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Yue Zhao TDLI & SJTU

Boosted Dark Matter Signatures at Neutrino Experiments. Yue Zhao TDLI & SJTU MCTP, University of Michigan NuFact2017, WG5. Outline:. DM review Unconventional DM Models Overview on detecting boosted DM and DM IND

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Yue Zhao TDLI & SJTU

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  1. Boosted Dark Matter Signatures at Neutrino Experiments Yue Zhao TDLI & SJTU MCTP, University of Michigan NuFact2017, WG5

  2. Outline: DM review Unconventional DM Models Overviewon detecting boosted DM and DM IND A review on related works

  3. Dark Matter Overview: • Bullet Cluster (Deep Chandra) Why do we need DM? • Galaxy rotation curve (Wikipedia) • The CMB Anisotropy Power Spectrum (WMAP year 5 data)

  4. Dark Matter Overview: How much do we have? We only know DM through its gravitational interaction! We only understand 5% of the Universe! (Wikipedia)

  5. Dark Matter Overview: Some basic facts we roughly know so far: 8.5 kpc Local DM energy density: Local DM velocity:

  6. Conventional channels: LUX ~ O(ton) WIMP: Relic abundance & EW scale New Physics Decades of efforts focused on WIMPs! So far, no solid evidence on discovery!

  7. Detect BDM: Boosted DM is generic! DM particle in the final state is moderately boosted. J. Berger, Y. Cui, Y.Z. JCAP, (2015) The Sun as the source, DM-p/n scattering. Junwu Huang , Y.Z. JHEP (2014)

  8. Boosted DM detection Channels: Boosted DM detection: DM particle is energetic enough to knock a nucleon out! v ~ O(1) c p/n Looking for proton/neutron knocked out of a nucleus. Similar to neutrino neutral current interaction! DM-nucleon scattering cross section can be less constrained! Large Volume Neutrino Experiments Super-K ~ 50K ton! DUNE ~ 68K ton!

  9. Boosted DM detection Channels: Boosted DM detection: DM particle is energetic enough to knock a nucleon out! v ~ O(1) c electron Looking for electron knocked out of an atom. Similar to neutrino neutral current interaction! DM-nucleon scattering cross section can be less constrained! Large Volume Neutrino Experiments Super-K ~ 50K ton! DUNE ~ 68K ton!

  10. DM IND detection strategies: (not covered here) DM Induced Nucleon Decay: DM as initial state is invisible in nucleon decay experiments. The signature can be very similar to a nucleon decay process SM objects e.g. mesons Looking for proton/neutron decay events. But kinematics is very different! Similar studies in Darkogenesis model, J. Shelton, et. al. PRD (2010) Hylogenesis model, H. Davoudiasl, et. al. PRL (2010) Large Volume Nucleon Decay Experiments Super-K ~ 50K ton! DUNE ~ 68K ton!

  11. Boosted DM flux: (Extra)Galactic flux Flux is determined by interaction rateand distance. nearby sources concentrated volume of DM 8.5 kpc Galaxy center: Extragalactic flux is also a choice.

  12. Boosted DM flux: Sun (Jupiter/Earth) Flux is determined by interaction rateand distance. nearby sources concentrated volume of DM The other choice is the Sun! (large, dense and nearby) DM can be captured by the Sun if it loses enough energy after scattering. Equilibrium after accumulation: Capturing v.s. Annihilation.

  13. Boosted DM flux: Sun (Jupiter/Earth) DM self-interaction can enhance the capture rate. self-interaction induced evaporation rate self-interaction induced capture rate Kyoungchul Kong, Gopolang Mohlabeng, Jong-Chul Park Phys.Lett. B743 (2015) 256-266

  14. Boosted DM flux: Relevant processes: ,e ,e DM-nucleon scattering cross section is the most important input for this chain! very few inputs model independent

  15. Neutrino experiments for boosted DM: Multiple choices: • Super/Hyper-Kamiokande (50~1000K ton) Cherenkov ring detector Limited energy range not too low: proton momentum > 1.07 GeV (no signal) not too high: proton momentum < 2 GeV (inelastic scattering, messy final states) • MicroBooNE/DUNE (0.17~68K ton) Liquid Argon Time Projection Chambers (LArTPCs) Lower energy threshold Better control/identification on hadronic activity Better angular resolution • IceCube/PINGU/MICA (~1M ton) Photomultiplier Tube Energy threshold is 100 GeV But may be lowered in the future.

