Caltech Composite Inelastic Dark Matter

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An April 13, 2010 presentation on composite inelastic dark matter

An April 13, 2010 presentation on composite inelastic dark matter

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  • 1. Composite Inelastic Dark Matter Jay Wacker SLAC Caltech April 13, 2010 with P. Schuster, D. Alves, S. Behbahbani, M. Lisanti, A. Hook, E. Izaguirre arXiv: 0903.3945, 0911.1997, 0911.4483, 1003.4729....
  • 2. Dark Matter Discovering its nature is a great open question 80% of the Universe’s mass is unknown What we know: Cold/Massive Suppressed EM & Strong interactions Isn’t strongly self-interacting WIMP Miracle drives a lot of the thinking DM is a thermal relic for 1000 GeV weakly interacting particle Most DM model building links weak scale/hierarchy problem
  • 3. Status of Dark Matter Not your grandfather’s DM Candidate DAMA PAMELA ATIC FERMI Electrons WMAP Haze INTEGRAL CoGeNT Hints at non-trivial mass scales & interactions
  • 4. Secluded Sectors “Hidden Valleys” Standard Secluded Model Weak Connection Sector L = φsecluded Oportal Oportal = FY , |h|2, hL , jB−L , µν µ λY , etc
  • 5. Secluded Sectors “Hidden Valleys” High Energy/Intensity Standard Secluded Model Weak Connection Sector Slow decays back to SM L = φsecluded Oportal Oportal = FY , |h|2, hL , jB−L , µν µ λY , etc
  • 6. Secluded Sectors “Hidden Valleys” High Energy/Intensity Standard Secluded Model Weak Connection Sector Slow decays back to SM L = φsecluded Oportal Oportal = FY , |h|2, hL , jB−L , µν µ λY , etc Ubiquitous in Top-Down Models Hard part is getting rid of additional gauge groups & matter Dark Matter might be a secluded sector
  • 7. Dark Matter Model Building Occam’s Razor vs. Principle of Plentitude “Plurality should not be posited “No possibilities which remain eternally without necessity” possible will go unrealized” When searching in the dark, Occam’s Razor can lead to blind spots!
  • 8. Dark Matter Model Building Occam’s Razor vs. Principle of Plentitude “Plurality should not be posited “No possibilities which remain eternally without necessity” possible will go unrealized” When searching in the dark, Occam’s Razor can lead to blind spots! Minimality may not be best guide to Dark Matter’s existence Why should 20% of the mass, have all the fun? Gauge theories appear in SM & many BSM constructions Models illustrate new mechanisms and new experiments
  • 9. Plan of Talk DAMA & Inelastic Dark Matter Composite dark matter models Experimental Prospects Discussion
  • 10. Direct Detection χ N χ N Dark matter scatters off nuclei in detectors Measure nuclear recoil spectrum [Counts/kg day/keV] ￿ ￿ dR ρDM dσ = v dER mDM mN dER average over initial DM velocities Multiply by exposure [kg day]
  • 11. Spectrum of Recoils Minimum DM velocity to scatter cause ER recoil ￿ mN E R vmin = 2µ2 Boltzmann Distribution ￿ vesc dR dσ 3 −v 2 /v0 2 −ER /E0 dER ∝ d v dER ve ∼e vmin Average over initial DM velocities in the galactic halo 2µ2 v0 2 Falling spectrum ∼ 25 keV E0 = mN Push to lower energy thresholds
