NCBJ annual seminar, Warsaw, 15th December 2020

Galactic WIMP search with the Super-Kamiokande detector and group status in 2020

Piotr Mijakowski (BP3) OUTLINE

1. KM3NeT

2. Super-Kamiokande

3. Achievement:

„Indirect Search for Dark Maer KM3NeT deployment from the Galacc Center and Halo with the Super-Kamiokande Detector” Phys. Rev. D 102 (2020) 072002

Super-Kamiokande

P.Mijakowski 2 KM3NeT in 2020 KM3NeT Modular neutrino research infrastructure in the Mediterranean Sea

2 DETECTORS:

• ORCA (Oscillation Research with Cosmics in the Abyss), • Locaon: Toulon (FR), 6Mton, ~2.5km depth • Taking data: 6 strings now out of 115 • Expected in 2025

• ARCA (Astroparticle Research with Cosmics in the Abyss) • Locaon: Capo Pasero (IT), ~1km3, ~3.5km depth • Taking data: 1(2) strings now out of 2x115 • Expected in 2027

P.Mijakowski 4 KM3NeT-PL GROUP (2020)

• Piotr Mijakowski – coordinator, SONATA-BIS

Conference and Outreach Commiee member, Instute Board and Review & Resources Board representave

• Rafał Wojaczyński, post-doc

GC WIMP search at ORCA (sensivity), self-veto studies

• Piotr Kalaczyński, PhD

atm. ν/µ CORSIKA simulaons & data comparisons, charm/prompt flux analysis

P.Mijakowski 5 Cosmic ray muon studies

• First data available from KM3NeT- ORCA (4 strings) & KM3NeT-ARCA (2 strings) • Comparison of data vs. Monte Carlo (CORSIKA) done by Piotr Kalaczyński reconstructed • Presented in 2020 at major muon bundle cosine zenith conferences:

• NEUTRINO 2020, Chicago (online) à poster • ICHEP 2020, Prague (online) à KM3NeT-ORCA talk in the name of collaboraon (!!! for PhD student) 6 Super-Kamiokande Super-Kamiokande @ Kamioka Observatory (ICRR, University of Tokyo), Japan

neutrino electron

neutrino

40m nucleus

electron/muon/tau good separation muon/electron 40m Cherenkov ring

8 8 Super-Kamiokande PL

• Polish group expanded in 2020 thanks to new funds: Justyna Łagoda‘s SONATA-BIS

• Member status as of 2020 :

• Piotr Mijakowski à country representave, dark maer 5 new people this year: • Justyna Łagoda • Joanna Zalipska atmospheric neutrinos, T2K-SK • Lakshmi Mohan new post-doc, reflecvity/detector calibraon • Maitrayee Mandal PhD student, tau neutrino appearance analysis • Yashwanth Praphu PhD student, T2K-SK acvies 9 „Indirect Search for Dark Matter from the Galactic Center and Halo with the Super-Kamiokande Detector”

Phys. Rev. D 102 (2020) 072002 achievement GALACTIC WIMP SEARCH IDEA

χ DM annihilaon or decay • Search for neutrinos from dark matter annihilation in the Milky Way χ à diffuse signal from entire Galaxy, peaked from Galactic Center (GC)

Detector ν

• GC visibility with SK: ~64% with upward going events,

100% with contained events

• search constrains DM self-annihilation cross section <σv>

P.Mijakowski 11 GC WIMP SEARCH PAPER

ANALYSIS PUBLISHED: Phys. Rev. D 102 (2020) 072002 hps://link.aps.org/doi/10.1103/ PhysRevD.102.072002

NCBJ contribuon is 100%:

- Main analysis by PM - Cross check analysis by Katarzyna Frankiewicz (former PhD student) - all plots in paper by PM/KF - enre text by PM - PM fully responsible for publicaon process (addressing referees, supplement etc)

12 ANALYSIS IDEA - FIT

Example based on 1 sample out of 19 • Search for neutrinos from DM annihilation in the Milky way based bb-bar, Mχ=100GeV on Super-Kamiokande data (1996-2014)

• FIT: for each tested WIMP mass & ann. mode, find configuration of background and signal that would match DATA the best using reconstructed angular & momentum distributions

? DATA = SIGNAL + ν ATM

Monte Carlo P.Mijakowski 13 DM-induced signal and atmospheric ν background

P.Mijakowski 14 FIT RESULT

15 FIT RESULT – UPPER LIMITS

16 MAIN RESULT: WIMP ANNIHILATION CONSTRAINTS

Excluded above lines

SK limits the best among all neutrino searches for WIMP masses below several tens of GeV (depeneding on the annihilation mode) P.Mijakowski 17 ON-/OFF-source analysis

• Cross check analysis performed by Kasia Frankiewicz expectation for DM- and published in the same paper induced neutrinos

Search for large-scale anisotropy due to DM-induced ν's from Milky Way

• Simple idea but powerful estimate independent on any MC/syst. uncertainties

18 ON-/OFF-source result

FC/PC: 53525.8 live-days UPMU: 5628.2 live-days

DATA is consistent with background, no asymmetry in neutrino flux observed 19 ON-/OFF-source result

