Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

AMS-02 Antiprotons Reloaded

Rolf Kappl

Bethe Center for Theoretical Physics & Physikalisches Institut der UniversitätBonn

based on RK, Annika Reinert, Martin Wolfgang WinklerJCAP 10 (2015) 034, arXiv:1506.04145

Theory Seminar ULB Brussels,October 23th 2015

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Outline

Motivation

Cosmic Ray Propagation

Antiprotons Reloaded – Dark Matter Under Siege

Conclusions

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

AMS-02 – A Precision Experiment For Cosmic Rays

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Origin Of Cosmic Rays – Astrophysics At Work

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Primaries vs. Secondaries – Dark Matter?

• PrimariesSpallation−−−−−−→ Secondaries

• Dark matter annihilation

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Primaries vs. Secondaries – Dark Matter?

• PrimariesSpallation−−−−−−→ Secondaries

• Dark matter annihilation

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Primaries vs. Secondaries – Dark Matter?

• PrimariesSpallation−−−−−−→ Secondaries

• Dark matter annihilation

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Primaries vs. Secondaries – Dark Matter?

• PrimariesSpallation−−−−−−→ Secondaries

• Dark matter annihilation

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Primaries vs. Secondaries – Dark Matter?

• PrimariesSpallation−−−−−−→ Secondaries

• Dark matter annihilation

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Transport Of Cosmic Rays – Fokker-Planck

• Two-zone diffusion model

∇(−K ∇Ni + Vc Ni) + ∂E (btot Ni − KEE ∂ENi) + Γann Ni = qi

qi

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Transport Of Cosmic Rays – Fokker-Planck

• Two-zone diffusion model

∇(−K ∇Ni + Vc Ni) + ∂E (btot Ni − KEE ∂ENi) + Γann Ni = qi

qi

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Transport Of Cosmic Rays – Fokker-Planck

• Two-zone diffusion model

∇(−K ∇Ni + Vc Ni) + ∂E (btot Ni − KEE ∂ENi) + Γann Ni = qi

qi

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Transport Of Cosmic Rays – Fokker-Planck

• Two-zone diffusion model

∇(−K ∇Ni + Vc Ni) + ∂E (btot Ni − KEE ∂ENi) + Γann Ni = qi

qi

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Transport Of Cosmic Rays – Fokker-Planck

• Two-zone diffusion model

∇(−K ∇Ni + Vc Ni) + ∂E (btot Ni − KEE ∂ENi) + Γann Ni =

qi

qi

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Bethe’s Legacy – Boron As A Tracer

Bethe Center forTheoretical Physics Bethe, Phys.Rev. 55 (1939) 434-456• CNO cycle shows that boron is not produced in stars• Boron is produced by spallation of interstellar matter

• Injected boron qBPropagation−−−−−−−→ Measured boron at AMS-02

• Task:

qB = 4π∑

i∈{C,N,O,Ne,Mg,Si}

∫dT ′

dσdT

nISM Φi(T ′)

Φi(T ′)

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Bethe’s Legacy – Boron As A Tracer

Bethe Center forTheoretical Physics Bethe, Phys.Rev. 55 (1939) 434-456• CNO cycle shows that boron is not produced in stars• Boron is produced by spallation of interstellar matter

• Injected boron qBPropagation−−−−−−−→ Measured boron at AMS-02

• Task:

qB = 4π∑

i∈{C,N,O,Ne,Mg,Si}

∫dT ′

dσdT

nISM

Φi(T ′)

Φi(T ′)

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Cosmic Ray Primaries

10-1 1 101 102 10310-13

10-12

10-11

10-10

10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

1

101

102

T [GeV/n]

Φ iTOA·T2.7

[m-2sr

-1 s-1 (G

eV/n)1.7

]

Carbon

Oxygen·10-2

Nitrogen·10-4

Neon·10-6

Magnesium·10-8

Silicon·10-10

CREAM-IIHEAOPAMELA

ACE

• We considered C, N, O,Ne, Mg, Si as the maincontributions for boronproduction

• Fits to measured fluxes

Φi(T ) = A(

TT + b

)cT−γ

• Yet no AMS-02 data• Solar modulation

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Cosmic Ray Primaries

10-1 1 101 102 10310-13

10-12

10-11

10-10

10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

1

101

102

T [GeV/n]

Φ iTOA·T2.7

[m-2sr

-1 s-1 (G

eV/n)1.7

]

