a contact interaction giving event rate enhancements
Most sensitive searches: di-fermions and mono-X
Split2014 – BSM in CMS

20. Narrow resonances (EXO-12-061)
Dilepton searches
Narrow resonances (EXO )
Shape analysis in the full unbinned di-μ and di-e inv. mass spectra
Enhancement in di-lepton event rates at high mass (EXO , EXO , EXO )
Count events beyond mass threshold
EXO
EXO
Split2014 – BSM in CMS

21. Dilepton searches - limits
Limits from peak search w.r.t. previous 5+5 fb-1 paper ( ):
Z’SSM : 2.59 TeV  2.96 TeV
KK graviton ( 𝑘 𝑀 𝑃𝑙 =0.1): 2.39 TeV  t.b.u.
Limits on MSvs nED in the ADD ED
Limits in the LLIM variant of CI
For both destructive and constructive interference with DY production
Limits on HnCM from “mono-W” search
Split2014 – BSM in CMS

22. FINAL STATES WITH TOP QUARKS
Split2014 – BSM in CMS

23. ttbar invariant mass distribution
Combines semi-leptonic and all-hadronic analyses
All-hadronic: 2 back-to-back top-tagged CA8 jets with pT>400 GeV
Semileptonic: has both resolved (1l,≥4j) and boosted (1l wo isolation, ≥2j) event categories (transition at 𝑀 𝑡 𝑡 ~1TeV )
Subjet identification in boosted category
Background control with 0 btag selection
Results from simultaneous fit to the different 𝑀 𝑡 𝑡 distributions
Split2014 – BSM in CMS

24. Rare top decays FCNC (1312.4194): 𝑡→𝑍𝑞
SM decay BR of order (10-14) occurring via loop diagrams.
RPV susy, warped ED and others predict enhancements up to with large model parameter dependence
Search for 𝑡 𝑡 →𝑍𝑞𝑊𝑏 with leptonic (e or μ) decay for W and Z
BR(𝑡→𝑍𝑞)>5× 10 −4 excluded at 95% CL
BNV ( ): 𝑡→ 𝑏 𝑐 μ + (𝑡→ 𝑏 𝑢 𝑒 + )
Baryon Number (BN) is a conserved quantity in the SM
BN violation necessary condition for matter-antimatter asymmetry in the Universe.
Predicted in RPV susy, and grand unification models
Recent theory paper has noted that the above decay could occur at relatively high rates, preserving proton stability
search for 𝑡 𝑡 →𝑙𝑏𝑏𝑗𝑗𝑗 in electron and muon channel
BR(𝑡→ 𝑏 𝑢 𝑒 + )>1.6× 10 −3 excluded at 95% CL (and similar for muon channel)
Split2014 – BSM in CMS

25. NEUTRINOS
Split2014 – BSM in CMS

26. Search for RH heavy neutrino and W
Search guided by Left-right symmetric SM extensions
Predicts heavy RH W/Z and Majorana neutrinos, explaining neutrino masses through see-saw
Signature with SF leptons:
Shape analysis in the lljj invariant mass spectrum
No distinction between OS and SS leptons
First limits on WR beyond the th. lower limit MWR >2.5 TeV (from KL-KS mass diff.)
2.8 σ local excess in electron channel (only 1 SS pair out of 14 events and no deviation in muon channel)
Split2014 – BSM in CMS

27. Huge spectrum of BSM physics searches performed by CMS
Conclusions
Huge spectrum of BSM physics searches performed by CMS
Overview and personal selection, with some physics guidance, presented in this talk
Ground prepared for the RUNII data analysis
Split2014 – BSM in CMS

28. BACK-UP
Split2014 – BSM in CMS

29. Split2014 – BSM in CMS

30. Split2014 – BSM in CMS

31. Split2014 – BSM in CMS

32. Conclusions
Split2014 – BSM in CMS