Hyper-Kam iokande Project I ts Physics Potential Astroparticle - - PowerPoint PPT Presentation

Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

Hyper-Kam iokande Project

I ts Physics Potential Astroparticle Physics 2014

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Hiroyuki Sekiya ICRR, University of Tokyo for the Hyper-K Working Group

The Hyper-K Working Group

Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

Rem aining issues for

 Neutrino mixing parameters

• CP phase δ, Mass hierarchy| m 32

2| , octant of θ23

 Neutrinos as “astroparticles”

• Solar neutrinos

 Spectrum upturn(Solar matter effects, sterile?)  Day/ night asymmetry (Earth matter effect)

• Supernovae neutrinos

 Burst(mechanism of SN)  DSNB(history of Universe)

• High energy neutrinos

from GC, Sun, earth…

 Dark matter

 Proton decay

Atmosphere Sun Galaxy Supernovae J-Parc

All of them are statistically limited!

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

Let’s m ove on to “m ore than Super”

 Hyper-

Atmosphere Sun Galaxy Supernovae J-Parc

A prefix often used in scientific and technical words, to denote something above or beyond the usual, normal, expected, or healthy level. Sometimes used to mean extreme or specifically "more than super-".

(Wikipedia)

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

Kam ioka 3 rd Generation

1 Mt W ater Cherenkov Detector

 2 cylindrical tanks lying side-by-side (48m x 54m x 250m each)

 5 compartments in each tank w/ photo-sensitive separation walls  Each compartment is “twice the size of Super-Kamiokande II”



I D 20% photo-coverage with 99,000 20” PMTs



OD 2m layer with 25,000 8” PMTs

Fiducial vol.0.56Mt

Fiducial vol. 0.0225Mt

For solar neutrinos PMT must be doubled

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

Neutrino m ixing param eters

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

Status of ν m ixing param eters

 Recent results from T2K & reactor

T2K sin22θ13 =

(NH) (IH)

0.140−0.032 0.170−0.037

+0.044

is slightly larger than the ones from reactor experiments →indication of non-zero δcp❓

The best overlap is for the Normal hierarchy with δcp= –π/ 2!

+0.038

νe appearance c.f. Daya Bay

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

The channel νµ→νe , νµ→νe

 L= 295km , ρ= 2.6g/ cm 3 case (assuming NH, δ= -π/ 2)

neutrino Anti-neutrino

_ _

Leading sin22θ13 CPC CPV

Solar

matter

Oscillation term Measured angles

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

2 .5 o off-axis narrow band ν beam

w ith J-PARC ν beam

 J-PARC 30GeV proton beam power

will be upgrade to ＞0.75MW

 ＞１MW is under study

SuperK

2 9 5 km

~ 0.6GeV νµ cite candidates in Kamioka

2700mwe 1750mwe

ν mode ν mode _

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

expected spectra ( δ dependence)

 Full MC based on T2K experience beam BG , ν interaction, detector, reconstruction

• WC PID is excellent→ νµ CC BG rejection > 99.9%
• π0 rejection is established→NC π0 is no longer dominant BG!

ν mode 2.5 years ν mode 7.5 years

_ Total 7.5 x 107 MW·sec (10 years) Expected number of events NH, sin22θ13= 0.1, sin22θ23=1.0 δ= 0

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

sensitivity to δCP

 Use both reconstructed energy spectra and number of

• bserved events

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Determination power of δCP parameter: 1σ error of δCP is expected to be 8o ~ 19o.

Normal hierarchy Inverted hierarchy

90% CL allowed regions for δ= -90o, 0o, 90o, 180o

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

sensitivity to CPV

Mass hierarchy is assumed to be known

Normal hierarchy Fraction of δ in [−π,π]

Chance(% ) to observe CP violation

7.5 x 107 MW·sec (10 years)

 sinδ=0 exclusion (CPV sensitivity)

76% chance to observe CPV at 3σ 58% chance to observe CPV at 5σ

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

MH? atm ospheric ν!

 νe appearance probability

νμ→νe resonance

• ccurs in earth’s core.

It is either νe or νe depending on MH

Not only MH, but also has sensitivity to

• θ23 octant
• CP asymmetry

Region of interest: Multi-GeV, upward(Θ< 0) _

core

cosΘ = 1 L～1 5 ㎞

cosΘ= -1 , L～1 3 00 0 ㎞

_

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

expected zenith angle distributions for N e/ N 0

e ( MH, θ2 3dependence)

 MH difference (and θ23 octant difference) are clearly visible.

