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Alexandre Kisselev Institute for High Energy Physics Protvino, Russia

Extra dimensions and high energy cosmic neutrinos. Alexandre Kisselev Institute for High Energy Physics Protvino, Russia. Xth International School-Seminar “The Actual Problems o f Microworld Physics ” Belarus, Gomel, July 23 , 200 9. Outlook.

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Alexandre Kisselev Institute for High Energy Physics Protvino, Russia

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  1. Extra dimensions and high energy cosmic neutrinos Alexandre Kisselev Institute for High Energy Physics Protvino, Russia Xth International School-Seminar “The Actual Problems of Microworld Physics ” Belarus, Gomel, July 23, 2009

  2. Outlook Spectrum of high energy cosmic rays (CRs)  Diffuse fluxes of cosmic neutrinos  Space-time with extra dimensions (EDs)  Neutrino-nucleon interactions in models with EDs  Neutrino telescopes  Quasi-horizontal air showers at Auger Observatory  Conclusions 

  3. CR spectrum E < 31014 eV – energy region of atmospheric neutrinos Energy scale: GeV – TeV – PeV – EeV – ZeV

  4. GZK - cutoffof CR spectrum (Greisen, Zatsepin, Kuzmin, 1967) Attenuation length for proton scattering on cosmic microwave background (CMB)

  5. Data from AGASA andHiRes AGASA: number of events with E > EGZK HiRes: observation of GZK-cutoff

  6. Data from Auger (Pierre Auger Coll., 2008) Extrapolation of spectrum E-2.69 Expected number of events with E > 100 EeV: 35 ± 1 Number of observed events:1 GZK -cutoff (6)

  7. Diffuse fluxes of cosmic neutrinos “Guaranteed”GZK (cosmogenic)flux  Flux depends significantly on composition of primary particles (proton-heavy nuclei) Cosmic “accelerators’’: active galactic nuclei (AGN), gamma-ray bursts (GRB), …  Flux is sensitive to energy boundary between galactic and extragalactic parts of CR spectrum

  8. Active galactic nucleus (AGN)

  9. Flavor ratio (near neutrino source) After neutrino oscillation (near detector) Bound on diffuse neutrino flux: (all flavors, 1013eV < E < 1020eV) (Waxman & Bahcall, 1999)

  10. Top-down (TD) models (decays of super-massive dark matter, topological defects, etc.)  Models are motivated by AGASA data Domination of photons in CR’s composition is predicted TD models are strongly disfavored by recent data on gamma ray flux Photon fractionin CR spectrum: < 3.8 %, E > 2 EeV < 11.7%, E > 10 EeV (Pierre Auger Coll., 2008) < 1 %, E > 2 EeV (Yakutsk Coll., 2009)

  11. Detection of signals from cosmic neutrinoswill allow: to discover CR point sources and define their position in the Universe  to understand mechanisms of CR acceleration  to define energy boundary between galactic and extragalactic parts of CR spectrum  to measure cosmic neutrino flux, flavor ratio,andneutrino-nucleon cross section N  SM: Nis small and rises slowly with energy significant (dominating) contributionfrom “new physics” is expected at high (ultra-high) energies

  12. Extra dimensions with flat metric (ADD-model) (Arkani-Hamed et al., Antoniadis, 1998) n = number of ED’s MPl - Planck mass MD- D-dimensional gravity scale (D=4+n) R – radius of EDs

  13. Masses of Kaluza-Klein (KK) excitations: Interaction of gravitons with SM fields: Graviton life time: Spectrum – stable spin-2 particles Main signature – “missing mass”

  14. One extra dimension with warped metric (RS-model) (Randall& Sundrum, 1999) AdS5 - space-time: r – radius of ED (- r  y   r)  – curvature parameter Masses of KK-gravitons: xi – rootsof Bessel functionJ1(x)

  15. Gravity TeV brane Planck brane SM y = 0 y =  r

  16. Interaction Lagrangian: Small curvature: (Giudiche et al., A.K. & Petrov, 2005) Spectrum: light KK resonances with mass splitting m   StandardRS scenario: heavy KK resonances (m1~1TeV)

  17. Lower bounds on gravity scale MD “Large”extra dimensions (D = 4+n) Production of gravitons, for instance: (Landsberg, 2008)  One extra dimension with small curvature (n=1) M5 > 1.7 TeV (DELPHI Coll., 2006) M5 > 1.5 TeV (A.K., 2008) HERA: MS > 0.9 TeV (A. Geiser, talk at this School)

  18. Scattering at trans-planckian energies (Giudice et al., 2002; A.K. & Petrov, 2005 ) eikonal approximation Born amplitude is a sum of reggeized gravitons (gravi-Reggeons) with trajectories: (trajectories are characterized by KK-number n)    n AB = n i i

  19. Scattering of cosmic neutrinos off nucleons RS model with small curvature ( = 100 MeV) M5= 3TeV 5 TeV 7 TeV SM (A.K., 2008) MD = 2TeV ADDmodel (n=5) solid line: thin brane dashed line: brane with tension ( 1/TeV) SM Sessolo & McKay, 2008)