  • 12. DAMA Residuals NaI Experiment running for 13 years Time (day) Galactic Dark Matter 2-5 keV Annual modulationkg inton"yr) WIMP signal Residuals (cpd/kg/keV) DAMA/LIBRA ! 250 (0.87 ￿⊙ v Φdm = ndm v summer winter ￿E v ￿E v Amod = RSum − RWin Modulation amplitude ~2.5% for v ≤ vesc + |vE − v⊙ | ￿ ￿ v ≤ vesc + |vE + v⊙ | ￿ ￿ elastic scattering Time (day) 2-6 keV Residuals (cpd/kg/keV) DAMA/LIBRA =250 kg (0.87 (0.87 ton yr) DAMA/LIBRA ! 250kg ton"yr) Time (day)
  • 13. Current Limits -5 10 http://dmtools.brown.edu/ Cross-section [pb] (normalised to nucleon) DAMA Gaitskell,Mandic,Filippini 2 Excluded LIN ZEP by a factor -6 RE SS T of 30 10 C ZE PL IN 3 -5 XE 10 -7 S http://dmtools.brown.edu/ DM [pb] (normalised to nucleon) 10 NO C Gaitskell,Mandic,Filippini N -6 10 -8 090913122401 spin-independent 10 1 2 3 10 10 10 WIMP Mass [GeV/c2] -7 10
  • 14. Inelastic Dark Matter Dark matter has two nearly degenerate states δm ∼ (100 keV) Tucker-Smith and Weiner, hep-ph/0101138. Scattering off SM transitions between states χ2 q χ1 q Higher threshold velocity necessary to scatter, Higher typical recoil energies ￿ ￿ 1 mN ER vmin = √ + δm 2mN ER µ Lighter nuclei, higher threshold
  • 15. Inelastic Dark Matter Threshold behavior Rate Recoil Energy (keV) 3 Consequences (1) Scatters off of heavier nuclei -- CDMS ineffective (2) Large recoil energy -- ZEP3 & Xe10 didn’t initialy look (3) Large modulation fraction -- absolute signal is smaller 3 Coincidences XENON10, CRESST II, ZEPLIN2 all had events
  • 16. Larger Modulation Fraction Smaller rate One reason for apparent tension 3.5 3.0 Summer scattering v 2 f (v)/10−4 2.5 2.0 Winter scattering 1.5 v0 1.0 Boost f(v) into Earth’s frame 0.5 vesc 0.0 0 100 200 300 400 500 600 0 100 200 300 400 500 600 1.2 velocity 1.0 elastic 0.8 2.5% modulation # of Events 0.6 0.4 0.2 inelastic 100% modulation 0.0 0.2 0.4 0.6 0.8 1.0 June 2 Dec 2 June 2 Factor of 40 difference in translating modulated to unmodulated rate!
  • 17. Recent Experiments Inelastic DM has a lot in common with Mark Twain “The report of my death was an exaggeration” XENON100 reported 0 events ... but ran in late Oct through early Nov. CRESST reported exclusion ... but had 40 keV upper threshold ... and won’t release their raw results CoGeNT reported anomalous low energy events ... points to low mass dark matter (not iDM)
  • 18. Inelastic Dark Matter A new number to explain: δm ∼ 10−6 m Sign of dark sector dynamics? First of many splittings New interactions to discover Changes which questions are interesting Will be confirmed/refuted in 2010! XENON100
  • 19. Hyperfine Splittings Magnetic moment splitting Can give very small energy differences HHF ∼ µ1 · µ2 δ (r) ￿ ￿ 3 g ￿ µ￿ S ￿ m Occurs in all bound state systems Fermions + Gauge interactions
  • 20. Hyperfine Splittings Weakly Coupled: Hydrogen s=1 m2 ∆E ∼ α 4 mp e 1s s=0 1 µeV Strongly Coupled: Heavy Flavor Mesons (B, B*) Λ2 s=1 1s QCD ∆E ∼ s=0 45 MeV mb
  • 21. Open Questions Can engineer systems with 100 keV mass splittings Coupling to Standard Model? Inelastic transitions dominate over elastic? Cosmology constraints? How will we know?
