High-Energy Neutinosfrom

Multi-body Decaying Dark Matter

NagisaHiroshima1,2,RyuichiroKitano2,3,KazunoriKohri2,3,5,Kohta Murase4

(1:ICRR,TheUniv.ofTokyo,2:IPNS,KEK,3:SOKENDAI,4:Penn-StateUniv.,5:Univ.ofOxford)

reference:Phys.Rev.D.,97.,023006

KEK-PH2018.2.13- 2018.2.16

High-Energy Neutinosfrom

Multi-body Decaying Dark Matter

DMν

mDM=O(1)PeV

...

N~30particles!

S

S...

S

S

Outline:

1,Introduction

2,Model

3,Result(s)

4,Summary

IntroductionWhatarethemotivationsforourmulti-bodydecayingDM?

TeV-PeV neutrinos@IceCube

IceCube Collaboration,1701.03731

!2#Φ# ∝ !-2.5

OriginoftheTeV-PeV neutrino1,AstrophysicalSources:cosmicrayprotoninteractions

2,DarkMatter:DM->ν +...

•p+p->p,p,π0,π+,π- +...

•p+γ ->p,π0 orπ+ orπ- +...

e.g.GRB,AGN,Starburstgalaxies,...

γ +...l+ +l- +...->inversecompton γ +...q,q+...->p+p+π0 +π+ π- +...

->p+p+ν +e+ +e- +γ +...

Ep ~O(108)GeV

Ep ~O(106)GeV

->p+ν +e+ +e- ,γ,...

->p+ν +e+ +e- orγ ...

OriginoftheTeV-PeV neutrino1,AstrophysicalSources:cosmicrayprotoninteractions

2,DarkMatter:DM->ν +...

•p+p->p,p,π0,π+,π- +...

•p+γ ->p,π0 orπ+ orπ- +...

e.g.GRB,AGN,Starburstgalaxies,...

γ +...l+ +l- +...->inversecompton γ +...q,q+...->p+p+π0 +π+ π- +...

->p+p+ν +e+ +e- +γ +...

Ep ~O(108)GeV

Ep ~O(106)GeV

->p+ν +e+ +e- ,γ,...

->p+ν +e+ +e- orγ ...

Neutrinos often associate γ-rays

Problem1:Istropic γ-rayBackground(IGRB)

(Kalashev &Troitsky,1608.07421)

Φγ�Φν �higher γ-ray flux than the observed IGRB

γ-ray neutrino

Problem2:SubstructuresinSpectrum

(Kalashev &Troitsky,1608.07421)

neutrino

Problem3:FewSourceCorrelation

γ-ray

10

Motivations:

•TeV – PeV neutrinoshavebeendetected

•WedonotknowtheoriginoftheTeV-PeV neutrinoandstructuresofitsspectrum

•highenergyneutrinoemissionsoftenassociatesγ-rayswhichisinconflictwithIGRBobservations

WeconsidertheN~30decayingDMscenario

CanweexplaintheTeV-PeV neutrinospectruminconsistencywiththeIGRBobservations?

Model

ℒ()* = ,-./ + 12∗4)56

-.78)

- = 9:!5 , . = #

<5

��

Wecanpredict2componentsinproducedneutrinospectrum

2branchesofdecaymodes:• DM->X+ν

• DM->2nS+ν

DM

S:darkfermion

n=15

multi-bodydecay!

DM

DM

ν X

ν S

SS

......

mode1:DM->X+ν

mode2:DM->2nS+ν

Eν

νFν

νFν

Eν

Wecanpredictbroad&line-likefeaturesinneutrinospectrum

featuresoftheneutrinospectrum

Result

pureDMfit:ν depositedenergy

mDM=4PeVBRline=0.034tDM=1.5e27s

pureDM:sourcespectrum

mDM=4PeVBRline=0.034tDM=1.5e27s

DM+astrophysicalhiddenaccelerator?

mDM=4PeVBRline=0.080tDM=3.4e27s

DM+ν fromtheprotonofEp~1017.5eV?

mDM=0.6PeVtDM=5.6e27s

OurN~30bodydecayingDMscenariocanexplaintheobservedspectrumwithoutsufferingfromIGRBconstraint

DM

ν

...

•WedonotknowtheoriginoftheTeV-PeV neutrinos@IceCube

•WeshouldbecarefulabouttheIGRBwhenwediscusstheoriginoftheneutrino

Conditions:

Choices:•astrophysicalordarkmatter(DM)orbothofthem?

Conclusion:

Summary: