Dark Matter Detection with Angular Power Spectrum Marco Chianese 5 - - PowerPoint PPT Presentation

Dark Matter Detection with Angular Power Spectrum

• MC, Fiorillo, Miele, Morisi, Pisanti, JCAP 1911 [arXiv:1907.11222]
• Dekker, MC, Ando, arXiv:1910:12917

Marco Chianese

5 March 2020, 1st Joint Nikhef+Grappa Neutrino Meeting

Marco Chianese | GRAPPA 1

Multi-messenger searches

Dark Matter particles can decay/annihilate producing:

• Neutrinos travel in straight lines


(IceCube and ANTARES/KM3NeT)

• Gamma-rays have to be propagated


(Fermi-LAT, HAWC, H.E.S.S., CTA, …) Neutrino and Gamma-Ray Telescopes provide important information about DM IceCube ANTARES

Fermi-LAT

Inverse Compton

• n the CMB

DM

γ

γ

e±

ν

Marco Chianese | GRAPPA 2

Tension with a single power-law

• Fermi mechanism:
• p-p sources:
• Blazar TXS 0506+056:

γastro ≤ 2.2

γastro = 2.0

γastro = 2.1 ± 0.2

Spectral index, γastro

Φastro

Kopper, PoS ICRC2017 981 Schneider, PoS ICRC2019 1004

3 × Φastro

Spectral index, γastro

IceCube @ ICRC2019 IceCube @ ICRC2017

TG HESE

Tension between HESE (full sky) and
 Through-Going (Northern hemisphere)

Marco Chianese | GRAPPA 3

The low energy excess

Energy [GeV] Residuals Residuals

MC, Mele, Miele, Migliozzi, Morisi, ApJ 851 (2017)

Residuals with respect to an astrophysical power-law with spectral index 2.0

Marco Chianese | GRAPPA

Possible explanations:

• Hidden astrophysical sources

The low energy excess

Energy [GeV] Residuals Residuals

Kimura, Murase, Toma, ApJ 806 (2015)
 Murase, Guetta, Ahlers, PRL 116 (2016)
 Tamborra, Ando, PRD 93 (2016)
 Senno, Murase, Meszaros, PRD 93 (2016)
 Denton, Tamborra, ApJ 855 (2018) Denton, Tamborra, JCAP 1804 MC, Mele, Miele, Migliozzi, Morisi, ApJ 851 (2017) 3

Marco Chianese | GRAPPA

The low energy excess

Energy [GeV] Residuals Residuals

Possible explanations:

• Hidden astrophysical sources
• Active neutrino decays

Kimura, Murase, Toma, ApJ 806 (2015)
 Murase, Guetta, Ahlers, PRL 116 (2016)
 Tamborra, Ando, PRD 93 (2016)
 Senno, Murase, Meszaros, PRD 93 (2016)
 Denton, Tamborra, ApJ 855 (2018) Denton, Tamborra, JCAP 1804 Denton, Tamborra, PRL 121 (2018) MC, Mele, Miele, Migliozzi, Morisi, ApJ 851 (2017) 3

Marco Chianese | GRAPPA

Possible explanations:

• Hidden astrophysical sources
• Active neutrino decays
• Heavy Dark Matter at 100 TeV

The low energy excess

Energy [GeV] Residuals Residuals

MC, Miele, Morisi, Vitagliano, PLB 757 (2016)
 MC, Miele, Morisi, JCAP 1701 MC, Miele, Morisi, PLB 773 (2017) Kimura, Murase, Toma, ApJ 806 (2015)
 Murase, Guetta, Ahlers, PRL 116 (2016)
 Tamborra, Ando, PRD 93 (2016)
 Senno, Murase, Meszaros, PRD 93 (2016)
 Denton, Tamborra, ApJ 855 (2018) Denton, Tamborra, JCAP 1804 Denton, Tamborra, PRL 121 (2018) MC, Mele, Miele, Migliozzi, Morisi, ApJ 851 (2017) 3

Marco Chianese | GRAPPA

DM Astro Bkg DM Astro Bkg 7.5yr HESE 7.5yr HESE

no prior no prior 4

Fits of IceCube spectrum

DM − → W + + W −

DM − → νe + νe

OUR HYPOTHESIS


(TWO-COMPONENT FLUX)

dφsignal dEνdΩ = Φastro E−γastro

ν

+ dφDM dEνdΩ

Marco Chianese | GRAPPA

DM → b¯ b

DM → τ +τ −

τDM [sec]