  • 22. Plan of Talk DAMA & Inelastic Dark Matter Composite dark matter models Experimental Prospects Discussion
  • 23. Anatomy of Composite Inelastic Dark Matter Simple Setup, Rich Dynamics dark quarks kinetic mixing qH ￿ Fd µν FY µν SU(N) U(1)d SM qL Start with left and move right
  • 24. Composite Inelastic Dark Matter Alves, Behbahani, Schuster, JW, 0903.3945. 1 Ldark = − Tr G2 + q iD q + m¯q ¯￿ q 2 µν New SU(Nc) gauge sector confines at scale Λd ￿ ￿ 2π Λdark ∼ exp − b0 αdark Two dark quarks qH qL mH ￿ Λdark , mL No flavor changing effects: stabilizes DM
  • 25. Cosmology of CiDM Alves, Behbahani, Schuster, JW: 0903.3945 + 1003.4729 A primordial cosmological dark quark asymmetry (nH − nH ) = −(nL − nL ) ￿= 0 ¯ ¯ More heavy quarks than antiquarks More light antiquarks than quarks Given up Wimp Miracle for asymmetric DM Driven off of SM’s baryon asymmetry? nDM 5 GeV ￿ nbaryon mDM
  • 26. Cosmology of CiDM Alves, Behbahani, Schuster, JW: 0903.3945 + 1003.4729 A primordial cosmological dark quark asymmetry (nH − nH ) = −(nL − nL ) ￿= 0 ¯ ¯ More heavy quarks than antiquarks More light antiquarks than quarks Given up Wimp Miracle for asymmetric DM Driven off of SM’s baryon asymmetry? nDM 5 GeV ￿ nbaryon mDM ¯ When T ￿ Λd , dark matter is in qH qL bound state qH ¯ qL
  • 27. States of CiDM Alves, Behbahani, Schuster, JW, 1003.4729. Heavy quarks can bind together 2 EBind ∼ αdark mH Heavy Quarks 0 1 2 3 4 Mesons Baryons More deeply bound Dark Matter Synthesis occurs
  • 28. (1) number density of dark matter is the πd state and there are other com Dark Matter Synthesis of the dark matter to discover. A chainIV:, Arrested The completeexothermic a few percent in the form Region reaction, increasingly densities, with unsynthesized compon and πd share comparable mass synthesized and pions, πd and π1 → 2 + 0 step of Q = 2EB − mlightπd → πd π 1 + d . The first (2) (3) (1) (1) (2) the synthesis chain, πd bottleneck much like deuterium formation slows BBN in the Standard M 2+1→3+0 Q = 10E has mlight − only occurs for a brief period, but once the πd B formed, it processe (2) into BH . 2 + 2 → 4 + 0 Q = 32EB Region V: Inhibited The3 + 1 Q = 8EB 2 + 2 → first step of the synthesis chain is strongly supre (1) the CiDM 3 + 1 → 4 is dominatedQ = d24E composition + 0 by π . Region V is the cosmolo B in [7]. The heavy baryon component mostly arises through the primor First reaction is potential bottleneck formation described in Sec. 3.2. A quantitative description lightest dark hadron one of these regions is sum Depends on mass of of the abundances in each in Table 3. !m=95keV Region ρπ(1) /ρDM ρπ(2) /ρDM ρπ(3) /ρDM ρBH /ρDM d d d III mH (GeV) 10−4 − 0.1% 10−4 − 0.2% 10−3 − 0.9% ￿d (MeV) I > 99% II 0.1% − 4% 0.2% − 5% 0.9% − 11% 80% − 99% IV III 4% − 57% 5% − 24% 11% − 17% 9% − 80% II IV 57% − 99% < 5% < 5% 1% − 30% V V > 99% < 10−5 < 10−5 < 1% I Table 3: The relations on the fractional mass densities that define the region mlight /￿d matter synthesis in Fig. 1.