  20. Production of microscopic black holes by cosmic neutrinos (D > 4) (Argyres et al., 1998; Banks & Fisher, 1999, Emparan et al., 2000) (Nbh) forn=1,2,…7 Schwarzschild radius of black hole with mass Mbh=s MD = 1 TeV MD = 1 TeV SM Life time< 10-25сек (MD > 1 TeV, Mbh < 10 TeV) solid lines: Mbh(min) = MD dashed lines: Mbh(min)= 3MD LHC: bh= 15 nb  1 pb, MD = 15 TeV becomes ~ twice small, whennvaries from1to7 (14 TeV  E = 108 GeV)

  21. Neutrino telescope IceCube (to be completedin 2011) AMANDA (all flavors): IceCube ( ,one year of operation): IceCube 80  strings 4800 modules  IceTop 16 tanks 32  modules Optimal energies : 10 TeV – 10 PeV

  22. Baikal (NT200) NT200 (2006),all flavors: Veff = 0.2 mt, 10 TeV NT200+ (3 year of operation): Veff =10 mt, 10 PeV Gigatone detector (a project): Veff = 0.5-1.0 km3, > 100 TeV

  23. Neutrino telescopes (Mediterranean Sea) ANTARES (Toulon) NEMO (Capo Passero) KM3NeT (V = 1 km3) NESTOR (Pylos) Optimal sensitivity - at energies E > 10 TeVfor the process:

  24. Detection of radio emission at the South Pole (ANITA) Acoustic and radio signals from electromagnetic cascades (Askaryan,1957, 1961) Coherent radio emission exceeds (dominatesover) optical emission at E> 10 PeV (1 EeV) (since it rises~E2) 1018.5 eV < E < 1023 eV

  25. Pierre Auger Observatory Hybriddetector: 1600 water Cherenkov tanks arranged on area of 3000 km2  24 fluorescence telescopes located at four sites E > 1018 eV

  26. Registration of quasi-horizontal air showers induced by cosmic neutrinos (Berezinsky, Zatsepin, Smirnov, 1969/75) For inclined showers produced in upper part of atmosphere: electromagnetic part of shower is absorbed before reaching detector E >1019 eV: muon component cutoff  probability of proton-induced deeply penetrating shower is < 10-4

  27. Event rate of air showers effective detector area neutrino flux shower energy detection efficiency cross section neutrino attenuation factor y – inelasticity (SM: y = 0.20.24)

  28.  Extrapolation of SM cross sections (Gandhi et al., 1998)  Cross sections beyond SM (Anchordoqui et al., 2006) z >70 Ratio of inclined air showers to showers initiated by Earth-skimming -neutrinos

  29. Expected number of neutrino induced quasi-horizontal (z >75) air showers (RSscenario, 1 year of operation) Expected number of events with black hole production at Pierre Auger detector (ADD scenario, 5 year of operation)

  30. Experimental upper limits on diffuse neutrino flux (converted to a single flavor) Bound on -neutrino flux(Auger Coll., 2008)

  31. Conclusions We have: Cosmic neutrinos are not yet observed  Auger upper limit on diffuse neutrino flux  becomes rather close to “guaranteed” GZK-neutrino flux  We expect: Present and future telescopes will be able to detect signals from high energy cosmic neutrinos in a few years  Detection of these signals  nice possibility of searching for ED effects (physics beyond SM, in general)  Simultaneous registration of inclined showers and Earth-skimming neutrinos allows us toestimate both  and N   If no such events are observed limits onmulti-dimensional gravity scalecomparable with reach limits of the LHC

  32. Пусть мы откроем новые явленья. Но я молю, чтоб эти небеса , По брегам рек могучие дубравы, Речная гладь, некошеные травы, Клин журавлей, алмазная роса Не перешли в другие измеренья! (А.К.)

  33. Additionalslides

  34. Deviation of charged particle in extragalactic magnetic fields

  35. RS model with the small curvature is not similar to a model with one large ED of the size For instance, can be realized only for dis the number of ED’s solar distance strongly limited by astrophysical bounds

  36. Background RS metric (Randall & Sundrum, 1999) Four-dimensional gravitational in the RS model (Boos et al., 2002) Expression is not covariant: indices are raised with the Minkowski tensor while the metric is

  37. Neutrino telescopeANTARES 350 m 450 m 100 m 12 lines 3x25 PM -2500m  60 m

  38. Radio signals from surface of the Moon (detector GLUE)

  39. Antarctic ice=detector of GZK-neutrinos RICE -Radio ice Cherenkov experiment (South Pole) ANITA - Antarctic Impulsive Transient Antenna (Antarctica) IceCube (+IceTop) AURA–Askaryan Under ice Radio Array (South Pole) SPATS–South Pole Acoustic Test System IceRay

  40. Hypothesis E-2n spectrum nm→ m only MC energy Atm. n Amanda 1y Antares 1y WB limit Icecube KM3NeT 1y

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