Relative Log-Likelihood γAstro = 2.69

best-fit:

γAstro = 3.19

best-fit:

Fermi-LAT constraints Fermi-LAT constraints

12 10 8 6 4 2 106 107 1027 1028 1029 1030 1028 1027 1026 1025 106 107

Leptonic channel Hadronic channel

mDM [GeV]

mDM [GeV]

5

Leptonic versus hadronic channels

Astrophysical parameters
 as nuisance parameters WITHOUT PRIOR

Φastro, astro ✏ [1.5, 5.0]

Marco Chianese | GRAPPA

DM → b¯ b

DM → τ +τ −

τDM [sec]

Relative Log-Likelihood

best-fit: best-fit:

Fermi-LAT constraints Fermi-LAT constraints

12 10 8 6 4 2 106 107 1027 1028 1029 1030 1028 1027 1026 1025 106 107

Leptonic channel Hadronic channel γAstro = 2.42

γAstro = 2.43

mDM [GeV]

mDM [GeV]

5

Astrophysical parameters
 as nuisance parameters WITH TG PRIOR

p (γastro) = N

• µTG

γ

, σTG

γ

• <latexit sha1_base64="2eZ7J79bfKVYWzB4U4rgXcUH0g=">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</latexit>

p (Φastro) = N

• µTG

Φ , σTG Φ

• <latexit sha1_base64="7q0FWrqi1Fnzcjb+oa5mn+c+2U=">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</latexit>

Leptonic versus hadronic channels

Marco Chianese | GRAPPA

How can we discriminate a Dark Matter signal from other (astro) components?

Dekker, MC, Ando, arXiv:1910:12917

Marco Chianese | GRAPPA

6yr HESE

6

Angular analysis!

GALACTIC SOURCES DECAYING DARK MATTER

Esmaili, Kang, Serpico, JCAP 1412 Denton, Marfatia, Weiler, JCAP 1708

• Neutrino sky map compatible with

isotropic flux (extragalactic sources)

• BUT… there may be a galactic

component (tension between HESE and TG)

Marco Chianese | GRAPPA

6yr HESE

6

Angular analysis!

• Neutrino sky map compatible with

isotropic flux (extragalactic sources)

• BUT… there may be a galactic

component (tension between HESE and TG)

GALACTIC SOURCES DECAYING DARK MATTER

Esmaili, Kang, Serpico, JCAP 1412 Denton, Marfatia, Weiler, JCAP 1708

LESS THAN 10% SLIGHTLY FAVOURED

Marco Chianese | GRAPPA 7

Anisotropy of Dark Matter flux

dφDM

gal.

dEdΩ = 1 2 hσvi 4π m2

DM

dNν dE Z ds ρ2 (s, l, b)

ANNIHILATION — GALACTIC

dφDM

ext.gal.

dEdΩ = 1 2 hσvi (ΩDMρcr)2 4π m2

DM

Z dz (z + 1)3B(z) H(z) dNν dE

• E0=E(1+z)

ANNIHILATION — EXTRA-GALACTIC

Cirelli et al., JCAP 1103

dφDM

gal.

dEdΩ = 1 4π mDM τDM dNν dE Z ds ρ (s, l, b)

DECAY — GALACTIC DECAY — EXTRA-GALACTIC

dφDM

ext.gal.

dEdΩ = ΩDMρc 4π mDM τDM Z dz 1 H(z) dNν dE

• E0=E(1+z)

10−3 10−2 10−1 100 101 102 Distance, r [kpc] 10−2 10−1 100 101 102 103 104 Dark Matter density, ρDM [GeV/cm−3] NFW Einasto Isothermal Burkert Moore

DM halo density profile DM boost factor

1 2 3 4 5 6 7 Redshift, z 103 104 105 106 107 Boost Factor, B(z)

Hiroshima, Ando, Ishiyama, PRD 97 2018 (HAI) powerlaw, Mmin = 106 M Macci`

• , Mmin = 106 M

Marco Chianese | GRAPPA 8

Flux hypotheses

Null hypothesis Model

• Isotropic astrophysical flux: 10-yr Through-going
• Dark matter flux
• Isotropic astrophysical flux: 7.5-yr HESE

Monte Carlo simulations to generate sky maps

Nearly-isotropic above 60 TeV Anisotropic

Ntot (θ, φ) = Natm. + Nastro + NDM, ext.gal. + NDM, gal.

Marco Chianese | GRAPPA 9

Angular Power Spectrum

NULL HYPOTHESIS (ASTRO) MODEL (ASTRO + DEC. DM) MODEL (ASTRO + ANN. DM)

10-yr IceCube-gen2

Angular Power Spectrum

N (θ, φ) = X

lm

alm Ylm (θ, φ)

Cl = 1 2l + 1

l

X

m=−l

|alm|2

Marco Chianese | GRAPPA 10

Forecast analysis: 10-year

Model

• Decay:
• Annihilation:
• NFW and HAI boost factor

DM → τ +τ −

DM DM → τ +τ −

mDM = 400 TeV

mDM = 200 TeV

95 % CL

100 101 102 103 Dark Matter events 10−4 10−3 10−2 10−1 p-value 10-year KM3NeT

Decay Annihilation

100 101 102 103 Dark Matter events 10−4 10−3 10−2 10−1 p-value 10-year IceCube-Gen2

Decay Annihilation

95 % CL

Marco Chianese | GRAPPA

100 101 102 103 Dark Matter events 10−4 10−3 10−2 10−1 p-value 10-year KM3NeT

Decay Annihilation

100 101 102 103 Dark Matter events 10−4 10−3 10−2 10−1 p-value 10-year IceCube-Gen2

Decay Annihilation

95 % CL

10

Forecast analysis: 10-year

Model

• Decay:
• Annihilation:
• NFW and HAI boost factor

DM → τ +τ −

DM DM → τ +τ −

mDM = 400 TeV

mDM = 200 TeV

Constraints on total DM events
 from anisotropy

Marco Chianese | GRAPPA 10

Forecast analysis: 10-year

Model

• Decay:
• Annihilation:
• NFW and HAI boost factor

DM → τ +τ −

DM DM → τ +τ −

mDM = 400 TeV

mDM = 200 TeV

Constraints on total DM events
 from anisotropy Constraints on DM lifetime
 and cross-section

1024 1023 1022 1021 Dark Matter cross-section, hσvi [cm3/s] 104 103 102 101 p-value

6-yr HESE unitarity

IceCube KM3NeT IceCube-Gen2

1026 1027 1028 1029 1030 Dark Matter lifetime, τDM [s] 10−4 10−3 10−2 10−1 p-value

6-yr HESE

IceCube KM3NeT IceCube-Gen2

95 % CL

95 % CL

DECAY ANNIHILATION

Marco Chianese | GRAPPA

106 107 Dark Matter mass, mDM [GeV] 1026 1027 1028 1029 Dark Matter lifetime, τDM [s] I c e C u b e

• G

e n 2 IceCube K M 3 N e T

DM → τ +τ −, NFW

6

• y

r H E S E 7.5yr HESE best-fit

11

Decaying Dark Matter

• Exclusion at 95% CL after 10

years of observations

• Bands covering the median and

the conservative 95% sensitivity from Monte Carlo

• Gamma-ray constraints shown

with grey lines: HAWC (solid) and global (dot-dashed)

HAWC: Abeysekara et al., JCAP 1802; Global: Cohen, Murase, Rodd, Safdi, ———-Soreq, PRL 119 (2017)

Marco Chianese | GRAPPA

106 107 Dark Matter mass, mDM [GeV] 1026 1027 1028 1029 Dark Matter lifetime, τDM [s] I c e C u b e

• G

e n 2 IceCube K M 3 N e T

DM → τ +τ −, NFW

6

• y

r H E S E 7.5yr HESE best-fit

11

Decaying Dark Matter

• Exclusion at 95% CL after 10

years of observations

• Bands covering the median and

the conservative 95% sensitivity from Monte Carlo

• Gamma-ray constraints shown

with grey lines: HAWC (solid) and global (dot-dashed)

HAWC: Abeysekara et al., JCAP 1802; Global: Cohen, Murase, Rodd, Safdi, ———-Soreq, PRL 119 (2017)

ICECUBE-GEN2 WILL FIRMLY PROBE THE DARK MATTER HYPOTHESIS

Marco Chianese | GRAPPA

106 107 Dark Matter mass, mDM [GeV] 1026 1025 1024 1023 1022 1021 1020 Dark Matter cross-section, hσvi [cm3/s]

unitarity

IceCube-Gen2 IceCube KM3NeT

DM DM ! τ +τ , NFW+HAI

6

• y

r H E S E

12

Annihilating Dark Matter

• Exclusion at 95% CL after 10

years of observations

• Bands covering the median and

the conservative 95% sensitivity from Monte Carlo

• Gamma-ray constraints shown

with grey lines: HAWC (solid)

HAWC: Abeysekara et al., JCAP 1802

Marco Chianese | GRAPPA 12

Annihilating Dark Matter

• Exclusion at 95% CL after 10

years of observations

• Bands covering the median and

the conservative 95% sensitivity from Monte Carlo

• Gamma-ray constraints shown

with grey lines: HAWC (solid)

STRONGER CONSTRAINTS WRT GAMMA-RAYS, BUT UNITARITY

HAWC: Abeysekara et al., JCAP 1802

106 107 Dark Matter mass, mDM [GeV] 1026 1025 1024 1023 1022 1021 1020 Dark Matter cross-section, hσvi [cm3/s]

unitarity

IceCube-Gen2 IceCube KM3NeT

DM DM ! τ +τ , NFW+HAI

6

• y

r H E S E

Marco Chianese | GRAPPA

100 101 102 103 Dark Matter events 10−4 10−3 10−2 10−1 p-value

Isothermal NFW

13

Dependence on DM properties: decay

100 101 102 103 Dark Matter events 10−4 10−3 10−2 10−1 p-value

mDM = 4 PeV mDM = 400 TeV MASS

• Exclusion limits on the total DM

events do not significantly change.

• The constraints change when plotted

against the lifetime. Set model-independent limits on the total DM events

100 101 102 103 Dark Matter events 10−4 10−3 10−2 10−1 p-value

DM → t¯ t DM → τ +τ − HALO PROFILE CHANNEL

Marco Chianese | GRAPPA

100 101 102 103 Dark Matter events 10−4 10−3 10−2 10−1 p-value

Isothermal NFW

100 101 102 103 Dark Matter events 10−4 10−3 10−2 10−1 p-value

mDM = 2 PeV mDM = 200 TeV

14

Dependence on DM properties: annihilation

MASS

• Slightly stronger dependence on DM mass
• Constraints 70% weaker with isothermal
• Strong dependence on boost factor

The constraints on the benchmark scenario can be easily rescaled

HALO PROFILE

100 101 102 103 Dark Matter events 10−4 10−3 10−2 10−1 p-value

Macci`

• HAI

powerlaw

BOOST FACTOR

Marco Chianese | GRAPPA 15

Dependence on astrophysical power-law

101 102 103

Dark Matter events

10−4 10−3 10−2 10−1

p-value Upper limit Lower limit Best-fit Spectral index, γastro

Φastro

10yr through-going muon neutrinos

Stettner, PoS ICRC2019 1017

• No significant dependence when varying the astrophysical power-law
• Robust constraints and sensitivity to Dark Matter parameter space

Marco Chianese | GRAPPA

• Tension among different neutrino data suggesting a multi-component flux.
• We have analyzed the 7.5-year HESE data with decaying DM + astrophysical power-

law, with and without the through-going muon neutrinos prior.

• Preference of a second Dark Matter component at 68% C.L.
• Multi-messenger: diffuse searches (Fermi-LAT) more sensitive than point-like ones (CTA).

★Take-home: decaying leptophilic dark matter is a viable scenario!

• Angular Power Spectrum is a powerful tool for Dark Matter discrimination!
• Future sensitivity to DM parameters using IceCube and KM3NeT exposures

★ IC-Gen2 will firmly test the DM hypothesis exploiting angular information only! 16

Conclusions

MC, Mele, Miele, Migliozzi, Morisi, ApJ 851 (2017) MC, Fiorillo, Miele, Morisi, Pisanti, JCAP 1911 Dekker, MC, Ando, arXiv:1910:12917

Marco Chianese | GRAPPA

• Tension among different neutrino data suggesting a multi-component flux.
• We have analyzed the 7.5-year HESE data with decaying DM + astrophysical power-

law, with and without the through-going muon neutrinos prior.

