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Examples of Science

Examples of Science. Generic fluxes associated with cosmic rays Astrophysics: gamma ray bursts Particle physics: cold dark matter search. Nature’s Particle Accelerators. Electromagnetic Processes: Synchrotron Emission E g a (E e /m e c 2 ) 3 B Inverse Compton Scattering

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Examples of Science

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  1. Examples of Science Generic fluxes associated with cosmic rays Astrophysics: gamma ray bursts Particle physics: cold dark matter search

  2. Nature’s Particle Accelerators • Electromagnetic Processes: • Synchrotron Emission • Eg a (Ee/mec2)3 B • Inverse Compton Scattering • Ef ~ (Ee/mec2)2 Ei • Bremmstrahlung • Eg ~ 0.5 Ee • Hadronic Cascades • p + g ->p± +po +… -> e ± + n + g +… • p + p -> p± +po +… -> e ± + n + g +…

  3. High Energy Gamma-Ray Astrophysics Typical Multiwavelength Spectrum from High Energy g-ray source [ Energy Emitted] [ Photon Energy]

  4. Spinning Neutron Star Fills Nebula with Energetic Electrons • => Synchrotron Radiation and Inverse Compton Scattering

  5. Active Galactic Nuclei • Massive Black Hole Accelerates Jet of Particles to Relativistic Velocities => Synchrotron Emission and Inverse Compton and/or Proton Cascades

  6. Challenge I: Acceleration shock velocity n R (V = e F; b = v/c) B n • = boosted energy from cosmic accelerator

  7. Energy in extra-galactic cosmic rays ~3x1037 erg/s or 1044 erg/yr per (Mpc)3 3x1039 erg/s per galaxy 3x1044 erg/s per active galaxy 2x1052 erg per gamma ray burst 1 TeV = 1.6 erg

  8. brightest known sources match IF equal energy in protons and electrons (photons) • AGN (steady): G~ few requires L>1047 erg/s Few, brightest AGN • GRBs (transient): G~ 300 requires L>1051 erg/s Average Lg~1052 erg/s equal energy in neutrinos?

  9. some definitions • flux F = dN/dE (particles cm-2 s-1) • fluency f = E dN/dE (erg cm-2 s-1) • luminosity L = f x 4pd2 (erg s-1)

  10. PointSources Signal: Background (atmos. n’s): For 10 -- 1000 TeV:

  11. Cosmological sources: Most Powerful Cosmological sources: AGN (Steady) GRBs (~100s transient) • ~1 km2 detector • Same UHE CR “suspects”

  12. Challenge II: Propagation (GZK) • >1020eV proton: lE<100 Mpc • Bright AGN (Radio galaxies)- too far  • GRBs  Does the spectrum support GZK?

  13. [EW 95] Model • Fly’s Eye fit for Galactic heavy (<1019eV): JG~E-3.50 • X-Galactic protons: Generation spectrum (shock acceleration): Generation rate: Redshift evolution ~ SFR

  14. [Bahcall & EW 03] Model vs. Data X-G Model: Ruled out 7s 5s

  15. Conclusions are Robust

  16. CR Conclusions • Yakutsk, Fly’s Eye, HiRes: Consistent with XG protons: + GZK Robust; Consistent with GRB model predictions • AGASA (25% of total exposure): Consistent below 1020eV Excess above 1020eV: 2.2+/-0.8 8 observed New source/ New physics/ 25% energy Local inhomogeneity over-estimate • Stay tuned for Auger (Hybrid) ??

  17. diffuse flux flux = velocity x density flux = c/4p x density, for isotropic flux --> in energy density E dN/dE dE= c/4p x rE E dN/dE = A E -g cm-2 s-1 sr-1 (g = -1)

  18. diffuse background Signal: Background (atmos. n’s): Waxman-Bahcall bound ~ 1km2 detector --> 50 events/yr

  19. n Flux Bound • Observed JCR(>1019eV) • For Sources with tgp < 1: • Strongest know z evolution (QSO, SFR): collect n’s beyond GZK [EW & Bahcall 99, Bahcall & EW 01]

  20. tgp for known sources e’g p+ e+ eg n e- ep

  21. Antares Nemo

  22. Neutrinos from GRB: an example

  23. Gamma-ray Bursts M on ~1 Solar Mass BH Relativistic Outflow G~300 e- acceleration in Collisionless shocks e-Synchrotron MeV g’s Lg~1052erg/s [Meszaros, ARA&A 02]

  24. Gamma Ray Burst • Photons and protons • coexist in internal • shocks • External shocks

  25. Correlations to BATSE Gamma Ray Bursts ? 1969 BATSE: 1991- May 2000 1997

  26. NUMEROLOGY • Lg = 1052 erg/s • R0 = 100 km • Eg = 1 MeV • t = 1-10 msec • = 300 • tH = 1010 years • dE/dt = 4x1044 erg Mpc-3yr-1 • Pdetected = 10-6 En0.8 (in TeV) • spg = 10-28cm2 for p+gn+p • < xp p > = 0.2

  27. GRB1 FRAMES Fireball Frame Observer Frame DR R' R v c g ~ 102 - 103 E = g E' ~ 1 MeV R = g R' d DR = cDt = R0 with R0 = R' (t = 0) observed 1 msec

  28. R0 100 km • cos  = v/c ~ - grb kinematics R v2 __ c2 q g = [1- ]-1/2 v ~ - 102 - 103 q c DR __ c 1 _ c Dt = = (R - Rcosq) v __ c R __ 2c R __ c v2 __ c2 R __ 2c 1 __ g2 ~ - ( 1 - ) (1- ) ~ - = • Dtobs • DEobsg E ~ -

