Boosted Dark Matter Signatures at Neutrino Experiments Yue

Boosted Dark Matter Signatures at Neutrino Experiments Yue Zhao TDLI & SJTU MCTP, University of Michigan Nu. Fact 2017, WG 5

Outline: DM review Unconventional DM Models Overview on detecting boosted DM and DM IND A review on related works

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)

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

Dark Matter Overview: Some basic facts we roughly know so far: 8. 5 kpc Local DM energy density: Local DM velocity:

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

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)

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 ~ 50 K ton! DUNE ~ 68 K ton!

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 ~ 50 K ton! DUNE ~ 68 K ton!

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 Large Volume Nucleon Decay Experiments Darkogenesis model, J. Shelton, et. al. PRD (2010) Super-K ~ 50 K ton! DUNE ~ 68 K ton! Hylogenesis model, H. Davoudiasl, et. al. PRL (2010)

Boosted DM flux: (Extra)Galactic flux Flux is determined by interaction rate and distance. concentrated volume of DM 8. 5 kpc Galaxy center: Extragalactic flux is also a choice. nearby sources

Boosted DM flux: Sun (Jupiter/Earth) Flux is determined by interaction rate and distance. concentrated volume of DM nearby sources 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.

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. B 743 (2015) 256 -266

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

Neutrino experiments for boosted DM: Multiple choices: • Super/Hyper-Kamiokande (50~1000 K ton) Cherenkov ring detector Limited energy range not too low: proton momentum > 1. 07 Ge. V (no signal) not too high: proton momentum < 2 Ge. V (inelastic scattering, messy final states) • Micro. Boo. NE/DUNE (0. 17~68 K ton) Liquid Argon Time Projection Chambers (LAr. TPCs) Lower energy threshold Better control/identification on hadronic activity Better angular resolution • Ice. Cube/PINGU/MICA (~1 M ton) Photomultiplier Tube Energy threshold is 100 Ge. V But may be lowered in the future.

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 • Ice. Cube (PINGU/MICA)

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! SK I-IV: 4438. 2 days Particularly useful in low mass regime and operators with velocity suppression! HK: 4438. 2 days, angular infor.

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

Nucleon Channel: DUNE Signals can have more structures if more assumptions are imposed. Doojin Kim, Jong-Chul Park, Seodong Shin ar. Xiv: 1612. 06867 [hep-ph]

Nucleon Channel: Ice. Cube DM , O(Pe. V) O(10) Ge. V Joachim Kopp, Jia Liu, Xiao-Ping Wang, JHEP 1504 (2015) 105 Fermi/HESS/AMS/…

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

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

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 Micro. Boo. NE/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.

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 Me. V for LAr. TPCs (ICANOE in 1999) Energy differential distribution as a discriminator

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

On-going collaborations with Micro. Boo. NE/DUNE: • Detector simulation Detector reaction Energy/angular resolutions Event reconstruction efficiency Dark. Geant 4 Asaadi, Davenport, (UT-Arlington), Convery (SLAC), Tsai (Fermilab), Russell, Tufanli (Yale) + …

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.

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.

Neutrino experiments for DM IND: The existence of DM in initial/final states modifies kinematics. • Reconstructed proton momentum < 250 Me. V. • Reconstructed proton inv mass within (800 Me. V, 1050 Me. V). cut efficiency ~ 0. 0523

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 Me. V

Neutrino experiments for DM IND: with improved efficiency ~ 0. 2 with current efficiency ~ 0. 05 A benchmark point in our model consistent with all experiments. (All SM charged particles are ~ Te. V scale. )

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

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. ar. Xiv: 1610. 03486 [hep-ph] H. Alhazmi, et. al. ar. Xiv: 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.

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

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

Backup slides: Model dependent: mediator mass/width/coupling (LUX ar. Xiv: 1602. 03489)

Backup slides: (LUX ar. Xiv: 1602. 03489)

Backup slides: -45 2 10 cm

Backup slides:

Backup slides: M ~ 400 Ge. V If M ~ 10 Ge. V, couplings ~ 0. 025. med Both Z’ being off-shell and small couplings are helping. Mono-jet cross section is too small to be relevant!

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)!

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

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

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

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!

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 Micro. Boo. NE/DUNE!

Conventional searching channels: Panda. X-II Collaboration Phys. Rev. Lett. 117, 121303 Looking for DM-nucleus scattering. O(Ge. V) DM with O(ke. V) kinetic energy. Impose strong constraints to WIMP scenario.

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

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

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