• Preference of a second Dark Matter component at 68% C.L.
• Multi-messenger: diffuse searches (Fermi-LAT) more sensitive than point-like ones (CTA).

★Take-home: decaying leptophilic dark matter is a viable scenario!

• Angular Power Spectrum is a powerful tool for Dark Matter discrimination!
• Future sensitivity to DM parameters using IceCube and KM3NeT exposures

★ IC-Gen2 will firmly test the DM hypothesis exploiting angular information only! 16

Conclusions

MC, Mele, Miele, Migliozzi, Morisi, ApJ 851 (2017) Dekker, MC, Ando, arXiv:1910:12917

Thanks for listening

MC, Fiorillo, Miele, Morisi, Pisanti, JCAP 1911

Marco Chianese | GRAPPA

Backup slides

Marco Chianese | GRAPPA

100 TeV 1 PeV 10 PeV

Dark Matter at neutrino telescopes

mDM

Aisati, Gustafsson, Hambye, PR D92 (2015)
 MC, Miele, Morisi, Vitagliano, PLB 757 (2016)
 MC, Miele, Morisi, JCAP 1701 MC, Miele, Morisi, PLB 773 (2017)
 Hirishima, Kitano, Kohri, Murase, PR D97 (2018)
 Sui, Dev, JCAP 1807
 MC, Miele, Morisi, Peinado, JCAP 1812

Anisimov, Di Bari, PR D80 (2009)
 Feldstein, Kusenko, Matsumoto, Yanagida, PR D88 (2013)
 Esmaili, Serpico, JCAP 1311
 Bai, Lu, Salvado, JHEP 01 (2016)
 Ema, Jinno, Moroi, PLB 733 (2014) Bhattacharya, Reno, Sarcevic, JHEP 06 (2014) Zavala, PR D89 (2014)
 Higaki, Kitano, Sato, JHEP 07 (2014) Ema, Jinno, Moroi, JHEP 10 (2014) Rott, Kohri, Park, PR D92 (2015) Esmaili, Kang, Serpico, JCAP 1412 Fong, Minakata, Panes, Funchal, JHEP 02 (2015) Dudas, Mambrini, Olive, PR D91 (2015) Koop, Liu, Wang, JHEP 04 (2015) Murase, Laha, Ando, Ahlers, PRL 115 (2015) Anchordoqui et al, PR D92 (2015)
 MC+, JCAP 1512 Ko, Tang, PLB 751 (2015) Dev, Ghosh, Rodejohann, PLB 762 (2016) Fiorentin, Niro, Fornengo, JHEP 11 (2016) Dev, Kazanas, Mohapatra, Tepliz, Zhang, JCAP 1608 Di Bari, Ludl, Ruiz, JCAP 1611 (2016) MC, Merle, JCAP 1704 Borah et al., JHEP 09 (2017) Kachelriess, Kalashev, Kuznetsov, PR D98 (2018) Pandey, Majumdar, Halder, Banerjee, arXiv:1905.08662 Pandey, Majumdar, Halder, arXiv:1909.06839

GLOBAL ANALYSES

ANTARES, PLB 769 (2017) Battacharya, Esmaili, Ruiz, Sarcevic, JCAP 1707 IceCube, EPJ C78 (2018) Battacharya, Esmaili, Ruiz, Sarcevic, JCAP 1905 MC, Fiorillo, Miele, Morisi, Pisanti, JCAP 1911 Argüelles (IceCube), PoS ICRC2019 839 Dekker, MC, Ando, arXiv:1910.12917

Marco Chianese | GRAPPA

General thoughts on DM signals

6-year HESE

For heavy DM, the annihilation rates are negligible with respect to the decay ones. In case of mDM = 1 PeV, we have:

