1. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 20091 Search for Extra Dimensions with CMS Detector at the LHC Sergei Shmatov Joint Institute for Nuclear Research, Dubna for CMS Collaborations  Theoretical Motivations  Models Considered  Signals and Uncertainties  Discovery limits for ED (L ED, TeV -1 ED, RS, UED)  Model Discrimination  Conclusions  Theoretical Motivations  Models Considered  Signals and Uncertainties  Discovery limits for ED (L ED, TeV -1 ED, RS, UED)  Model Discrimination  Conclusions

2. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 20092 Theoretical Motivations  Hierarchy Problem: Gravity/EW ~ 10 19 /10 2 GeV? Why gravitational Interaction is so weak?  Yukawa hierachy (explanation of mass patterns for quarks and leptons)  Unification of interactions  Number of Generations (why 3?) Ways to solve the “naturalness” problem:  Supersymmetry assumes symmetry between fermionic and bosonic fields   EW and strong interactions are unified at 10 16 GeV  must be broken at low energy (? TeV)  will be probably found at LHC Hierarchy is fixed (theory is stabilized), but is not solved (two energy scales still remain) … Can not yet describe Gravity, evolution of Universe …  Technicolor: confinement  problem of strong coupled resonance masses  Compositeness: arbitrariness with a new energy scale  Extra Dimensions  Hierarchy Problem: Gravity/EW ~ 10 19 /10 2 GeV? Why gravitational Interaction is so weak?  Yukawa hierachy (explanation of mass patterns for quarks and leptons)  Unification of interactions  Number of Generations (why 3?) Ways to solve the “naturalness” problem:  Supersymmetry assumes symmetry between fermionic and bosonic fields   EW and strong interactions are unified at 10 16 GeV  must be broken at low energy (? TeV)  will be probably found at LHC Hierarchy is fixed (theory is stabilized), but is not solved (two energy scales still remain) … Can not yet describe Gravity, evolution of Universe …  Technicolor: confinement  problem of strong coupled resonance masses  Compositeness: arbitrariness with a new energy scale  Extra Dimensions

3. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 20093 Model Considered  Large flat Extra-Dimensions (ADD model)  Extra dimensions are flat and could be as large as a few  m  SM particles restricted to 3D brane  only accessible to gravity  Randall-Sundrum (RS1 – two branes)  Small extra spatial dimensions  Curved bulk space (AdS 5 - slice)  Well separated graviton mass spectrum  TeV -1 Extra dimension Model  Bosons could also propagate in the bulk  Fermions are localized at the same (opposite) orbifold point: destructive (constructive) interference between SM gauge bosons and KK excitations  Universal Extra Dimensions  All SM particles propagate in Extra Dimensions  often embedded in large Extra Dimensions  Large flat Extra-Dimensions (ADD model)  Extra dimensions are flat and could be as large as a few  m  SM particles restricted to 3D brane  only accessible to gravity  Randall-Sundrum (RS1 – two branes)  Small extra spatial dimensions  Curved bulk space (AdS 5 - slice)  Well separated graviton mass spectrum  TeV -1 Extra dimension Model  Bosons could also propagate in the bulk  Fermions are localized at the same (opposite) orbifold point: destructive (constructive) interference between SM gauge bosons and KK excitations  Universal Extra Dimensions  All SM particles propagate in Extra Dimensions  often embedded in large Extra Dimensions

4. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 20094  Di-lepton, di-jets and di-photon resonance states (new particles) in RS1-model (RS1-graviton) and TeV -1 extra dimension model (Z KK )  Di-leptons, di-jets continuum modifications (virtual graviton production in ADD)  Single Jets/Single Photons + Missing E T (direct graviton production in ADD)  Single Leptons + missing E T in W KK decays in TeV -1 extra dimension model (W KK )  Back-to-back energetic jets + Missing E T (UED)  4 jets + 4 leptons + Missing E T (mUED)  Di-lepton, di-jets and di-photon resonance states (new particles) in RS1-model (RS1-graviton) and TeV -1 extra dimension model (Z KK )  Di-leptons, di-jets continuum modifications (virtual graviton production in ADD)  Single Jets/Single Photons + Missing E T (direct graviton production in ADD)  Single Leptons + missing E T in W KK decays in TeV -1 extra dimension model (W KK )  Back-to-back energetic jets + Missing E T (UED)  4 jets + 4 leptons + Missing E T (mUED) Experimental Signals

5. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 20095 Total weight 12 500 t Overall diameter 15.00 m Overall length 21.6 m Magnetic field 4 Tesla Large general-purpose particle physics detector Compact Muon Solenoid Detector subsystems are designed to measure: the energy and momentum of photons, electrons, muons, jets, missing E T up to a few TeV

6. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 20096 Experimental Uncertainties  Energy MisCalibration  performance of e/  /hadron energy reconstruction.  Misalignment effect  increase of the mass residuals by around 30%  Drift time and drift velocities  Magnetic and gravitational field effects  can cause a scale shift in a mass resolution by 5-10%  Pile-up  mass residuals increase by around 0.1–0.2 %  Background uncertainties (variations of the bg. shape)  a drop of about 10-15% in the significance values  Trigger and reconstruction acceptance uncertainties  Energy MisCalibration  performance of e/  /hadron energy reconstruction.  Misalignment effect  increase of the mass residuals by around 30%  Drift time and drift velocities  Magnetic and gravitational field effects  can cause a scale shift in a mass resolution by 5-10%  Pile-up  mass residuals increase by around 0.1–0.2 %  Background uncertainties (variations of the bg. shape)  a drop of about 10-15% in the significance values  Trigger and reconstruction acceptance uncertainties

7. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 20097 Theoretical Uncertainties  QCD and EW high-order corrections (K factors)  Parton Distribution Functions (PDF)  Hard process scale (Q 2 )  Cut efficiency, significance estimators..  QCD and EW high-order corrections (K factors)  Parton Distribution Functions (PDF)  Hard process scale (Q 2 )  Cut efficiency, significance estimators..

8. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 20098 ADD Model N.Arkani-Hamed, S.Dimopoulos, G.Dvali (ADD scenario), Phys.Lett. B429(1998), Nuc.Phys.B544(1999)  The real World is multi-dimensional: n flat - Euclidian - extra spatial dimensions, the maximal total number of dimensions is 3(our) + 6(extra)=9  The fundamental scale is not planckian: M D ~ TeV  We (all of SM forces) live on 3D brane (there is another “parallel” hidden World)  Only gravitons are multi-dimensional N.Arkani-Hamed, S.Dimopoulos, G.Dvali (ADD scenario), Phys.Lett. B429(1998), Nuc.Phys.B544(1999)  The real World is multi-dimensional: n flat - Euclidian - extra spatial dimensions, the maximal total number of dimensions is 3(our) + 6(extra)=9  The fundamental scale is not planckian: M D ~ TeV  We (all of SM forces) live on 3D brane (there is another “parallel” hidden World)  Only gravitons are multi-dimensional A “Parallel” World Our World Excess above di-lepton continuum! Graviton contributions to SM processesReal graviton production Jets + missing E T, γ + missing E T

9. 9 ADD: model restrictions  from measurements of the gravitational potential n = 1 excluded by solar system (verification of the Newton’s law up to R < 0.19 mm)  from supernova SN1987 (graviton emission speeds up the supernova cooling): M D > 30 TeV (n = 2), 4 TeV (n = 3)  from energy spectrum of the diffuse gamma-ray background (CDG) due to G KK  γγ: M D > 110 TeV (n = 2), 5 TeV (n = 3) http://www-cdf.fnal.gov/physics/exotic/r2a/20071213.gammamet/LonelyPhotons/photonmet.html PRL 101:181602 (2008)PRL 97:171802 (2006)

10. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 200910 ADD Discovery limit Real graviton production (momojets): jets + missins E T CMS PAS EXO-09-013 CMS-PAS-EXO-08-001 14 TeV@100pb -1 Discovery reach: M D = 3.58 (2.62) TeV for  = 2 (4) Discovery reach: M D = 3.1 (2.3) TeV for  = 2 (4) 10 TeV@200pb -1 Real graviton production (photons + missins E T ) M D = 1 TeV for 0.1-0.2 fb -1 1.5-2 TeV for 1 fb -1 1.5-2 TeV for 1 fb -1 2- 2.5 TeV for 10 fb -1 2- 2.5 TeV for 10 fb -1 3- 3.5 TeV for 60 fb -1 3- 3.5 TeV for 60 fb -1 CMS NOTE 2006/092

11. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 200911 Virtual graviton production (dimuons) ADD Discovery limit @ 14 TeV 1 fb -1 : 3.9-5.5 ТеV for n=6..3 10 fb -1 : 4.8-7.2 ТеV for n=6..3 100 fb -1 : 5.7-8.3 ТеV for n=6..3 300 fb -1 : 5.9-8.8 ТеV for n=6..3 CMS PTDR 2006 Confidence limits for  two muons in the final state  PYTHIA + CTEQ6L, LO + K=1.30  Full (GEANT-4) simulation/reco + L1 + HLT(riger)  Theoretical uncert.  Misalignment, trigger and off-line reco inefficiency, acceptance due to PDF

12. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 200912 Virtual graviton production (diphotons) ADD Discovery limit @ 10 TeV CMS PAS EXO-09-004

13. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 200913 RS1 Model L.Randall, R.Sundrum (RS1 scenario), PRL83 3370 (1999) L.Randall, R.Sundrum (RS1 scenario), PRL83 3370 (1999) 5D curve space with AdS 5 slice: two 3(brane)+1(extra)+time! Signals: Narrow, high-mass resonance states in di-lepton, di-jet, di-photon events: Signals: Narrow, high-mass resonance states in di-lepton, di-jet, di-photon events: CDF: PRL 102, 091805 (2009)

14. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 200914 RS1 Discovery Limit @ 14 TeV  two muons/electrons in the final state  Bckg: Drell-Yan/ZZ/WW/ZW/ttbar  PYTHIA/CTEQ6L  LO + K=1.30 both for signal and DY  Full (GEANT-4) and fast simulation/reco  Viable L1 + HLT(riger) cuts  Theoretical uncert.  Misalignment, trigger and off-line reco inefficiency, pile-up Di-lepton states CMS PTDR 2006 G1μ+μ-G1μ+μ-G1μ+μ-G1μ+μ- G1e+e-G1e+e-G1e+e-G1e+e- c=0.1 100 fb -1 c=0.01 100 fb -1

15. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 200915  Bckg: QCD hadronic jets  L1 + HLT(riger) cuts RS1 Discovery Limit @ 14 TeV  two photons in the final state  Bckg: prompt di-photons, QCD hadronic jets and gamma+jet events, Drell-Yan e + e -  PYTHIA/CTEQ5L  LO for signal, LO + K-factors for bckg.  Fast simulation/reco + a few points with full GEANT-4 MC  Viable L1 + HLT(riger) cuts  Theoretical uncert.  Preselection inefficiency Di-photon states CMS PTDR 2006 G 1  Di-jet states 5  Discovered Mass: 0.7-0.8 TeV/c 2 CMS PTDR 2006 c=0.1

16. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 200916 RS1 Discovery Limit @ 10 TeV Di-photon states Dielectron states CMS PAS EXO-09-009 CMS PAS EXO-09-006

17. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 200917 TeV -1 Extra Dimension Model I. Antoniadis, PLB246 377 (1990)  Multi-dimensional space with orbifolding (5D in the simplest case, n=1)  The fundamental scale is not planckian: M D ~ TeV  Gauge bosons can travel in the bulk  Fermion-gauge boson couplings can be exponentially suppressed for higher KK-modes  Fundamental fermions can be localized at the same (M1) or opposite (M2) points of orbifold  destructive or constructive interference with SM model I. Antoniadis, PLB246 377 (1990)  Multi-dimensional space with orbifolding (5D in the simplest case, n=1)  The fundamental scale is not planckian: M D ~ TeV  Gauge bosons can travel in the bulk  Fermion-gauge boson couplings can be exponentially suppressed for higher KK-modes  Fundamental fermions can be localized at the same (M1) or opposite (M2) points of orbifold  destructive or constructive interference with SM model m e+e- (GeV) pp  Z1/  1  e + e -

18. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 200918 5  discovery limit of (M1 model) CMS PTDR 2006 Di-electron states (Z KK decays) TeV -1 ED Discovery Limits @ 14 TeV  two electrons in the final state  Bckg: Drell-Yan/ZZ/WW/ ZW/ttabr  PYTHIA/PHOTOS with CTEQ61M  LO + K=1.30 for signals, LO + K-factors for bckg.  Full (GEANT-4) simulation/reco  L1 + HLT(riger) cuts  Theoretical uncert.  Low luminosities pile-up

19. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 200919  Multi-dimensional space with orbifolding (5D in the simplest case, n=1)  The model parameters: compactificaton radius R, cut-off scale , m h  All particles can travel into the bulk  KK parity conservation -> the lightest massive KK particle (LKP) is stable (dark matter candidate).  mass degeneration except if radiative corrections included  Multi-dimensional space with orbifolding (5D in the simplest case, n=1)  The model parameters: compactificaton radius R, cut-off scale , m h  All particles can travel into the bulk  KK parity conservation -> the lightest massive KK particle (LKP) is stable (dark matter candidate).  mass degeneration except if radiative corrections included 600 570 g1g1 Q1Q1 Z1Z1 L1L1 11  SM brane is endowed with a finite thickness in the ED  Gravity-matter interactions break KK number conservation: ● 1st level KK states decay to G+SM. ● If radiative corrections -> mass degeneracy is broken and  and leptons are produced.  SM brane is endowed with a finite thickness in the ED  Gravity-matter interactions break KK number conservation: ● 1st level KK states decay to G+SM. ● If radiative corrections -> mass degeneracy is broken and  and leptons are produced. Universal Extra Dimensions Standard UED Thick brane

20. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 200920 UED Discovery Limit @ 14 TeV Standard UED  4 leptons in the final state + missing p T  Bckg: ttbar + n jets (n = 0,1,2), 4 b-quarks, ZZ, Zbbar  CompHEP for signal and PYTHIA for bckgr. with CTEQ5L  Full simulation/reco + L1 + HLT(riger) cuts  Theoretical and exp. uncert. 1111 l Geo accep L1,HLT 2 OSSF 4 ISO b-tag veto p T l < E T miss Z veto Q1Q1Q1Q1 q p p g1g1g1g1 Q1Q1Q1Q1 q Z1Z1Z1Z1 q L1L1L1L1 l g1g1g1g1 L1L1L1L1 l 1111 l Z1Z1Z1Z1 q CMS-CR-2006/062 CMS AN 2006/008

21. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 200921 Spin-1 States: Z from extended gauge models, Z KK Spin-2 States: RS1-graviton Method: unbinned likelihood ratio statistics incorporating the angles in of the decay products the Collins-Soper farme (R.Cousins et al. JHEP11 (2005) 046). The statististical technique has been applied to fully simu/reco events. Spin-1/Spin-2 Discrimination Angular distributions CMS PTDR 2006 Z’ vs RS1-graviton Z  -model (m Z =1,5 TeV, 168 fb -1 ) RS1 graviton (m Z =1,5 TeV, c=0.1, 134 fb -1 )

22. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 200922 Conclusions CMS analyses cover a large part of different hypotheses proposed to solve a number of problems of Standard Model The discovery potential of both experiments makes it possible to investigate if extra dimensions really exist within various ED scenarios at a few TeV scale:  Large Extra-Dimensions (ADD model)  Randall-Sundrum (RS1)  TeV-1 Extra dimension Model  Universal Extra Dimensions The performance of detector systems allows to perform searches in the different channels  A proper energy, momentum angular reconstruction for high-energy leptons and jets, Et measurement  b-tagging  An identification of prompt photons New results are expected at the start-up LHC @ 10 TeV (integrated luminosity ~ 0.1-0.2 fb -1 ) Many analyses are out of this talk: Black Holes, Bulk Scalars, Singlet Neutrino etc. CMS analyses cover a large part of different hypotheses proposed to solve a number of problems of Standard Model The discovery potential of both experiments makes it possible to investigate if extra dimensions really exist within various ED scenarios at a few TeV scale:  Large Extra-Dimensions (ADD model)  Randall-Sundrum (RS1)  TeV-1 Extra dimension Model  Universal Extra Dimensions The performance of detector systems allows to perform searches in the different channels  A proper energy, momentum angular reconstruction for high-energy leptons and jets, Et measurement  b-tagging  An identification of prompt photons New results are expected at the start-up LHC @ 10 TeV (integrated luminosity ~ 0.1-0.2 fb -1 ) Many analyses are out of this talk: Black Holes, Bulk Scalars, Singlet Neutrino etc.

23. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 200923 Backup slides

24. Sergei Shmatov, Search for Extra Dimensions.., NPD RAS, Moscow, November 23-27, 200924 LHC Expectations @ 14 TeV ModelMass reachIntegrated Luminosity (fb -1 ) Systematic uncertainties ADD Direct G KK M D ~ 1.5-1.0 TeV, n = 3-61Theor. ADD Virtual G KK M D ~ 4.3 - 3 TeV, n = 3-6 M D ~ 5 - 4 TeV, n = 3-6 0.1 1 Theor.+Exp. RS1 di-electrons di-photons di-muons di-jets M G1 ~1.35- 3.3 TeV, c=0.01-0.1 M G1 ~1.31- 3.47 TeV, c=0.01-0.1 M G1 ~0.8- 2.3 TeV, c=0.01-0.1 M G1 ~0.7- 0.8 TeV, c=0.1 10 1 0.1 Theor.+Exp. (only stat. for di-jets) TeV -1 (Z KK (1) )M z1 < 5 TeV1Theor. UED 4 leptons R -1 ~ 600 GeV1.0Theor.+Exp. Thick braneR -1 = 1.3 TeV6 pb -1