  • 29. Splitting of Ground State Mass difference in meson states arises from hyperfine splitting Coulombic limit mH mL qH α4 m2 ¯ δm ∼ d L Energy Λd qL mH For U(1): Atomic Dark Matter D. E. Kaplan, et al (2009) (Susy version in progress ) spin 0 spin 1 dark pion dark rho πd ρd
  • 30. Splitting of Ground State Mass difference in meson states arises from hyperfine splitting Coulombic limit mH mL qH α4 m2 ¯ δm ∼ d L Energy Λd qL mH mL For U(1): Atomic Dark Matter D. E. Kaplan, et al (2009) (Susy version in progress ) spin 0 spin 1 Confined qH Λ2 d dark pion dark rho ¯ qL δm ∼ πd ρd mH
  • 31. Spin Temperature Need to explain why iDM is in ground state Self interaction keeps DM in equilibrium ρ d ρ d → πd πd Solves de-excitation problem nρd = exp(−δm/Tspin ) n πd Kinetically decouple late, smaller spin temperature Tspin < 10 keV ∼ Still Satisfy Self-Interaction Limits σ < −2 cm2 1 bn m ∼ 10 g ∼ 100 GeV
  • 32. Dark Matter Couplings Couples to a secluded U(1) Axial-Vector Coupling µ Jd = qH γ µ γ 5 qH − qL γ µ γ 5 qL ¯ ¯ Forbids quark masses until U(1)d Higgsed How does the U(1) couple to mesons? Dark Matter Scattering ¯ qH qL ρµ d elastic inelastic mass πd πd→πd πd→ρd spin 0 meson spin 1 meson πd → −πd ρdµ → (−1)µ ρdµ
  • 33. Axial Coupling to Mesons Elastic πd→πd Forbidden † πd ∂µ πd Aµ Parity d 1 † µν πd ∂µ πd ∂ν Fd Λ2 d 1 † Vanishes ˜ µν 2 πd ∂µ πd ∂ν Fd Λd
  • 34. Axial Coupling to Mesons Elastic Inelastic πd→πd πd→ρd Suppressed Velocity Forbidden † πd ∂µ πd Aµ mπd † πd ρ µ d µ Ad Parity d 1 † µν πd ∂µ πd ∂ν Fd Λ2 d Dominant 1 † 1 † µ ν Vanishes ˜ µν 2 πd ∂µ πd ∂ν Fd Λd Λd πd ∂ ρd Fdµν Near purely Inelastic
  • 35. Coupling to Standard Model Kinetically mix U(1)d with U(1)Y U (1)d U (1)Y DM SM ψgut 1 µν 1 µν ￿ µν 1 LU(1) = − Fd Fdµν − B Bµν − Fd Bµν → − F 4 4 2 4
  • 36. Coupling to Standard Model Kinetically mix U(1)d with U(1)Y U (1)d U (1)Y DM SM ψgut 1 µν 1 µν ￿ µν 1 LU(1) = − Fd Fdµν − B Bµν − Fd Bµν → − F 4 4 2 4 Higgs U(1)d near the electroweak scale LHiggs = |Dµ φd |2 − V (φd ) → m2 A2 d d md = 2gd vφ
  • 37. Coupling to Standard Model Kinetically mix U(1)d with U(1)Y U (1)d U (1)Y DM SM ψgut 1 µν 1 µν ￿ µν 1 LU(1) = − Fd Fdµν − B Bµν − Fd Bµν → − F 4 4 2 4 Higgs U(1)d near the electroweak scale LHiggs = |Dµ φd |2 − V (φd ) → m2 A2 d d md = 2gd vφ Gives mass to fermions LYuk = +c yL q L q L φ c † yH q H qH φ mf = yf vφ
  • 38. Coupling to Standard Model Holdom 1985 Kinetically mix U(1)d with U(1)Y U (1)d U (1)Y DM SM ψgut After EWSB: L = −Fd − FEM − ￿Fd FEM + m2 A2 + JEM AEM + Jd Ad 2 2 A d kinetic mixing redefine SM photon AEM → AEM − ￿Ad