• Annihilation
• Decay

Γevents / ✓ ρDM mDM ◆2 hσ vi . 1 per few hundred years

Γevents ∝ ρDM mDM 1 τDM ∼ ✓1828 sec τDM ◆ /year

hσ vi  1.5 ⇥ 10−23 cm3 s 300 km/s v 100 TeV mDM 2

Unitarity limit:

Feldstein, Kusenko, Matsumoto, Yanagida, PR D88 (2013) Zavala, PR D89 (2014) Relaxed in case of very cold DM substructures

Marco Chianese | GRAPPA

Decaying Dark Matter: top channel

106 107 Dark Matter mass, mDM [GeV] 1026 1027 1028 1029 Dark Matter lifetime, τDM [s] I c e C u b e

• G

e n 2 IceCube K M 3 N e T

DM → tt, NFW

6-yr HESE 7.5yr HESE best-fit

Marco Chianese | GRAPPA

Annihilating Dark Matter: top channel

106 107 Dark Matter mass, mDM [GeV] 1026 1025 1024 1023 1022 1021 1020 Dark Matter cross-section, hσvi [cm3/s]

unitarity

I c e C u b e

• G

e n 2 I c e C u b e K M 3 N e T

DM DM ! tt, NFW+HAI

6-yr HESE

Marco Chianese | GRAPPA

Neutrino sky maps

Nν (θ, φ) = Z

∆Ω

dΩ Z Emax

Eth

dEν X

α

fα dΦνα+¯

να

dEν dΩ Eα(Eν, Ω) vis(Ω)

Number of neutrino events in a region of the sky ∆Ω identified by the position θ (declination) and φ (right ascension) Total neutrino flux

Marco Chianese | GRAPPA

Neutrino sky maps

Nν (θ, φ) = Z

∆Ω

dΩ Z Emax

Eth

dEν X

α

fα dΦνα+¯

να

dEν dΩ Eα(Eν, Ω) vis(Ω)

Integrated over energy

Emax = mDM, mDM/2

Eth = 60 TeV

decay annihilation

Marco Chianese | GRAPPA

Neutrino sky maps

Nν (θ, φ) = Z

∆Ω

dΩ Z Emax

Eth

dEν X

α

fα dΦνα+¯

να

dEν dΩ Eα(Eν, Ω) vis(Ω)

Integrated over energy

Emax = mDM, mDM/2

Eth = 60 TeV

decay annihilation

Topology

• Showers in IceCube:
• Tracks in KM3NeT:

fe = fτ = 1 , fµ = 0

fe = fτ = 0 , fµ ' 0.8

Marco Chianese | GRAPPA

Neutrino sky maps

Nν (θ, φ) = Z

∆Ω

dΩ Z Emax

Eth

dEν X

α

fα dΦνα+¯

να

dEν dΩ Eα(Eν, Ω) vis(Ω)

Integrated over energy

Emax = mDM, mDM/2

Eth = 60 TeV

decay annihilation

Topology

• Showers in IceCube:
• Tracks in KM3NeT:

fe = fτ = 1 , fµ = 0

fe = fτ = 0 , fµ ' 0.8

Detector properties

Eα : effective area

HESE (IceCube) TG (KM3NeT)

Visibility[%]

KM3NeT

• IceCube visibility is 100% thanks to self-veto

Marco Chianese | GRAPPA

Decaying Dark Matter flux

DM → q¯ q

DM → W +W −, ZZ, hh

DM → `¯ `, ⌫⌫

leptophilic hadrons EW bosons

• Different final states:

Electroweak corrections
 are important!

Ciafaloni et al., JCAP 1103

GALACTIC

dφDM

gal.

dEdΩ = 1 4π mDM τDM dNν dE Z ds ρ (s, l, b)

EXTRA-GALACTIC

dφDM

ext.gal.

dEdΩ = ΩDMρc 4π mDM τDM Z dz 1 H(z) dNν dE

• E0=E(1+z)

∆σ σ ⇠ αEW ln2 ✓m2

DM

M 2

Z

◆ ' 75% for mDM = TeV

Marco Chianese | GRAPPA

Neutrino spectrum: PPPC vs PYTHIA

χ->ττ,mDM=1 PeV 103 105 104 105 10-6 10-5 10-4 E [GeV] dNγ/dE [GeV-1]

GAMMA-RAYS ELECTRONS

Perfect agreement between PYTHIA and the rescaling of the fluxes provided by PPPC up to 100 TeV