Multi-GeV νe-like Full MC 10 years

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

sensitivity to MH

 Significance ≡ ∆χ2 for wrong MH rejection Normal Hierarchy Inverted Hierarchy

∆χ2 for assuming Inverted ∆χ2 for assuming Normal sin22θ13 =0.1 HK 10 years operation

Sensitivity depends on θ23, but for most cases MH can be determined > 3σ

Band : range of CP

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

sensitivity to θ2 3 octant

 Significance ≡ ∆χ2 for wrong octant rejection

sin22θ13 =0.1 HK 10 years operation

Normal Hierarchy MH unknown Inverted Hierarchy MH unknown

Octant can be determined > 3σ if sin2θ23 < 0.47 and sin2θ23 > 0.53 for NM if sin2θ23 < 0.45 and sin2θ23 > 0.56 for IM

Band : range of CP

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

Astroparticle Neutrinos

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

sensitivity to SN burst ν

E > 10 MeV Time window = 10sec.

> 0.5

Cumulative supernova rate 1 SN about every 10 years is expected within 2 Mpc. > 50% chance for signal multiplicity of 3 for SN at 2 Mpc Hyper-K detection probability No osc. NH IH

0.1

 SN in nearby galaxies  SN in our galaxy

Huge statistics ~250k events @ 10kpc Sensitive to MH

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

sensitivity to DSNB( SN relic neutrino)

 Sensitivity depends on spallation BG by cosmic µ

SK Mozumi

Elevation data in Kamioka

HK Tochibora HK Mozumi µ flux

At Tochibora, SK x 4 spallation BG

significance LMA model

SK spallation BG

DSNB observation > 3σ in 5 years > 5σ in 10 years Adding Gd increases the significance

Expected DSNB spectra for various models years 18

Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

W I MP annihilations

 Possible annihilation channels

• χχ→qq,gg,cc,ss,bb,tt,W+ W-,ZZ,τ+τ−,µµ,νν,e+ e-,γγ

“high energy neutrinos” in decay Few neutrinos Dominant decay into hadrons

Hyper-K LOI arXiv 1109.3262

targets of usual indirect search

Charged pions decay producing neutrinos up to E=52.8MeV

“low energy neutrinos” Unique targets for SK/HK

 Up-going νµ effective area

sensitivity 3~6 x SK HK Fiducial vol.: 25 x SK HK Effective area: ~18 x SK

C.Rott et al., arXive: 1208.0827

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

WIMP mass (GeV)

sensitivity to W I MPs

In low mass region Hyper-K will be the best!

high energy ν

ττ Hyper-K 5yrs bb Hyper-K 5yrs WIMP-n spin-dependent cross section (pb)

 In the Sun

low energy ν

Model the full hadronic shower in the Sun. Minimal dependence on channels.

Hyper-K 4yrs +Gd +factor 5 BG reduction

1000 100

 In the Galaxy

Studies on Hyper-K sensitivity are on going

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

sensitivity to proton decay

 10 times better sensitivity than Super-K

• Only realistic plan to go beyond 1035 years for p→e+ π0

Hyper-K 10years sensitivities to various modes

In lucky case, 3σ discovery is possible!

p→e+ π0 1.3 x 1035 years (90% CL) 5.7 x 1034 years (3σ discovery) p→νK+ SUSY favored 3.2 x 1034 years (90% CL) 1.2 x 1034 years (3σ discovery)

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

Technical R&D

 Large cavern excavation  Water tank  Photo sensor

• High QE 20’’ BL-dynode PMTs and high

QE 20’’ HPDs will be tested in water.

Box & Line

 Water purification system  electronics

APD

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

Conclusion

 Hyper-K has great potential for wide range of Physics.

• Neutrino mixing parameters

 Discovery potential of CPV(δCP) for 76% of the region with 3σ.  Determine Mass hierarchy and θ23 octant with 3σ.

• Astrophysical neutrinos

 Burst Supernovae sensitivity Nν> 3 at 2Mpc  SRN > 3σ in 5 year w/ o Gd  Best sensitivity to Low mass WI MPs

• Proton decay

 sensitivity o(1035)years for p→e+ π0

• Other physics including unexpected

 ex. sterile/ ν mass: KOHRI ’s talk on Friday at 18: 10

 Preparation works are in progress.  Hyper-K is open to the international community.

• 5th Open Hyper-K meeting in Vancouver

July 19-22 at UBC/ TRIUMF

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

Extra slides

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

Tim eline

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Hiroyuki Sekiya TeVPA+ I DM2 0 1 4 Jun 2 5 2 0 1 4 @Am sterdam

Political

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