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Mini-review: search for eXtra-Dimensions (XD) and Black Holes at the LHC

Universitetet. i Oslo. CMS. Mini-review: search for eXtra-Dimensions (XD) and Black Holes at the LHC. Samir FERRAG University of Oslo, Norway ATLAS. 32 nd I nternational C onference on H igh E nergy P hysics Beijing, China, 2004.

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Mini-review: search for eXtra-Dimensions (XD) and Black Holes at the LHC

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  1. Universitetet i Oslo CMS Mini-review: search for eXtra-Dimensions (XD) and Black Holes at the LHC Samir FERRAG University of Oslo, Norway ATLAS 32nd InternationalConferenceonHigh EnergyPhysics Beijing, China, 2004

  2. Introduction: motivations for eXtra-Dimensions (XD) Hierarchy problem: EW scale << GUT scale << Planck scale (~102 GeV, ~1016 GeV, ~1019 GeV) Alternative: 1 fundamental scale(~ tens TeV)with1+3+d time-space structure New parameters: number of XD: d, size of each XD MC=1/RC, new Planck scale MP (or MD)… Existing models classified by: -Space-time geometry: factorized (flat) or warped[1][2] - Size of compactified XD: large (eV to keV) or small (TeV), same or different size… - propagating particles into XDs: gravitons, gauge bosons or all (UXD) [3] Phenomenological aspects at LHC: - Low MP: production of gravitons and black holes - Low GUT scale: violation of the logarithmic behaviour of coupling running (aem.w.S) [4] - Compactification: every particle allowed in the XD presents Kaluza Klein excitations in 4D - Strongly warped geometry: new scalar to stabilize the geometry In flat geometry: Goal: sensitivity to XD parameters (signatures and results) following a maximum of approachesand models

  3. Corresponding selection of items -Flat extra-dimensions: -Large extra-dimensions: direct and virtual graviton exchange -TeV-1 extra-dimensions: gauge KK excitations -Low MP effects: black hole production -Warped extra-dimensions: -Randall-Sundrum model: Radion, narrow graviton resonances Also: -Higgs boson in the black hole decay -Gravity-matter interaction in fat brane -Summary and Conclusion Abstract: 12-0852 Abstract: 12-0842 N.Akchurin, et al Fermilab-FN-0752 Abstract: 12-0825 C. Macesano, S. Nandi and M.Rujoiu, hep-ph/0407253 C. Macesano, A. Mitov and S. Nandi, hep-ph/0305029

  4. 100 fb-1 Large XD: direct graviton production • Only gravity in n extra-dimensions of eV size (mm) [5] • Signals [6] Jets + Et, g + Et • Backgrounds • Sensitivity • Source of uncertainties Uncertainty in s(Z+jets) affects the sensitivity • Results on gG are also available

  5. GKK PT > 800 GeV Large XD: Virtual graviton exchange • Signals:[7] • Excess in di-leptons and di-photons mass distribution • Forward-backward asymmetry • Event shape: distribution of gg more central (s-channel) • Sensitivity

  6. 4TeV TeV-1 XD: Kaluza Klein (KK) excitations • Gauge bosons allowed in 1 small XD MC~ TeV-1(2x10-4 fm) [8] • Corresponding KK excitations spectrum in 4D: • Z and g KK excitations:[9] • invariant mass reconstruction  up to MC~5.8 TeV • interference with Drell-Yan  up to MC~9.5 TeV • differentiate with Z’  Forward-Backward asymmetry • W KK excitations:[10] • direct observation  up to MC~6 TeV • indirect observation  up to MC~9 TeV • difficult to distinguich from W’ • gluon KK excitations:[11] • Excess in the dijet Pt distribution up to MC~15 TeV

  7. MGUT~30TeV (4+2)D, R=1/10 Tev-1 MSSM+XD Mc= 4 TeV TeV scale gauge unification • Low GUT scale: • Violation of the expected (MS)SM logarithmic • behaviour of couplings(aem,w,s) [4] • Measurement of aS on a large Pt range by measuring dijets cross section From:[12] • Sensitivity to XD is masked by the uncertainties on the proton structure (PDF) [13] • From Mc~5 TeV (without PDF uncertainties) to less than Mc~2 TeV

  8. ~1Hz Black Holes (BH) • Object confined in radius R < RS [14]  LHC is a Black Hole (BH) factory • Development of a Monte Carlo generator: CHARYBDIS [15] • - evaporation and time evolution • - “grey body” factors (transmission of particles through curved space-time outside horizon) • - Planck phase: few hard jets • Simulation in ATLAS: [16] • - cut on the event shape (sphericity) • - mBH reconstructed for each event • - #XD deduced from TH, mBH and MP (Hawking formula)

  9. Planck brane SM brane Warped geometry: radion in Randall-Sundrum model • 1 XD with non factorizable geometry: [1] 5-D Planck scale New physics scale in SM brane: , • Phenomenology: (Radion) [17] • -scalar field to stabilize the distance between branes [18] • -coupling similar to Higgs, mixes with Higgs ( parameter) • -narrow width • Analysis in ATLAS: [19] • -signal and • -background: • Sensitivity: (30 fb-1) -1st channel: 1.0 TeV for mf = 600 GeV -2nd channel: 2.2 TeV (0.6 TeV) for mf= 300 (600GeV)

  10. Warped Geometry: narrow graviton resonance • KK graviton excitations G(k) • -scale  • -coupling & width: c = k/MPl • -0.01 < k/MPl < 0.1 • -mass spectrum: • Golden channel: G(1) e+e- [20] • Signal: • from gluon fusion • 1 – cos4* • from quark annihilation • 1 – 3cos2* + 4cos4* Spin-1 (Z ‘): 1 + cos2* 100 fb-1, mG= 1.5 TeV, c = 0.01 Drell-Yan SM

