EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE...

28
EHE Neutrino Search with the IceCube Aya Ishihara Aya Ishihara The University of Wisconsin - Madison The University of Wisconsin - Madison for the EHE Verification working group for the EHE Verification working group
  • date post

    19-Dec-2015
  • Category

    Documents

  • view

    213
  • download

    0

Transcript of EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE...

Page 1: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

EHE Neutrino Search with the IceCube

Aya IshiharaAya IshiharaThe University of Wisconsin - MadisonThe University of Wisconsin - Madisonfor the EHE Verification working groupfor the EHE Verification working group

Page 2: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Outline

Expected the highest energy region signal neutrinos

How they might look like from the point of IceCube detector

Results from MC simulation analysis with full and this year’s configuration

Outlook toward real data analysis with 9 strings

Page 3: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Recent Activities by EHE Working Group

Convener: Shigeru Y.

Muon Reconstruction: Sean G., Keiichi M., David B.

Tau Reconstruction: Rodin P.

MC study: Shigeru, Kotoyo H., Aya I.

MC (semi-) mass production: Paolo D., Keiichi

Data check: Hiroko M., Kotoyo, Aya

See Shigeru’s talk @ analysis session on Thursday

Page 4: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Extremely High Energy Neutrino

Possible Signals… Standard scenariosEx. GZK mechanism – EHE cosmic-ray induced neutrinos

( E ~ 109-10 GeV )

Exotic scenariosEx. Top-Down – decays/interaction of massive particles

( E ~ 1011-15 GeV )

seXp K '7.2

xM

Page 5: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

EHE Neutrino with km3 Detector (I)

Where to look for events?

Filtering from large background - Atmospheric distinguishable by their energy

Need good energy resolution

EHE neutrino mean free path ~ 100 km << REarth

down-going

up-going

EHE neutrino events are down-goingNot up-going

Page 6: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

EHE Neutrino with km3 Detector (II)

How do they look like?

Series of cascade

Energy deposit indicates the primary particle energy

e+e-

pair-creation

bremsstrahlung

photo-nuclear

Page 7: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

IceCube EHE Event Channels

Possible EHE particles in depth

Atm

Secondary and

EGZK >> EAtm

Fluxes at the IceCube depth

Page 8: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

MC Simulation SetupEvent Samples Muon events with E-1 spectra 95,000 events Muon events with E-2 spectra 110,000 events Tau events with E-1 spectra 99,000 events 105 GeV ~ 1011 GeV

Page 9: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Simple Primary Energy Indicator

Estimated total number of photo-electrons per event

ContainedUncontained

ContainedUncontained

Page 10: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

How NPE is Estimated from Waveforms (I)

Log

10 (A

TW

D e

stim

ated

NP

E)

Estimated number of photo-electrons per DOM

ATWD or FADC?

Log

10 (F

AD

C b

ased

est

imat

ed N

PE

)

Log10 (ATWD based estimated NPE)

L

og10

(FA

DC

est

imat

ed N

PE

)

Log10 (MC Truth NPE) Log10 (MC Truth NPE)

Red: DOM of which ATWD charge is largerBlue: DOM FADC is larger

Integrated charge over a waveformdivided by single pe charge

Page 11: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

How NPE is Estimated from Waveforms (II)

MC Truth NPE vs. Larger Charge waveform based estimated NPEper DOM

Log10 (MC Truth NPE)

Log

10 (

Bes

t es

tim

ated

NP

E)

This,“use the larger charge waveform”,

in principle applies also for the finer waveform based reco

Page 12: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Signal vs. Background: Energy/event-sum NPE

GZK Atmospheric GZK

Contained events only

Page 13: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Event Rate without Background Cut

GZKGZK

Atmospheric

GZKGZK

Atmospheric

Zenith angleNPE

up down

Page 14: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Signal Domain: Zenith/NPE

GZK Atmospheric

Page 15: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Event Rate in Signal Domain

GZK 3.5 events/year

GZK 0.56events/year

Atmospheric 0.33 events/year

GZKGZK

Atmospheric

GZKGZK

Atmospheric

Page 16: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Event Rate based on simple reconstruction

GZKGZK

Atmospheric

GZKGZK

Atmospheric

Page 17: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Event Rate with 9-strings

GZK 0.67 events/year

Atmospheric 0.0085 events/year

GZKAtmospheric

GZKAtmospheric

AMANDA

IceCube

Page 18: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

For taus…

GZK Atmospheric

Assuming we have extremely good geometrical reconstruction,

Page 19: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Event Rate with the optimistic cut

GZKGZK

Atmospheric

GZKGZK

Atmospheric

Page 20: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Muon Effective Area – Full String

Black (up-going):

-1.0 < cos(MC) < -0.8

Red:

-0.6 cos(MC) < -0.4

Blue (horizontal, slightly up-going)

-0.2 < cos(MC) < 0.0

Pink:

0.4 < cos(MC) < 0.6

Green (down-going):

0.8 < cos(MC) < 1.0

Page 21: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Effective Area – 9 strings~10 % strings are much more than 10 % as an effective area !

Black (up-going):

-1.0 < cos(MC) < -0.8

Red:

-0.6 cos(MC) < -0.4

Blue (horizontal, slightly up-going)

-0.2 < cos(MC) < 0.0

Pink:

0.4 < cos(MC) < 0.6

Green (down-going):

0.8 < cos(MC) < 1.0

Page 22: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Summary and Outlook

IceCube is indeed capable of detecting EHE neutrinos with both full and this year’s 9-string configuration

First-level background filtering can be done with very simple parameters such as NPE-sum, zenith

Further understandings of detector performance

Comparison between real data and MC simulation

Energy and geometrical reconstructions!!

Page 23: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Extra

Page 24: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

N_DOM vs. NPE with 9 strings

Page 25: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

April 11, 2006 IceCube Collaboration Meeting

25

Event Rate vs. Primary Energy

Page 26: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

Predicted Fluxes

Page 27: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

9-string Geo

Page 28: EHE Neutrino Search with the IceCube Aya Ishihara The University of Wisconsin - Madison for the EHE Verification working group.

The IceCube Detector