Indirect WIMP detection with neutrinos in Hyper-K Yusuke Koshio - PowerPoint PPT Presentation

Indirect WIMP detection with neutrinos in Hyper-K Yusuke Koshio for Hyper-K astrophysics working group Kamioka observatory, ICRR, Univ. of Tokyo Cosmic Frontier Workshop SLAC - March 7, 2013

Neutrinos generated by WIMP annihilation Trap inside the sun χ χ W, b,τ...→ν W, b,τ...→ν ✓ Annihilation in Galactic Halo, etc.. ✓ WIMP signal from the Sun χ" χ" ν" µ " Earth A.Gould, ApJ, 388, 338 (1992) Sun

Recent results Preliminary 2 1 0 2 s m K i Prelim. IceCube 2012 Prelim Super-K 2012 (bb) Prelim Super-K 2012 ( ττ ) Preliminary IceCube/DeepCore Limit IDM 2012 / arXiv:1212.4097 T. Tanaka et al. Astrophys. J. 742, 78 (2011) R. Abbasi et al. Phys. Rev. D 85, 042002 (2012) Preliminary Super-K Limit Neutrino 2012 / arXiv:1210.4161

✓ Good energy reconstruction Observation in SuperK ✓ Conserve the neutrino direction ✓ Good Particle ID QECC interaction Inner PMTs ~11000 - Important to search for the signal 0.0225 Mton from the Sun Fiduial vol. : � � � � � � � � � � � � � � � � � � � � � � � � � � � Ikeno-yama 1km ν e ""+"n" ! ""e % ""+"p " � Kamioka-cho, Gifu (2700mwe) � � Japan 3km 2km � Mozumi SK Atotsu ν µ ""+"n" ! "" µ % ""+"p " Cherenkov light 41.4m Super-Kamiokande IV Super-Kamiokande IV Run 999999 Sub 0 Event 454 Run 999999 Sub 0 Event 209 10-02-15:01:25:39 10-02-17:16:23:39 Outer Inner: 2208 hits, 9333 pe Inner: 3136 hits, 6453 pe Outer: 10 hits, 9 pe Outer: 3 hits, 2 pe charged Trigger: 0x03 Trigger: 0x03 D_wall: 1479.4 cm D_wall: 1218.7 cm mu-like, p = 1154.7 MeV/c e-like, p = 701.5 MeV/c particle Charge(pe) Charge(pe) >26.7 >26.7 23.3-26.7 23.3-26.7 20.2-23.3 20.2-23.3 17.3-20.2 17.3-20.2 14.7-17.3 14.7-17.3 12.2-14.7 12.2-14.7 10.0-12.2 10.0-12.2 8.0-10.0 8.0-10.0 6.2- 8.0 6.2- 8.0 4.7- 6.2 4.7- 6.2 3.3- 4.7 3.3- 4.7 2.2- 3.3 2.2- 3.3 1.3- 2.2 1.3- 2.2 0.7- 1.3 0.7- 1.3 0.2- 0.7 0.2- 0.7 < 0.2 < 0.2 39.3m 1300 1300 860 860 0 mu-e 0 mu-e µ !like � decays e"like � decays 688 688 1040 1040 neutrino 780 780 516 516 520 520 344 344 260 260 172 172 0 0 0 0 0 500 1000 1500 2000 0 500 1000 1500 2000 Times (ns) Times (ns)

Recent results Preliminary 2 1 0 2 s m K i Prelim. IceCube 2012 Prelim Super-K 2012 (bb) Prelim Super-K 2012 ( ττ ) Preliminary IceCube/DeepCore Limit IDM 2012 / arXiv:1212.4097 T. Tanaka et al. Astrophys. J. 742, 78 (2011) R. Abbasi et al. Phys. Rev. D 85, 042002 (2012) Preliminary Super-K Limit Neutrino 2012 / arXiv:1210.4161

Observation in SuperK ν ☜ No significant excess from the Sun Preliminary K.Choi, Neutrino 2012 sensitive to low-mass Partially (PC) Fully (FC) ν Event category ν μ ✓ Contained events stopping μ through μ ν μ ✓ Upward going muons (Upmu) Reconstructed angular spectrum of fro

Hyper-Kamiokande 25 times larger than Super-K Total vol. : 0.99 Mton Fiducial vol. : 0.56 Mton Photo-sensors : 99,000 PMTs LoI : arXiv 1109.3262

Hyper-K sensitivity IceCube(WW) arXiv 1109.3262 KIMS PICASSO AMANDA(bb) AMANDA(WW) IceCube(bb) SK(bb) ������������������������ � � SK(WW) HK 5years (bb) HK 5years (WW) IceCube+DeepCore Scale from the SK upmu results �������������������� � � (LoI) -33 10 http://dmtools.brown.edu/ Gaitskell,Mandic,Filippini -34 10 -35 10 -36 10 -37 10 -38 10 -39 10 -40 10 -41 10 2 3 4 10 10 10

Hyper-K sensitivity SK(bb) KIMS PICASSO AMANDA(bb) AMANDA(WW) IceCube(bb) IceCube(WW) SK(WW) ������������������������ � � HK 5years (bb) HK 5years (WW, ττ) IceCube+DeepCore Adding the FC+PC sample can extend the sensitivity direct to lower mass region. �������������������� � � Preliminary -33 10 http://dmtools.brown.edu/ Gaitskell,Mandic,Filippini -34 10 -35 10 -36 10 -37 10 -38 10 -39 10 -40 10 -41 10 2 3 4 10 10 10

