1 / 16

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.

brigit
Download Presentation

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

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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

More Related