  16. A Quick Summary: Channels: • Nucleon • Generically larger cross section • Some scenarios can be very model independent • Electron • Signal is clean and easy to model Source: • (Extra-) Galactic flux • Solar flux (Earth/Jupiter) Detector: • Super-K/Hyper-K • DUNE • IceCube (PINGU/MICA)

  17. Nucleon Channel: Super/Hyper-K Joshua Berger, Yanou Cui , Y.Z. JCAP (2015) SK I,II: 2287.8 days Already exceed the limits from DM DD! Particularly useful in low mass regime and operators with velocity suppression! SK I-IV: 4438.2 days HK: 4438.2 days, angular infor.

  18. Nucleon Channel: DUNE Lowering energy threshold helps a lot! It is promising to carry out this search using LArTPCs. May also be useful to study scatterings through a light mediator.

  19. Nucleon Channel: DUNE Signals can have more structures if more assumptions are imposed. Doojin Kim, Jong-Chul Park, Seodong Shin arXiv:1612.06867 [hep-ph]

  20. Nucleon Channel: IceCube Joachim Kopp, Jia Liu, Xiao-Ping Wang, JHEP 1504 (2015) 105 DM , O(PeV) O(10) GeV Fermi/HESS/AMS/…

  21. Electron Channel: Super/Hyper-K (PINGU/MICA) Kaustubh Agashe, Yanou Cui, Lina Necib, Jesse Thaler JCAP 1410 (2014) no.10, 062

  22. Electron Channel: DUNE Haider Alhazmi, Kyoungchul Kong, Gopolang Mohlabeng, Jong-Chul Park JCAP 1410 (2014) no.10, 062 Lina Necib, Jarrett Moon, Taritree Wongjirad, Janet M. Conrad Phys. Rev. D 95, 075018 (2017) Galaxy Center Solar flux

  23. Conclusion The purposes of Neutrino/Proton decay experiments can be extended. • Boosted DM Striking signatures can be induced in well-motivated DM models. A wide range of parameter space has been or can be probed. Super-K is suitable for particular kinetic regime MicroBooNE/DUNE can extend both high and low energy regimes. Different channels and sources can be studied. They all have their own pros and cons. Multiple strategies are necessary to cover the models comprehensively.

  24. Neutrino experiments for boosted DM: SM Background: Atmospheric neutrino with neutral current interaction. Fake events from neutron induced elastic scattering, et. al. Possible ways to distinguish BG: Angular distribution: Angular resolution for proton in Super-K, When DM is heavy, with v = 0.6 c, Assuming isotropic background, Energy resolution: 50 MeV for LArTPCs (ICANOE in 1999) Energy differential distribution as a discriminator

  25. On-going collaborations with MicroBooNE/DUNE: Things to be addressed in MicroBooNE/DUNE: • Low energy scattering Nuclear effects: Meson Exchange Current (MEC) Resonance Inelastic Coherent Scattering Pauli Blocking (p ~ 250 MeV) • High energy scattering More likely to be Deep Inelastic Scattering. GENIE Neutrino Monte Carlo

  26. On-going collaborations with MicroBooNE/DUNE: • Detector simulation Detector reaction Energy/angular resolutions Event reconstruction efficiency DarkGeant4 Asaadi, Davenport, (UT-Arlington), Convery (SLAC), Tsai (Fermilab), Russell, Tufanli (Yale) + …

  27. Neutrino experiments for DM IND: DM in the cosmic background cannot be shielded. If they can annihilate with a proton/neutron, it can mimic a nucleon decay signal. SM objects e.g. mesons Originally proposed in Darkogenesis/Hylogenesis models (by J. Shelton, et. al. ; H. Davoudiasl, et. al. ) Two components (boson+fermion) of DM almost degenerate. Signal depending on the degeneracy.

  28. Neutrino experiments for DM IND: DM in the cosmic background cannot be shielded. If they can annihilate with a proton/neutron, it can mimic a nucleon decay signal. Induce monotonic neutrino flux from the Sun, thus can be searched in neutrino exps. Best constrained channel, thus our focus.

