AMS-02 Antiprotons Reloaded Rolf Kappl Bethe Center for Theoretical Physics & Physikalisches Institut der Universität Bonn based on RK, Annika Reinert, Martin Wolfgang Winkler JCAP 10 (2015) 034, arxiv:1506.04145 Theory Seminar ULB Brussels, October 23th 2015
Outline 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
Primaries vs. Secondaries Dark Matter? Spallation Primaries Secondaries Dark matter annihilation
Primaries vs. Secondaries Dark Matter? Spallation Primaries Secondaries Dark matter annihilation
Primaries vs. Secondaries Dark Matter? Spallation Primaries Secondaries Dark matter annihilation
Primaries vs. Secondaries Dark Matter? Spallation Primaries Secondaries Dark matter annihilation
Primaries vs. Secondaries Dark Matter? Spallation Primaries Secondaries Dark matter annihilation
Transport Of Cosmic Rays Fokker-Planck Two-zone diffusion model ( K N i + V c N i ) + E (b tot N i K EE E N i ) + Γ ann N i = q i
Transport Of Cosmic Rays Fokker-Planck Two-zone diffusion model ( K N i + V c N i ) + E (b tot N i K EE E N i ) + Γ ann N i = q i
Transport Of Cosmic Rays Fokker-Planck Two-zone diffusion model ( K N i + V c N i ) + E (b tot N i K EE E N i ) + Γ ann N i = q i
Transport Of Cosmic Rays Fokker-Planck Two-zone diffusion model ( K N i + V c N i ) + E (b tot N i K EE E N i ) + Γ ann N i = q i
Transport Of Cosmic Rays Fokker-Planck Two-zone diffusion model ( K N i + V c N i ) + E (b tot N i K EE E N i ) + Γ ann N i = q i
Bethe s Legacy Boron As A Tracer Bethe Center for Theoretical 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 Propagation Injected boron q B Measured boron at AMS-02 Task: q B = 4π i {C,N,O,Ne,Mg,Si} dt dσ dt n ISM Φ i (T )
Bethe s Legacy Boron As A Tracer Bethe Center for Theoretical 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 Propagation Injected boron q B Measured boron at AMS-02 Task: q B = 4π i {C,N,O,Ne,Mg,Si} dt dσ dt n ISM Φ i (T )
Cosmic Ray Primaries [ m -2 sr -1 s -1 (GeV/n) 1.7 ] 10 2 10 1 1 10-1 10-2 10-3 10-4 10-5 10-6 Carbon Oxygen 10-2 Nitrogen 10-4 Neon 10-6 We considered C, N, O, Ne, Mg, Si as the main contributions for boron production Fits to measured fluxes ( ) T c Φ i (T ) = A T γ T + b Φ i TOA T 2.7 10-7 10-8 10-9 Magnesium 10-8 Yet no AMS-02 data Solar modulation 10-10 Silicon 10-10 10-11 ACE PAMELA 10-12 HEAO CREAM-II 10-13 10-1 1 10 1 10 2 10 3 T [GeV/n]
Cosmic Ray Primaries [ m -2 sr -1 s -1 (GeV/n) 1.7 ] 10 2 10 1 1 10-1 10-2 10-3 10-4 10-5 10-6 Carbon Oxygen 10-2 Nitrogen 10-4 Neon 10-6 We considered C, N, O, Ne, Mg, Si as the main contributions for boron production Fits to measured fluxes ( ) T c Φ i (T ) = A T γ T + b Φ i TOA T 2.7 10-7 10-8 10-9 Magnesium 10-8 Yet no AMS-02 data Solar modulation 10-10 Silicon 10-10 10-11 ACE PAMELA 10-12 HEAO CREAM-II 10-13 10-1 1 10 1 10 2 10 3 T [GeV/n]
Interlude Cosmic Rays In The Heliosphere Force field approximation for solar modulation Φ TOA (T Z φ) = (T Z φ)2 + 2m(T Z φ) T 2 Φ IS (T ) + 2mT Force field parameter φ takes care of the solar activity
Back To The Injection Cross Sections Reloaded Source term: q B = 4π i {C,N,O,Ne,Mg,Si} dt dσ dt n ISMΦ i (T ) Parametrization from Webber et al., AJSS 144 (2003) 153 Large uncertainties, poor experimental data 50 σ ( ) [ ] 45 40 35 30 10-1 1 10 1 [ ]
Nuclear Physics Meets Astrophysics Source term q B 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 parameters and kept only configurations which passed χ 2 test Propagation parameters fixed with highest precision!
B/C Before AMS-02 Best data before AMS-02 from the PAMELA experiment Adriani et al., Astrophys. J. 791 (2014), 93 Clear trend but still large uncertainties
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
p/p Ratio With Old Propagation Parameters p/p ratio computed with outdated (unknown?) propagation parameters
Protons And Helium Primaries Reloaded Source term for p production: q p = 4π dt dσ dt n ISM Φ i (T ) i {H,He} Φ i TOA T 2.7 [ m -2 sr -1 s -1 (GeV/n) 1.7 ] 10 4 10 3 Proton Helium AMS-02 Fits to measured fluxes with spectral break Φ i (T ) = ( ) T c A k T γ k T + b k CREAM 1 10 1 10 2 10 3 10 4 10 5 T [GeV/n]
New p Production Cross Sections Source term for p production: q p = 4π dt i {H,He} dσ dt n ISMΦ i (T ) mb GeV 2 o f pp p 1 10 1 10 2 10 3 10 4 0.0 0.1 0.2 0.3 0.4 0.5 x R NA49 Data, Fit p T p T p T p T 0.1 GeV 0.5 GeV 0.9 GeV 1.3 GeV New results from NA49 experiment with huge phase space coverage Anticic et al., Eur. Phys. J. C65 (2010) 9 Tracking of uncertainties, hyperon feed-down effects, isospin effects,... RK and Winkler, JCAP 09 (2014) 051
p/p Ratio With New Propagation Parameters p/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
Outlook Positrons, Better Cross Section Data,... 30 Φ TOA T 3 [ m -2 sr -1 s -1 GeV 2 ] 25 20 15 10 5 AMS-02 e + data e + best fit in sample propagation uncertainties 0 1 10 1 10 2 T [GeV] Data on positrons can be used to further constrain propagation parameters
Outlook Positrons, Better Cross Section Data,... 50 σ ( ) [ ] 45 40 35 30 10 1 101-1 [ ] New cross section measurements would dramatically decrease the uncertainty
Outlook Positrons, Better Cross Section Data,... 50 σ ( ) [ ] 45 40 35 30 10 1 101-1 [ ] New cross section measurements would dramatically decrease the uncertainty
Conclusions With AMS-02 the precision era for indirect dark matter detection started We estimated the antiproton background with very high precision The new antiproton data together with our background calculation will be a perfect probe for dark matter models Thank you for your attention!