Fit analysis gives stronger limits In ON-/OFF-source analysis we than ON-/OFF-source demonstrated impact of DM halo model choice

above lines is excluded above lines is excluded

P.Mijakowski 20 Future: ON-/OFF-source GC WIMP search at KM3NeT-ORCA

• ON-source / OFF-source analysis is also performed by Rafał Wojaczyński to esmate KM3NeT-ORCA performance • Sensivity expected for KM3NeT-ORCA full configuraon (115 strings) within 1 year of operaon

PRELIMINARY

Super-K ANTARES

KM3NeT-ORCA sensivity Results under revision

21 SUMMARY

• „Indirect Search for Dark Maer from the Galacc Center and Halo with the Super-Kamiokande Detector“, Phys. Rev. D 102 (2020) 072002

• World best constraints on the value of dark maer self- annihilaon cross secon at neutrino telescopes for intermediate and low WIMP masses

• Clear contribuon à we are the only authors of presented analyses, authors of enre text and all plots shown in the paper

• Results shown also at >15 internaonal conferences by PM or K. Frankiewicz

P.Mijakowski 22 supplementary slides COMPARISON WITH OTHER INDIRECT SEARCHES

24 Dark Matter

25 Dark Matter Candidates Well motivated: • neutrino – ‘hot’ DM • WIMP still main MSSM non-minimal • neutralino χ SUSY ~ candidate • gravitino G • axion a • axino ã

WIMP (Weakly Interacting Massive Particle)

• neutral • long livetime • massive (GeV - TeV) • weekly interacting with matter Example interactions of neutralino χ Good WIMP candidate from SUSY à LSP neutralino χ

Jungman, Kamionkowski, Griest, Phys. Rep., 267, 195 (1996) WIMP searches SM: Standard Model particle

χ: Dark Matter particle

P.Mijakowski 27 Concept of indirect DM searches » Indirect search = search for annihilation (or decay) products of DM

» PHOTONS produced inqq most cc ,b DMb ,tt ,annihilation... (modes in π0) decays, E spectra not attenuated over χχ → ll → .....→ ν ,γ,e , p, H 2, galactic scales, W ±,Z 0,H » ANTIMATTER satellite or balloon-borne experiments, probe few kpc € distances » NEUTRINOS excellent information on source (its direction, energy) reach from dense regions like Sun, Galactic Center, core of Earth

P.Mijakowski 28 Super-Kamiokande PMT @ Kamioka Observatory (ICRR, University of Tokyo), Japan

~11k ID ~1.8k OD located 1km PMTs underground

• 50 kton of pure water 40m (22.5 kton FV) • inner (ID) & outer/veto (OD) detection regions • SK runs from 1996 • measures solar, atmospheric, 40m cosmic & accelerator neutrinos • T. K a j i t a à Nobel Prize 2015 29 Detected Cherenkov light allows for reconstruction of: • lepton momentum (neutrino energy) • lepton direction • lepton flavor (e-like vs. µ-like, good separation possible)

ν - νe + N à e +N’

P.Mijakowski 30 30 Super-K data samples Fully-contained Partially-contained Upward-going muons

» ν energy » partial Eν info reconstruction (lepton leaves » no Eν info detector) » ν direction info » excellent ν direction info » ν direction info » downward-going » e/µ identification muons are neglected possible (mainly cosmic ray µ)

31 31 Atmospheric neutrinos: main background in DM-induced ν searches

atmospheric neutrinos at SK

Monte Carlo

WIMPs • ~10 events/day • data period: 1996-2016 • ~50 000 events in total 32 Atmospheric neutrinos: main background in DM-induced ν searches

atmospheric neutrinos at SK

Monte Carlo

WIMPs • ~10 events/day • data period: 1996-2016 • ~50 000 events in total 33 DM searches at Super-K using a fit method • Search for excess of neutrinos form Earth/Sun/Milky Way • FIT: for each tested WIMP mass & ann. mode, find configuration of ATM ν + DM signal that would match DATA the best using reconstructed angular & momentum distributions + − + − χχ →νν,W W , bb,µ µ →...νe/µ/τ

Galactic WIMP search Earth WIMP search Solar WIMP search point-like source

SK DATA

ATM MC (BKG) with oscillations • In these coordinate systems signal is easy to WIMP signal distinguish from atmospheric neutrino background enhanced for illustration P.Mijakowski 34 Galactic WIMP search: signal simulation

Simulate DM signal before detection P. Gondolo et al., JCAP 07, 008 (2004) àDarkSUSY & WimpSim M. Blennow et al., arXiv: 0709.3898 (2008)

EXAMPLE: Galactic WIMP search

differential νµνµ energy spectra per DM annihilation for Mχ=100 GeV (oscillated throughout Galaxy)

P.Mijakowski 35 Galactic WIMP search: DM self-annihilation cross section

• FIT based on 90% CL upper limit lepton mom.

& cosθGC distributions, 5326-5629 live- days,1996-2016 • NFW halo model assumed

• Fit results are consistent with null WIMP contribution • 90% CL upper limit on DM self- annihilation cross

section <σAV>

2 dφΔΩ σ A ⋅V Rscρsc dN = JΔΩ 2 dE 2 4π ⋅ Mχ dE P.Mijakowski 36

€ HALO MODELS

Dark Matter Halo Solar System Position

DM mass is > 90% of Galaxy mass

• NFW is our benchmark model • Moore/Kravtsov: extreme cases Moore NFW Kravtsov simulated angular distribuons of DM-induced neutrinos

37 KM3NeT

each string has 18 DOMs

each Digital Optical Module (DOM) contains 31 PMTs

38