  • 39. Coupling to Standard Model Holdom 1985 Kinetically mix U(1)d with U(1)Y U (1)d U (1)Y DM SM ψgut After EWSB: L = −Fd − FEM − ￿Fd FEM + m2 A2 + JEM AEM + Jd Ad 2 2 A d kinetic mixing redefine SM photon AEM → AEM − ￿Ad L = −Fd − FEM + m2 A2 + JEM (AEM − ￿Ad ) + Jd Ad 2 2 A d µ Lint ∝ ￿Jem Adµ SM is milli-charged under dark U(1), DM is neutral under EM
  • 40. Current Limits on ε 10-1 (g − 2)µ Υ decays 10-2 ￿ 10-3 E774 M D Ci 10-4 E141 10-5 E137 10 MeV 100 MeV 1 GeV 10 GeV 100 GeV mAd Model independent limits not known for 1 GeV to 200 GeV Precision EW + High energy Bounds 2 ￿ 2 2 ￿ (w/ A. Hook & E. Izaguirre) e ￿ q α(q ) = 2 1+ 2 4π q + mAd
  • 41. CP-Violation ˜ Θ term in dark QCD sector Lcpv = Θd TrGd Gd Not necessarily small Leads to mixing between states of different parity e.g. πd ↔ a0d In limit mL → 0 chiral rotation removes Θ term Parity violating mixing sin θp Scalar states neutral under U(1)d sin θp † µν Leads to πd ∂µ πd ∂ν Fd Λd 2
  • 42. ansition Charge Radius Scattering parity! gd µνσρ sin θp † † µν int = ￿ πd ∂µ πd ∂ν Fd Fdark µν2 ρd σ ∂ρ πd Λd Λdark Neutral composite states with charged constituents velocity suppressed −6 smaller (ER ) Fdm Form-factor suppression from 10 πd sition interaction with background field q gd µν † Lint = 2 Lcr∂µFdm (ER )¯ieAdν πd F π ∂ = dark q d ￿ q Λdark γd Fdm (0) = 0 + rc ER 2 q MDMπ200 GeV, im 6 elastic Charge Radius scattering M 200 GeV, M 1 GeV 0.030 DM A d 125 keV, MA 1 GeV Count Rate arbitraty units 0.030 0.025 Charged Elastic Scattering Charged Radius Elastic Scattering elastic 0.025 w cpd kg keV 0.020 0.020 Rate 0.015 charge-radius Charge-radius scattering difficult to 0.015 0.010 distinguish from inelastic scattering 0.010 0.005 0.005 0.000 0.000 20 40 60 80 100 ER recoil E 0.005 1 2 3 4 5 6 7 8 ER KeVee ER KeVee
  • 43. Plan of Talk DAMA & Inelastic Dark Matter Composite dark matter models Experimental Prospects Discussion
  • 44. Standard Halo Model N-body simulations indicate that density falls off more steeply at larger radii 3.5 3 3.0 isothermal, isotropic, & Gaussian ￿ ￿ v 2 f (v)/10−4 2.5 2 2 f (v) ∝ e−(v/v0 ) − e−(vesc /v0 ) Θ(vesc − v) 2 2.0 v0 1.5 1 1.0 0.5 vesc 0 0.0 0 100 200 300 400 500 600 0 100 200 300 400 500 600 velocity
  • 45. Modified SHM Will use modified ansatz ￿ 2α 2α ￿ f (v) ∝ e−(v/v0 ) − e−(vesc /v0 ) Θ(vesc − v) 3.5 α parameterizes variation in the 3 3.0 α=1.1 tail of the distribution ) v 2 f (v)/10−4 2.5 α=0.8 captures qualitative behavior of 2 2.0 v0 ) N-body simulations 1.5 1 1.0 0.5 600 vesc 0 0.0 0 100 200 300 400 500 600 0 100 200 300 400 500 600 velocity
  • 46. Marginalizing over Uncertainties How do current experiments constrain parameters? Usually astrophysical parameters are benchmarked 0.8 ≤ α ≤ 1.25 particle physics astrophysics 200 ≤ v0 ≤ 300 mπd , δm, σ v0 , vesc , α 500 ≤ vesc ≤ 600 ￿ ￿2 ￿ pred Xi obs − Xi χ (m, δ, σ, v0 , ve , α) = 2 σi Minimize χ2 over 6 parameters using results from direct detection experiments Fit to DAMA recoil spectrum No experiment rules out point at 95% CL