  29. GRB3 Pion (neutrino) production when protons and photons coexist neutrinos pg np+ gamma rays np0 Ep > 1.4 x 104 TeV m2D - m2p _________ 4E'g E'p > ~ _ ~ _ En = 1/4 < xp p> Ep 1/20 Ep 0.7 PeV

  30. GRB4 Fraction of GRB energy converted into pion (neutrino) production DR' ___ lpg ~ _ f p = <x p p> 15% l-1pg = ng spg e g (Lg) synchro/ICompton fireball p n pions (LCR)

  31. GRB2 Photon Density in the Fireball LgDt/g ______ 4pR'2DR' U'g ___ E'g ng = = E'g ___ g R' = g2cDt DR' = gcDt note: for g = 1 (no fireball) optical depth of photons is topt = = R0ngsTh ~ 1015 R0 __ lTh

  32. GRB 5 Neutrino flux from GRB fireballs U ___ E 1 ___ E fn = = (1/2 f tH) c __ 4p c __ 4p dE __ dt ~ _ charged p only LCR Lg Nevents = Psurvived Pdetected fn 20 km -2 yr -1 ~ _

  33. GRB 6 NUMEROLOGY <xp -> p> = 1/5 spg = 10-28cm2 tH = 1010 years dE/dt = 4x1044 erg Mpc-3yr-1 Pdetected = 10-6 En0.8 (in TeV) Lg = 1052 erg/s R0 = 100 km Eg = 1 MeV t = 1-10 msec g = 300

  34. Search for HE n from GRB

  35. Correlations to GRB Background cuts can be loosened considerably  high signal efficiency 88 BATSE bursts in 1997 Combined data give sensitivity ~ prediction!

  36. Marriage of Astronomy and Physics • Astronomy: new window on the Universe! “You can see a lot by looking” • Physics: search for dark matter search for topological defects and cosmological remnants search for monopoles measure the high-energy neutrino cross section (TeV-scale gravity?) cosmic ray physics: 150 atmospheric nus/day array with EeV sensitivity test special and general relativity with new precision

  37. Relic density – simple approach Decoupling occurs when G < H We have

  38. The Lightest Supersymmetric Particle (LSP) Usually the neutralino. If R-parity is conserved, it is stable. The Neutralino – c Gaugino fraction 1. Select MSSM parameters 2. Calculate masses, etc 3. Check accelerator constraints 4. Calculate relic density 5. 0.05 < Wch2 < 0.5 ? 6. Calculate fluxes, rates,... Calculation done with The MSSM – general http://www.physto.se/~edsjo/darksusy/

  39. Wh2 > 1 LEP Wh2 < 0.025 Low sampling The mc-Zg parameter space Gauginos Mixed Higgsinos

  40. WIMP search strategies • Direct detection • Indirect detection:– neutrinos from the Earth/Sun– antiprotons from the galactic halo– positrons from the galactic halo– gamma rays from the galactic halo– gamma rays from external galaxies/halos– synchrotron radiation from the galactic center / galaxy clusters– ...

  41. WIMP + nucleus WIMP + nucleus • Measure the nuclear recoil energy • Suppress backgrounds enough to be sensitive to a signal, or... • Search for an annual modulation due to the Earth’s motion around the Sun Direct detection - general principles

  42. Most likely DAMA point. Excluded at 99.8% CL EdelweissJune 2002

  43. Direct detection – current limits Spin-independent scattering Spin-dependent scattering Direct detection experiments have started exploring the MSSM parameter space!

  44. rc velocity distribution c n interactions Earth sscatt n int. m int. nm Gcapture Gannihilation m Detector Neutralino capture and annihilation Sun interactions hadronization Silk, Olive and Srednicki, ’85Gaisser, Steigman & Tilav, ’86 Freese, ’86; Krauss, Srednicki & Wilczek, ’86Gaisser, Steigman & Tilav, ’86

  45. Indirect detection for cyclists e.g. 104 m2n-telescope searches for 500 GeV WIMP > LHC limit 300 km/s 1.  - flux 500 GeV ________ mz  =rcv = 2.4 x 104 [ ]cm-2s-1 500 GeV ________ mz 0.4 GeV cm-3 = 8 x 10-4 [ ] cm-3 2. Solar cross section M8 __ mN S =ns =s (N)= [1.2x10]57 10-41cm2 GF2 ___ mZ2 MZ2 ___ mH4 (GF mN2)2 ~

  46. N = capture rate = annihilation rate _ c c WW 250 GeV 500 GeV mnm N8 = S= 3 x 1020 s-1 3. Capture rate by the sun 4. Number of muon-neutrinos Nnm = 2 x 0.1 N Leptonic BR~0.1

  47. Nnm ____ 4pd2 5. nm = = 2 x 10-8 cm-2 s-1 1 A.U. 5.5 x 1023 cm-3 6. # events = area x nm x ice x sn m x Rm 104 m2 En ___ GeV • sn m = 10-38 cm2 = 2.5 x 10-36 cm2 ~ _ E ___ GeV • Rm = 5m = 625m (Em 0.5 En) # events = 10 per year

  48. WIMPs in Center of Earth Baikal AMANDA limit – 10 strings only

  49. Limits: m flux from the Earth/Sun Earth Sun

  50. Flux from Earth/Sun and future GENIUS/CRESST limits Earth Sun

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