Carbon

Oxygen·10-2

Nitrogen·10-4

Neon·10-6

Magnesium·10-8

Silicon·10-10

CREAM-IIHEAOPAMELA

ACE

• We considered C, N, O,Ne, Mg, Si as the maincontributions for boronproduction

• Fits to measured fluxes

Φi(T ) = A(

TT + b

)cT−γ

• Yet no AMS-02 data• Solar modulation

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Interlude – Cosmic Rays In The Heliosphere

• Force field approximation for solar modulation

ΦTOA(T − Zφ) = (T − Zφ)2 + 2m(T − Zφ)

T 2 + 2mTΦIS(T )

• Force field parameter φ takes care of the solar activity

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Back To The Injection – Cross Sections Reloaded

• Source term:

qB = 4π∑

i∈{C,N,O,Ne,Mg,Si}

∫dT ′ dσdT nISMΦi(T

′)

• Parametrization from Webber et al., AJSS 144 (2003) 153• Large uncertainties, poor experimental data

10-1 1 10130

35

40

45

50

� [���]

σ(���

→�)[��]

���������� ��������

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Nuclear Physics Meets Astrophysics

• Source term qB for boron determined• Fokker-Planck equation solved with semi-analytical

approach in two dimensions Maurin et al., Astrophys.J. 555(2001) 585-596

• With the fit to the carbon flux⇒ B/C ratio computed(Secondary/Primary ratio)

• Scanned over a sample of random propagation parametersand kept only configurations which passed χ2 test

Propagation parameters fixed with highest precision!

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

B/C Before AMS-02

• Best data before AMS-02 from the PAMELA experimentAdriani et al., Astrophys. J. 791 (2014), 93

• Clear trend but still large uncertainties

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

B/C In The AMS-02 Precision Era

• Low experimental errors and data up to high rigidities• Still preliminary data⇒ Data quality will further increase

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

p̄/p Ratio With Old Propagation Parameters

• p̄/p ratio computed with outdated (unknown?) propagationparameters

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Protons And Helium – Primaries Reloaded

• Source term for p̄ production:

qp̄ = 4π∑

i∈{H,He}

∫dT ′

dσdT

nISM Φi(T ′)

1 101 102 103 104 105

103

104

T [GeV/n]

Φ iTOA·T2.7

[m-2sr

-1 s-1 (G

eV/n)1.7

] Proton

Helium

CREAM

AMS-02

• Fits to measured fluxes withspectral break

Φi(T ) =(

TT + b

)c ∑k

AkT−γk

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

New p̄ Production Cross Sections

• Source term for p̄ production:

qp̄ = 4π∑

i∈{H,He}

∫dT ′ dσdT nISMΦi(T

′)

0.0 0.1 0.2 0.3 0.4 0.5

10-4

10-3

10-2

10-1

1

xR

f pp

®p

o@m

bGe

V2

D

pT = 1.3 GeV

pT = 0.9 GeV

pT = 0.5 GeV

pT = 0.1 GeVNA49 Data, Fit • New results from NA49

experiment with hugephase space coverageAnticic et al., Eur. Phys. J.C65 (2010) 9

• Tracking of uncertainties,hyperon ’feed-down’effects, isospin effects, ...RK and Winkler, JCAP 09(2014) 051

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

p̄/p Ratio With New Propagation Parameters

• p̄/p ratio computed with new cross sections• New propagation parameters derived from boron⇒ Good

agreement for antiprotons• No need for antiprotons from dark matter annihilation⇒

Good probe to constrain dark matter models

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Outlook – Positrons, Better Cross Section Data, . . .

1 101 1020

5

10

15

20

25

30

T [GeV]

ΦTOA·T3 [

m-2 s

r-1s-1

GeV

2 ]propagation uncertaintiese+ best fit in sampleAMS-02 e+ data

• Data on positrons can be used to further constrainpropagation parameters

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Outlook – Positrons, Better Cross Section Data, . . .

10-1 1 10130

35

40

45

50

� [���]

σ(���→�)

[��]

���������� ��������

• New cross section measurements would dramaticallydecrease the uncertainty

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Outlook – Positrons, Better Cross Section Data, . . .

10-1 1 10130

35

40

45

50

� [���]

σ(���→�)

[��]

���������� ��������

• New cross section measurements would dramaticallydecrease the uncertainty

Motivation Cosmic Ray Propagation Antiprotons Reloaded – Dark Matter Under Siege Conclusions

Conclusions

• With AMS-02 the precision era for indirect dark matterdetection started

• We estimated the antiproton background with very highprecision

• The new antiproton data together with our backgroundcalculation will be a perfect probe for dark matter models

Thank you for your attention!

MotivationCosmic Ray PropagationAntiprotons Reloaded – Dark Matter Under SiegeConclusions