Novel Searches for Dark Matter with Neutrino Telescopes

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 1 Novel Searches for Dark Matter with Neutrino Telescopes Center for Cosmology and Astroparticle Physics Nov 17-18 th , 2008 Prospects for the Search for Dark Matter with Fermi Brian L. Winer The Ohio State University Fermi LAT Dark Matter and New Physics Working Group

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Prospects for the Search for Dark Matter with Fermi Brian L. Winer The Ohio State University Fermi LAT Dark Matter and New Physics Working Group. Novel Searches for Dark Matter with Neutrino Telescopes Center for Cosmology and Astroparticle Physics Nov 17-18 th , 2008. - PowerPoint PPT Presentation

Transcript of Novel Searches for Dark Matter with Neutrino Telescopes

Page 1: Novel Searches for Dark Matter with Neutrino Telescopes

Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 1

Novel Searches for Dark Matter with Neutrino Telescopes Center for Cosmology and Astroparticle Physics Nov 17-18th,

2008

Prospects for the Search for Dark Matter with Fermi Brian L. WinerThe Ohio State UniversityFermi LAT Dark Matter and New Physics Working Group

Page 2: Novel Searches for Dark Matter with Neutrino Telescopes

Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 2

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 3

WIMP annihilation: gamma-ray yield

200GeV mass WIMP

WIMP pair annihilation gamma spectrum

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 4

Dark Matter in the gamma ray skyMilky Way Halo simulated by Taylor & Babul (2005)

All-sky map of DM gamma ray emission (Baltz 2006)

Only dm annihilation radiation shown….

Galactic center

Milky Way halo

Milky Way satellites

Extragalactic sub haloes/clumps

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 5

Several Different Search Modes

Search Technique advantages challenges

Galactic center

Good Statistics

Source confusion/Diffuse background

Satellites, subhalosPoint sources

Low background,Good source id

Low statistics

Milky Way halo

Large statistics

Galactic diffuse background

Extra-galactic

Large Statistics

Astrophysics, galactic diffuse background

Spectral lines No astrophysical uncertainties, good source id

Low statistics

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 6

Total GCR protons GCR He GCR electrons albedo protons,pbar albedo positrons albedo electrons albedo gammas.

Background to all photons: Charged Particles

-Rejection power:

~105-6

-γ efficiency:

~0.8

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 7

Galactic Center

Advantage: Largest Source of DM Photons

Problems: Astrophysical Sources CR Accelarators High Energy Gamma Sources

Behavior at Fermi Energies??

Initial Sensitivity Estimation ROI = 0.5 deg of GC, E > 1 GeV Truncated NFW Profile. Simulate Particle-yield (DarkSUSY) Background:

Astrophysical Sources Subtracted

GALPROP Represents Diffuse Background Simulate Detector Response.

Consider Annihilations: (Done Individually)

bb tt W W

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 8

Dark Matter From the Galactic Center

Simple for Test Statistic. (More sophisticated TS under study)

2- similar - WW less sensitivity- more sensitive.

tt

Current Efforts: Optimize ROI (Plot) Understand Source Removal

Need data. Optimize TS.

5 Years of Sky-Survey 5 Years of Sky-Survey

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 9

Galactic Halo Analysis

Advantage: Use the large statistics of the full sky.

Challenge: Critically Dependent on Diffuse Background

Measure the sensitivity to observing a signal. ROI = R>10o or |b|>10o

NFW Profile. Diffuse Background:

GALPROP (Conv., Opt.) Simultaneous Fit to both

spatial and energydistributions

Mass vs < v> 1 year of running

Page 10: Novel Searches for Dark Matter with Neutrino Telescopes

Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 10

Galactic diffuse: conventional and optimized GALPROP model

’conventional’ GALPROP: calibrated with locally measured electron and

proton,helium spectra, as well as synchrotron emission

Optimized GALPROP:

Strong, Moskalenko, Reimer, ApJ 537, 736, 2000

Strong, Moskalenko, Reimer, ApJ 613, 962-976, 2004

Conventional Optimized

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 11

Galactic Diffuse Background: Brem

l

b

E 100 MeV

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 12

Galactic Diffuse Background: Neutral Pion Decay

l

b

E 100 MeV

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 13

Galactic Diffuse Background: Inverse Compton

l

b

E 100 MeV

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 14

Galactic Diffuse Background: Total

l

b

E 100 MeV

b 10o

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 15

Galactic Halo Analysis

Advantage: Use the large statistics of the full sky.