  11. Higgs boson from the black hole decay[21] Any dijet system • polar angle in Higgs center of mass: • scattering angle for parton subprocess: From Higgs decay • separation between the two jets: • High production rate of BH + democratic decay of BH: • MP~ 2 TeV and n=3 XDs sBH= 450 pb 1light Higgs every 3 sec • Event samples: 50k (100k) of Higgsbb with mH=130 (150) GeV/c2 (Truenoir/Pythia) • CMS full simulation and reconstruction programmes (OSCAR/ORCA) • Unusual kinematics of the BH event: (large total energy, large total Et,high multiplicity of • hard jets, high multiplicity of large Et leptons and large Et Higgs) • b-tagging efficiency decreases with increasing jet energy + Calorimeter resolution •  Additional cuts were developed:

  12. mH=130GeV W/Z mH=150GeV Higgs boson in the black hole decay: results Significance: mH=130 GeV and For 100 pb-1: S=8.4s with b-tagging 100% efficient S=7.4s without b-tagging mH=150 GeV: (Br(Hbb) = 17% only) needs 4.8 fb-1 of integrated luminosity for the same significance

  13. Pair of KK Single KK MP=5TeV Universal eXtra-Dimensions (UXD) in fat brane • Universal extra-dimensions in fat brane: • -gravity in n large XDsof size ~eV to ~keV (~mm to ~mm) • -standard matter in small fraction of size ~TeV of a large XD • Gravity-matter interaction rules in UXD with fat brane: [22] • -KK number is violated in gravity-matter interaction • -gravitation coupling is reduced by the fat brane • -fat brane reduces the dependence on cut-off (MP) in calculations (KK summations) • -the results are valid for a large class of models • Phenomenology from KK number violation: [23] • -decay of 1st KK level (stable in universal extra-dimensions) • gravitationnal decay width was computed • -single KK production Large phase space s^ >2M Constraint: MP close to M

  14. Background: • W+2jets, Z+2jets, , multijet+Et • Cuts:large Pt and Et • Ptjet1 ,Ptjet2 > Ptcutand Et >k . Ptcut k=1,2 or 3 Ptcut=600 GeV k=3 100 evts 20 evts N=6 N=2 MP(TeV) Universal extra-dimensions in fat brane: single KK • Signal: KK  2 jets+Et [23] • parton+parton parton+ parton*Graviton+parton • Sensitivity: up-to7 TeVin KK mass(or MC) Drop fastly with Mp

  15. Summary and Conclusion • Hierarchy problem: • eXtra-Dimensions provide a possible solution and bring down the Planck scale • Sensitivity reach: • invariant mass: ~6 TeV • interference: ~9 TeV • Et: ~9 TeV • ... • If they exist at the LHC energies and are like we understand them today (flat or warped • geometry, large or small size XDs,black holes, universal extra-dimensions, dark matter....) • LHC experiments are able to probe them, or put a limit on them at least.

  16. References [1] L. Randall and R. Sundrum, Phys.Rev.Lett. 83 (1999) 3370 (hep-ph/9905221) [2] Arkani-Hamed, Dimopoulos and Dvali Phys.Lett. B429 (1998) 263; I. Antoniadis, PL B246 (1990) 377 [3] C. Macesanu, CD McMullen and S. Nandi PR D66 (2001) 015009 [4] K.R. Dienes, E. Dudas and T. Gherghetta, Nucl.Phys. B537 (1999) 47 [5] Giudice, Rattazzi & Wells, Nucl.Phys. B544 (1999) 3 (hep-ph/9811291) [6] L. Vacavant and I. Hinchliffe, J. Phys. G: Nucl. Part. Phys. 27 (2001) 1839 [7] V. Kabachenko, A. Miagkov, A. Zenin ATL-PHYS-2001-012, O.J.P. Éboli et al., Phys. Rev. D61 094007 (2000) [8] I. Antoniadis, PL B246 (1990) 377;J. Lykken and S. Nandi, PL B485 (2000) 224 [9] G. Azuelos and G. Polesello BSM report, Proceedings of Les Houches 2001 [10] G. Polesello et M. Prata EPJDirect (SN-ATLAS-2003-036) [11] C.Balazs, M.Escalier, S. Ferrag, B. Laforge, G.Polesello, BSM report,Proceedings of Les Houches 2003 [12] C. Balázs, B. Laforge, Phys.Lett. B525 (2002) 219 (hep-ph/0110217) [13] S. Ferrag, Compte rendu des rencontres de Moriond 2003, hep-ph/0407303 [14] Dimopoulos and Landsberg, hep-ph/0106295 [15] CM Harris, P. Richardson and BR Webber, JHEP 0308 (2003) 033 (hep-ph/0307305: [16] T. Yamamura, J. Tanaka, S.Asai, J.Kanzaki ATL-PHYS-2003-037 [17] G. Giudice, R. Rattazzi, J.D. Wells hep-ph/0002178 [18] Goldberger and Wise (PRL 83 (1999) 4922) [19] G.Azuelos, D. Cavalli, H. Przysiezniak, L. Vacavant SN-ATLAS-2002-019 [20] B.C. Allanach, K.Odigari, A. Parker, B. Webber JHEP 9 19 (2000) [21] N.Akchurin, J.Damgov, D.Green, S.Kunori, G.Landsberg, J.Marrafino, R.Vidal, H.Wenzel, W.Wu, Fermilab-FN-0752 [22] C. Macesano, A. Mitov and S. Nandi, hep-ph/0305029 [23] C. Macesano, S. Nandi and M.Rujoiu, hep-ph/0407253

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