Hyper-K sensitivity HK searches for WIMP masses favorable to other indirect direct search experiments. region suggested by the interesting WIMP mass Hyper-K. results (FC+PC+upmu) to Preliminary PINGU PINGU HK below ~20-50 GeV. Sca • Scale of achieved Super-K !7#*8 � 9$2342 :;#*8 � 9$<;8= +II+III 43 3 ./0,!!1$%2342' ",-, ' 3 4 3 2 % • Hyper-K is sensitive to the $ . . 5 1 0 � # $%#&' 5yrs 43 � 2 !7#*8 � 9$%2344' � !" /6*07&*$%2342' PINGU 5yrs • Hyper-K compares 43 � > Hyper to 43 4 43 2 43 ? ( � $%)*+'

Rest New detection channel At Decay arXiv 1210.4161 by C.Rott neutrinos up to E=52.8MeV Charged pions at rest producing Possible annihilation channels: qq,gg,cc,ss,bb,tt,W + W - , ZZ, τ + τ - , μ + μ - , νν , e + e - , γγ π + → µ + ν µ some “high energy” neutrinos in decays few neutrinos π + ⇒ basis of present day searches π - µ + → e + ν e ¯ ν µ dominant decay into hadrons π - log[dN/dE] ν μ π + π + π + π + π - 29.8MeV π + 52.8MeV γ π - π + π 0 γ ν e π + π + π + π - neutrino energy (MeV)

Backgrounds K. Bays {Super-K Collaboration} Phys.Rev. D85 (2012) 052007 ν x ν x NC Elastic e “reactor + solar” ν μ Decay electron T < 50 MeV μ e “atm. muon neutrinos” “invisible muon” ν e CC ν e e “atm. electron neutrinos” { ν x ν x µ/ π NC T > 200 MeV π “ μ / π production from ν μ atm. neutrinos” μ e “visible short muon track”

Gadolinium in water Proposal : add Gd to Super-K for SuperNova relic neutrino • • search. (Beacom & Vagins : Phys.Rev,Lett. 93(2004)171101) 0.2% Gd solution would yield >90% neutron captured. • can provide a way to discriminate against this background Identifying neutrinos of the inverse beta decay reaction • Decay electron events are the dominant background Use a delayed coincidence signal n ν e ! p Gd + e (8MeV) γ ~20 μ sec

EGADS Kamioka underground observatory (GADZOOKS!) R&D for Gd in SuperK Electronics and computer Start data taking in this Summer • Establish purification method • 200 ton tank with 232 PMTs 200#ton#water#tank# 15m3#tank � Main#water# Evaluating Gadolinium’s Action on Detector Systems circula1on#system � With PMTs, cables, black sheet and etc. � 50m トンタンク Super-Kamiokande ガドリニウム実験室全体図 experimental hole 実験室 e l b コントロール室 a c T M P control room 信号ケーブル、 ケーブル （ノイズが乗らないことは を用い て確認済み） コントロール室 セットアップ

EGADS Kamioka underground observatory Start data taking in this Summer (Gd option) R&D for Hyper-K Electronics and computer M.Yokoyama, this afternoon session • Establish purification method • 200 ton tank with 8 HPDs  200#ton#water#tank# 15m3#tank �  Main#water# Evaluating Gadolinium’s Action on Detector Systems circula1on#system �  With PMTs, cables, black sheet and etc. � 50m トンタンク Super-Kamiokande ガドリニウム実験室全体図 experimental hole 実験室   e l b ◦ コントロール室 a c T ◦ M P control room 信号ケーブル、 ケーブル （ノイズが乗らないことは を用い て確認済み） コントロール室 Photo セットアップ tube (cathode) APD Hamamatsu

Hyper-K sensitivity 10 3 THIS WORK SUPER − K (2012) PICASSO (2012) ICECUBE (2012) 10 2 − KIMS (2012) bb W + W − , τ + τ − SIMPLE (2012) χ P [pb = 10 − 36 cm 2 ] 10 1 Super-K 4yrs 1 DAMA Hyper-K 4yrs + Gadolinium 10 − 1 EVAPORATION σ SD 10 − 2 best case 10 − 3 10 − 4 1 10 100 m χ [GeV]

Galactic search HK 5years Preliminary above lines is excluded ky , C +

Hyper-Kamiokande multi-purpose detector LoI : arXiv 1109.3202 x50 of T2K Supernova Sun for ! CP ν ν ν Proton Hyper-K Decays ν x25 Larger ν Target & Proton Decay Source higher intensity ν by upgraded J-PARC x2 (year or power) 18

International HK meeting (~100 researchers) 検出器デザイン， 方針を議論 1st : 2012 Aug. 2nd : 2013 Jan. Start up an international working group < List of R&D > 36 • Physics potential • Cavity and Tank • Water system • Photo-sensor development • DAQ and electronics • software • calibration 物理感度， を結成 （ 半分国外から） 物理感度， 第 回 年 月 各 名の参加者 （ 半分国外から） を結成 36 検出器デザイン， 方針を議論 第 回 年 月 各 名の参加者 etc. 第 1 回 : 2012 年 8 月 23,24 Interna 第 2 回 : 2013 年 1 月 14,15 http://indico.ipmu.jp/indico/conferenceTimeTable.py?confId=7 http://indico.ipmu.jp/indico/conferenceTimeTable.py?confId=10

Conclusion for indirect WIMP search. reconstruction. mass region less than 50GeV. unique prospects for Hyper-K. • Water Cherenkov detector has a unique potential • Established by Super-K. • Good flavor tagging, energy and direction • Hyper-K will be most important to cover the WIMP • New low-energy neutrinos from the Sun could offer