Challenge: Critically Dependent on Diffuse Background

Measure the sensitivity to observing a signal. ROI = R>10o or |b|>10o

NFW Profile. Diffuse Background:

GALPROP (Conv., Opt.) Simultaneous Fit to both

spatial and energydistributions

Mass vs < v> 1 year of running

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 16

Sensitivity for Galactic Halo Analysis

Conventional Diffuse Optimized Diffuse

Typical DM Photon Yields (1 year) : 1.5 x 104 (100 GeV/c2) 3 x 103 (250 GeV/c2)

50 50250 250

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 17

Halo Analysis: Mass Resolution

Warning: Statistical Uncertainty ONLY…think of this as a “best case/Lower Limit”

2501000

100

Current Efforts: Work on understanding

Diffuse Background. Optimize ROI Understand Source Removal Optimize Fitting. SYSTEMATICS! SYSTEMATICS!

For cases where we observer a signal at 5, we can determine our mass resolution.

Error bars represent the 68% CI

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 18

Search for Sub-halos

In CDM Paradigm, expect MW to contain potentially large number of sub-halos.

Sensitivity: Assumes Taylor&Babul (05) Distribution Sub-halo with Truncated NFW Profile MWIMP=100 GeV

Annihilation Background: Extragalactic,

Galactic Diffuse (GALPROP) Search for Msub>106 MO

Test Statistic:

v 2.310 26 cm3s 1

bb

lnL s b lnL(b)

.

8.9 kpc 2.7 107 Mo b = 39

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 19

Significance [ σ]

No

. o

f sa

tell

ites

Sub-halos

Fermi 1-yr

Fermi 5-yrs

WIMP mass [GeV]<σ

an

nihv >

* A

str

op

hy U

nc.

Green: GALPOP optimized

Red: GALPROP conventional

Most Sub-Halos are found a high (|b|) galactic latitude.

Once found an attempt can be made to extract the DM parameters. Below are the error ellipses for the case on the previous page.

99% CL

90% CL

68% CL

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 20

Dwarf Spheroidal Galaxies

Sagittarius DwarfAssumes 5 years of observations.

Likelihood TS: Sensitivity Improves by2-4x

Advantage: Could be DM Dominated

Disadvantage: DM Profile?

Initial Sensitivity GALPROP used for

Diffuse Test Statistic:

Simple: Recent: Likelihood

If NFW Profile, sens afactor of 10 less.

Other dSph (e.g. Draco)will also be studied.

2

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 21

Line Search Simulated detector response to δ function in energy

)()( 2min

2min

2 bbs

Advantage: ”Smoking Gun” Backgrounds from data

Challenges: Small BR <10-3

Energy Resolution. Initial Sensitivity Estimation

ROI = Broken Annulus 20o < R < 35o ; |b|>15o DM Den High but reduced

background Scan through energy range Fit Background to exponential Signal Fit Double Gaussian Test Statistic:

Example MC Sim.

Proposed by Stoehr, et al

Some recent models predict enhancements.

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 22

Line 5σ sensitivity

5 Years of Fermi Data

Current Efforts: Improved event selection and

energy reconstruction. Optimized ROI

Need data Measure Diffuse Bkg. Optimize TS.

Trials factor included for unknown source.

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 23

Summary

Fermi has many targets for the indirect DM search. Some are statistics limited. Some are sys. limited Other Modes:

Cosmological WIMPS Extra Dim: KK HE Electrons

Efforts are on-going to optimize these searches. Real Data Helps!

The DM Working Group plans an intense effort in the first year of operation. We are happy finally to be in

orbit!

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 24

WIMP annihilation: gamma-ray fluxWIMP annihilation: gamma-ray flux

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 25

Acknowledgements

E Baltz, B. Berenji, E. Bloom, J. Chiang, Y. Edmonds, G. Godfrey, P. Wang, L. Wai, J. Cohen-Tanugi(SLAC/KIPAC)

I. Moskalenko (Stanford) A. Morselli, A. Lionetto (INFN Roma/Tor Vergata) E. Nuss (Montpellier) R. Hughes, A. Sander, P. Smith, B. Winer (Ohio State) L. Bergström, T. Bringmann, J. Conrad, J. Edsjö, A. Sellerholm

(Stockholm) A. Moiseev (Goddard) G. Bertone (Paris) R. Johnson(Santa Cruz) J. Ormes (Denver) R. Rando (Padova) A. Strong (Max-Planck)

Pre-launch Estimates for GLAST Sensitivity to Dark Matter Annihilation SignalsE. A. Baltz, et al JCAP, 07 (2008) 013, arXiv: 0806.2911v2

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 26

Parameter Space

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Brian L. Winer, Ohio State University Fermi Gamma-Ray Space Telescope CCAPP DM Workshop Page 27

Cosmological WIMPS