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Search for Microscopic Black Hole Signatures in the CMS Experiment

Search for Microscopic Black Hole Signatures in the CMS Experiment M. Savina on behalf of CMS Collaboration CMS black hole working group: Brown University, USA: G. Landsberg, A. Ferapontov, P.K.V. Tsang JINR, Russia: V. Konoplianikov , M. Savina, S. Shmatov

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Search for Microscopic Black Hole Signatures in the CMS Experiment

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  1. Search for Microscopic Black Hole Signatures in the CMS Experiment M. Savina on behalf of CMS Collaboration CMS black hole working group: Brown University, USA: G. Landsberg, A. Ferapontov, P.K.V. Tsang JINR, Russia: V. Konoplianikov , M. Savina, S. Shmatov The NPD RAS Conference "The Physics of Fundamental Interactions", November 25, 2011, ITEP, Moscow

  2. In large extra dimension models • Gravity stronger at small distances • Horizon radius larger • For M ~ TeV it increases from 10-38 fm to 10-4 fm • For these BH Rh<< R and they have approximately higher dimensional spherical • symmetry Black Hole formation in TeV-scale gravity Pictures by Sabine Hossenfelder At the LHC partons can come closer than their Schwarzschild horizon black hole production

  3. Evolution stages for BH I. Balding phase Asymmetric production, but “No hair” theorem: BH sheds its high multipole moments for fields (graviton and GB emitting classically), as electric charge and color. Characteristic time is about t ~ RS Result: BH are classically stable objects. Inelasticity. II-III. Hawking radiation phases (short spindown + more longer Schwarzschild) Quantum-mechanical decay trough tunneling, transition from Kerr spinning BH to stationary Schwarzschild one. angular momentum shedding (up to ~ 50% mass loss). Corrections with Gray Body Factors. After this – an entropy; thermal decay to all SM particles with BB energy spectra. Accelerating decay with a varying growing temperature. No flavor dependence, only number of D.o.f.– “democratic” decay IV.Planck phase: final explosion(subj for QGr) BH remnant (non-detectable energy losses), N-body decay, Q, B, color are conserved or not conserved

  4. BH production in pp collisions BH production cross section (S. Dimopoulos, G. Landsberg, Phys.Rev.Lett.87:161602, 2001 hep-ph/0106295v1) PDF’s (MSTW2008lo68, CMS EXO-11-071) Not all initial collision energy actually trapped during BH formation process inelasticity – function of n,b H. Yoshino and Y. Nambu, Phys. Rev. D 67, 024009(2003), gr-qc/0209003; L. A. Anchordoqui,J.L. Feng, H. Goldberg,and A.D. Shapere, hep-ph/0311365

  5. BH decay: Hawking temperature and entropy Hawking temperature (R.C. Myers and M.J. Perry, Ann. Phys. 172, 304, 1986) SBH must be large enough to reproduce thermal BH decay K. Cheung, PRD66, 036007 (2002). (S.B. Giddings, hep-ph/0110127v3, K. Cheung, Phys. Rev. Lett. 88, 221602, 2002) Democratic decay blinded to flavor: probabilities are the same for all species (violation of some conservation laws)

  6. Black Hole or String Ball? K. Cheung, PR D66, 036007 (2002), hep-ph/0305003 MBH >> MD: semiclassical well-defined description for BH’s. What happens when MBH ~ MD? BH becomes “stringy”, their properties complex. Matching: S. Dimopoulos and R. Emparan, Phys. Lett. B526, 393(2002), hep-ph/0108060

  7. BH specifity and experimental signatures • Potentially large cross sections (can be really suppressed by factors coming • from production process details) • Increasing cross sections with an energy, according to an absense of small • gauge couplings • High multiplicity of producedparticlesas proportional to a BH entropy • Hard leptons and jets (high transverse momenta), in significant numbers • Approximately thermally determined ratios of species (democratic decay) • Relatively high sphericity for final states

  8. CMS longitudinal view: one fourth

  9. Final state of the SM process vs typical BH decay spectra SM Process BH decay Pictures by Sabine Hossenfelder • Multi-jet and hard leptons events • High spherical • High energy and pT Experimental observables which are sensitive to these features

  10. Individual particle selection and cuts in the analysis • Electrons and photons: for barrel and • for end-cap • Muons: & pT > 20GeV, • Jets: • between any two objects • The multiplicity in the final state: Njet(number of jets) • Under “jets” we assume individual hard objects like jets and also • photons and leptons (e&μ) 11

  11. Scalar sum of the transverse energies of jets Jets, photons and leptons, ET > 50 GeV Missing ET > 50 GeV CMS Detector simulation, the transverse view CMS Detector simulation, the longitudinal view

  12. CMS 3D real event visualisation, N = 9 BH candidate CMS Data, 2011 ST = 2.5 TeV (Run 165567,Event 347495624)

  13. CMS real event visualisation: the transverse view, N = 10 BH candidate CMS Data, 2011 ST = 1.1 TeV (Run 163332, Event 196371106)

  14. Low multiplicity regime (number of objects in FS N=2,3) The CMS analysis 2011, 1.09 fb-1: CMS EXO-11-071

  15. ST for events with N objects in FS The CMS analysis 2011, 1.09 fb-1: CMS EXO-11-071

  16. The CMS analysis 2011, 1.09 fb-1: CMS EXO-11-071 ST for events with N objects in FS

  17. The CMS analysis 2011, 1.09 fb-1: CMS EXO-11-071 ST for events with N objects in FS

  18. BH models without IS energy losses: Mmin is excluded up to 5.1 TeV for MPl up to 3.5 TeV at 95 % CL. (ADD-type scenarios)

  19. String Ball Limits SB(Mmin, Ms, Md) Mmin > 2 Ms gs = 0.4 n = 6 (Md )n+2 =(Ms)n+2/gs Md = Ms/0.79 Tmax =T0= Ms BlackMax v2.01 The CMS 2011, 1.09 fb-1: CMS EXO-11-071 String ball limits from the counting experiments for a set of model parameters (string coupling gs=0.4, fundamental scale Md and string scale Ms) Mmin is excluded from 4.1 to 4.5 TeV at 95 % CL.

  20. Current results, statistics collected about 1.1 fb-1: • Permanently renewable analysis for BH candidates in events with a large final multiplicity and a high sphericity (transverse energy sum for jets) • Background estimation procedure (MC for EW contributions and “data-driven” method for QCD) • For ADD-type models of BH and a number of scenarios (rotating&non-rotating, without IS losses) some limits have been established: 5.1 TeV for a minimal mass of BH and 3.5 TeV for a fundamental scale (be doubly careful when treat a lower region of BH masses near the fundamental scale). • The first direct LHC limits for string ball productionhave been established: minimal mass of SB from 4.1 to 4.5 TeV have been excluded (depending on two scales – fundamental multidimensional and string one). • Important next steps (now and the end of this year, next 2012): • Variety of BH models – energy losses during production stage and different parametrizations for losses,stable remnant, low multiplicity regimes, brane with a tension, etc. (MC study) • Production near the fundamental threshold – breaking down of semiclassical treatment of BH, Quantum BH (MC ? + data) • Update for BH analysis with an integrated luminosity

  21. Backup slides

  22. BH Production in pp collisions at the LHC DL ‘01 • For the LHC energies: • a) Parton-level production • cross section • b) Differential cross section • Hawking temperature • Average decay multiplicity • for Schwarzschild BH n=4 (S. Dimopoulos, G. Landsberg, Phys.Rev.Lett.87:161602, 2001, hep-ph/0106295v1)

  23. Exclusion Limits for ADD (virtual exc.) Dimuons CMS PAS EXO-11-039 Diphotons CMS PAS EXO-11-038 Sergei Shmatov, Searches for Physics Beyond the Standard Model at the CMS Experiment, NPD RAS Conference 2011, Moscow 24

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