  29. Neutrino experiments for DM IND: The existence of DM in initial/final states modifies kinematics. • Reconstructed proton momentum < 250 MeV. • Reconstructed proton inv mass within (800 MeV, 1050 MeV). cut efficiency ~ 0.0523

  30. Neutrino experiments for DM IND: One may want to optimize the cuts respect to DM IND processes. cut efficiency mildly changes with DM mass cut efficiency ~ 0.2 not crazy to cut on P < 400 MeV

  31. Neutrino experiments for DM IND: A benchmark point in our model consistent with all experiments. (All SM charged particles are ~ TeV scale.) with improved efficiency ~ 0.2 with current efficiency ~ 0.05

  32. Joachim Kopp, Jia Liu, Xiao-Ping Wang, JHEP 1504 (2015) 105

  33. Detect BDM: Our studies focus on the Sun as the source and DM-p/n scattering. Variations on this idea: Galaxy as the source and/or DM-electron scattering electron K. Agashe, et. al. JCAP (2014) L. Necib, et. al. arXiv:1610.03486 [hep-ph] H. Alhazmi, et. al. arXiv:1611.09866 [hep-ph] …. Concerns: • More model-dependent parameters are needed. • Larger SM background for electron channel (NC vs CC interaction rate). • Neutrino beam induced beta decay as additional background.

  34. Boosted DM flux: Solar capture rate: Benchmark point: SD enhanced due to a larger velocity from solar gravitational potential Flux from the solar capture:

  35. Boosted DM flux: Subtleties: • Equilibrium is reached between DM annihilation and capture. • DM annihilation is dominated by unconventional channels. • DM is not too light to evaporate away. • DM is not blocked when it flies away from the Sun. DM annihilation cross section passes the threshold p-wave annihilation for benchmark operators Not considering v operators 4

  36. Backup slides: Model dependent: mediator mass/width/coupling (LUX arXiv:1602.03489)

  37. Backup slides: (LUX arXiv:1602.03489)

  38. Backup slides: -45 2 10 cm

  39. Backup slides:

  40. Backup slides: M ~ 400 GeV If M ~ 10 GeV, couplings ~ 0.025. Both Z’ being off-shell and small couplings are helping. med Mono-jet cross section is too small to be relevant!

  41. Unconventional Dark Matter: Anything beyond conventional scenarios? • DM sector may have multiple kinds of particles. An alien scientist from DM sector finds that 5% of the energy density in the current Universe is invisible to them! It must be SU(3)  SU(2)  U(1)!

  42. Neutrino experiments for boosted DM: Results: Axially coupled Z’, v 0

  43. Neutrino experiments for boosted DM: Results: for a fixed DM IND cross section (only important for turning point) σ ~ v 0 elastic PICO-2L, 2015, proton LUX, 2016, neutron σ ~ v 2 elastic

  44. Dark Matter Overview: J. Berger, Y. Cui, Y.Z. JCAP, (2015) K. Agashe, G. Servant, P.R.L. (2004) F. D’Eramo and J. Thaler JHEP (2010) Why do we need DM? • The CMB Anisotropy Power Spectrum (WMAP year 5 data)

  45. LUX ~ O(ton) Conventional channels: WIMP: Relic abundance & EW scale New Physics Decades of efforts focused on WIMPs! So far, no solid evidence on discovery!

  46. Neutrino experiments for boosted DM: Boost factors for DM particle in the final state: Z invariant (semi-annihilation) 3 almost at the sweet spot for Super/Hyper-K (head on collision) Two component DM a wide range, not necessarily best for Super/Hyper-K DM Induced Nucleon Decay Too small to pass the energy threshold for Super/Hyper-K! May look for neutron by doping Gd ion. Perfectly fine for MicroBooNE/DUNE!

  47. Conventional searching channels: PandaX-II Collaboration Phys. Rev. Lett. 117, 121303 Looking for DM-nucleus scattering. O(GeV) DM with O(keV) kinetic energy. Impose strong constraints to WIMP scenario.

  48. Conventional searching channels: AMS-02 Looking for DM annihilation/decay products. May be related to DM thermal relic abundance.

  49. Conventional searching channels: Looking for DM production . Good for certain DM models where (in)direct detections may suffer from velocity suppression or spin dependence.

  50. WIMP Miracle: Kolb & Turner Weakly Interacting Massive Particle (WIMP): electroweak scale new stable particles + O(1) couplings naturally show up in physics beyond SM, associated to hierarchy problem relic abundance at correct order of magnitude

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