PYTHIA: Sjöstrand et al., Comput. Phys. Commun. 159 (2015) PPPC: Cirelli et al., JCAP 1103

χ->ττ,mDM=1 PeV 103 105 104 105 10-6 10-5 10-4 E [GeV] dNe/dE [GeV-1]

dNν / dE ⇥ GeV−1⇤

dNν / dE ⇥ GeV−1⇤

DM → τ +τ −

mDM = 1 PeV

DM → τ +τ −

mDM = 1 PeV

χ->ττ,mDM=1 PeV 103 105 104 105 10-6 10-5 10-4 10-3 E [GeV] dNν/dE [GeV-1]

dNν / dE ⇥ GeV−1⇤

E ⇥ GeV−1⇤

DM → τ +τ −

mDM = 1 PeV

PPPC (with extrapolation)
 PYTHIA

E ⇥ GeV−1⇤

NEUTRINOS

Marco Chianese | GRAPPA

Latest analysis on 7.5yr HESE

f.u. ≡ TeV−1cm−2s−1sr−1

Marco Chianese | GRAPPA

Latest analysis on 7.5yr HESE

TeV scale PeV scale DM flux f.u. ≡ TeV−1cm−2s−1sr−1

Marco Chianese | GRAPPA

Latest analysis on 7.5yr HESE

TeV scale PeV scale DM flux Spectral index
 larger
 than single PL Spectral index
 smaller
 than single PL Astro flux f.u. ≡ TeV−1cm−2s−1sr−1

Marco Chianese | GRAPPA

Latest analysis on 7.5yr HESE

TeV scale PeV scale DM flux Spectral index
 larger
 than single PL Spectral index
 smaller
 than single PL Astro flux

Hadronic/EW boson channels are excluded by Gamma-Rays

f.u. ≡ TeV−1cm−2s−1sr−1

Gamma-rays constraints: Cohen et al., PRL 119 (2017); Blanco and Cooper, JCAP 1903; Ishiwata et al., ariXiv:1907.11671

Marco Chianese | GRAPPA

Dark Matter parameter space

DM → t¯ t

DM → hh

τDM [sec] τDM [sec]

1028 1027 1026 1025 1027 1028 1029 1030 106 107

τDM [sec] τDM [sec]

DM → νν

DM → W +W −

106 107 1027 1028 1029
 1030 1027 1028 1029
 1030

Relative Log-Likelihood Relative Log-Likelihood

12 10 8 6 4 2 12 10 8 6 4 2

best-fit: γAstro = 3.33

best-fit: γAstro = 2.69

best-fit: γAstro = 2.67

best-fit: γAstro = 2.66

Fermi-LAT constraints Fermi-LAT constraints Fermi-LAT constraints

mDM [GeV]

mDM [GeV]

Marco Chianese | GRAPPA

Dark Matter parameter space

DM → t¯ t

DM → hh

τDM [sec] τDM [sec]

1028 1027 1026 1025 1027 1028 1029 1030 106 107

τDM [sec] τDM [sec]

DM → νν

DM → W +W −

106 107 1027 1028 1029
 1030 1027 1028 1029
 1030

Relative Log-Likelihood Relative Log-Likelihood

12 10 8 6 4 2 12 10 8 6 4 2

best-fit: γAstro = 3.33

best-fit: γAstro = 2.69

best-fit: γAstro = 2.67

best-fit: γAstro = 2.66

Fermi-LAT constraints Fermi-LAT constraints Fermi-LAT constraints

mDM [GeV]

mDM [GeV]

NOT A SUBSTANTIAL IMPROVEMENT IN

DATA EXPLANATION
 (ATM. BKG. FIXED)

Marco Chianese | GRAPPA

Gamma-ray searches

• Diffuse searches provide the strongest

constraints on decaying Dark Matter.

• Point-like searches towards the Galactic

Center (as CTA) are dominated by background.

see also: M. Pierre et al., JCAP 1410; Ibarra et al., JCAP 1509; CTA, EPJ Web

• Conf. 209, 01038 (2019)

Diffuse Point-like
 2° x 2° ROI

CTA sensitivity (50 hours)

already excluded b a c k g r

• u

n d