  • 47. Parameter Space θp = 0, 4%, 6%, 8% Best fit mπd ∼ 70 GeV δm ∼ 95 keV Slow halos v0 ∼ 200 km/s α > 1.0 ∼
  • 48. Global Fit gd2 2 gd gd mπd mAd ￿ gd vφ ￿ 4 → 4 yH q mAd 0.010 0.005 0.001 5 ￿ 10￿4 DAMA Regions Ε 1 ￿ 10￿4 5 ￿ 10￿5 θp = 0, 6%, 8% 1 ￿ 10￿5 Dark Photon Mass ￿GeV￿ 0.01 0.1 1 10 100
  • 49. DAMA Best fits Modulation Amplitude 0.03 θp =c0%, 8% el/cin=0 cel/cin=0.15 counts￿kg￿day￿keVee 0.02 0.01 0.00 Recoil Energy ￿keVee￿ 0 2 4 6 8 Difficult to distinguish from DAMA mixed elastic-inelastic scattering
  • 50. Xenon100 100 kg Liquid Xe detectors (upgrade for Xenon10) Will see a large number of events DAMA rate: 0.02/kg d/keV Nevents > 0.5 Nevents > 40 0.25 0.25 0.20 0.20 Frequency Frequency 0.15 0.15 0.10 0.10 0.05 0.05 0.00 0.00 0 20 40 60 80 100 120 0 20 40 60 80 100 120 ￿ Events Observed ￿ Events Observed (1000 kg-day exposure ~ 1 month!) Tail down to small < 5 events
  • 51. Xenon100 Recoil Spectrum 5.00 1000 kg· day : summer 1.00 : winter 0.50 counts￿keV 0.10 0.05 Recoil Energy ￿keV￿ 0 20 40 60 80 Elastic subcomponent apparent but distorts spectrum, inelastic kinematics get washed out Directional detection experiments key
  • 52. Plan of Talk DAMA & Inelastic Dark Matter Composite dark matter models Experimental Prospects Discussion
  • 53. Future Work Susy: New Hierarchy Problem SM might be mediator of DM SSB Nearly Susy bound states Possible DM forming MACHOS Discovering other components Light Baryons Heavy Baryons & Multicore Mesons Generating Asymmetry Decays & Annihilations Cosmic Ray Signals Collider Signatures Lepton Jets
  • 54. Collider Signatures + − + Light mesons ωD ηD − √ ωD s ΛD 23-4/"5-&)")'& 0/-(*5506")'!-7')& !"#$%&'()*# &+*,'#-. qD +"!#*/01")0*/ √ s ΛD p e− p+ e #*89+5:-&;+'#0("5- '<'/) ¯ qD γ mA ΛD ωD ωD Lepton Jets =**&)'!-;#*!8()&- + − ωD #'(*05-*>>-;+*)*/ − ηD + − + ωD
  • 55. Signal Simulation (w/ A. Haas & Y. Gershtein) Need Hadron Spectrum + Decays Dark Showering Sherpa & Herwig Dark Hadronization Sherpa & Herwig Cascading to SM
  • 56. DarkSpecGen (w/ S. Behbehani) An interface to produce semi-realistic hadronic final spectra and decay tables and interface to Sherpa & Herwig Gauge SU(N), Sp(2N), SO(N) Partons Reps (Fund, Adj) Nf, Masses, Spins Strong Decays Weak Decays Flavor/CP SM Neutral Portals
  • 57. Conclusions Inelastic DM is an elegant explanation for DAMA vs the Rest of the World New scale to explain: New Dynamics Discovery or Refutation Imminent Within the year iDM sensitive to halo: Need to go beyond SHM New measurements are important Directional Detection Finding DM subcomponents Measuring Halo properties