Galactic cosmic rays (GCR) and dark matter indirect detection Group: DARK (AMS-CREAM-LSST) Research activity: phenomenology 1. Introduction : GCRs, dark matter indirect detection 2. Recent results and interpretation 3. Research activities at LPSC and 2-year goals - Solar modulation - GCR interpretation - Dark matter indirect detection David Maurin CS LPSC (LPSC) 16 Dec. 2016 dmaurin@lpsc.in2p3.fr
1. Introduction: GCR propagation and standard astrophysics (plasma physics) (nuclear physics) Galactic Tycho's SNR wind p, He, C R ☼ ~ 8 kpc p, d, e + , B (astrophysics + particle physics)
1. Introduction: GCR propagation and dark matter (plasma physics) (nuclear physics) Galactic Tycho's SNR wind p, He, C R ☼ ~ 8 kpc p, d, e + p, d, e + , B (astrophysics + particle physics) Indirect detection Direct detection Universe (after Planck) Milky-Way dark matter halo Dark ● 68.3 % dark energy Standard ● ~ spherical halo ● 26.8 % dark matter matter matter ● radius ~300 kpc ● 4.9 % ordinary matter Production (colliders)
1. Introduction: dark matter indirect detection in γ -rays Dense (~ ∫ ρ 2 ) – Close (1/d 2 ) – No astrophysical background In the Milky-Way Galactic centre (diffuse emission) Dwarf spheroidal galaxies 8 kpc ~300 kpc ΔΩ Dark micro-halos Outside the Galaxy Milky-Way clusters Extragalactic diffuse emission
1. Introduction: from lowest to highest energies Impact of Solar Galactic modulation AMS ISS- CREAM Extragalactic → CR sources and transport? → Origin of spectral features, composition, anisotropy? → Transition galactic/extragalactic?
1. Introduction: Galactic cosmic rays (~10 8 -10 15 eV) Elemental composition Beringer et al., PRD 86, 010001 (2012) p, He, diffuse γ -rays, antiprotons, e - , and e + Beischer et al. (2009) e - p e + He γ _ p → Transport parameters → Dark matter indirect detection → Acceleration mechanisms: injection, efficiency, ... → Transport: diffusion, convection, energy gain and losses... → CR anisotropy δ <10 -3 ( ≠ E and species)
1. Introduction : GCRs, dark matter indirect detection 2. Recent results and interpretation 3. Research activities at LPSC and 2-year goals - Solar modulation - GCR interpretation - Dark matter indirect detection
2. Recent results: positron fraction and antiprotons Aguilar et al., PRL 110, 1102 (2013) Accardo et al., PRL 113, 121101 (2014) Kappl et al., JCAP 09, 023 (2015) Solar modulation effect Positron fraction, e - , e + and e - +e + spectra used to test astrophysical and/or dark matter hypothesis Antiprotons ● Contribution from local SNRs/pulsars? → e.g., Delahaye et al., A&A 524, A51 (2010) → Seems consistent with astrophysics only ● Dark matter hypothesis? → e.g., Boudaud et al., A&A 575, 67 (2015) [N.B.: no boost, Lavalle et al., A&A 479, 427 (2008)] N.B.: see also e- and e+ in Aguilar et al., PRL 113, 121102 (2014)
2. Recent results: p, He, and B/C Aguilar et al., PRL 114, 171103 (2015) Aguilar et al., PRL 115, 211101 (2015) Spectral break Different slopes at ~ 350 GV γ p − γ He >0.1 for p and He
2. Recent results: p, He, and B/C Aguilar et al., PRL 114, 171103 (2015) Aguilar et al., PRL 115, 211101 (2015) Spectral break Different slopes at ~ 350 GV γ p − γ He >0.1 for p and He Aguilar et al., PRL 117, 231102 (2016) Asymptotically Kolmogorov → Need to explore slope for other primary (C, O) and secondary (Li, Be, B) species
2. Recent results: possible interpretations N.B.: Different diffusion coefficient in the disk and halo [self-generated turbulence vs pre-existing turbulence, or different damping mechanisms in different medium?] Aloisio et al., A&A 583, A95 (2015) Many others explanations: ● Secondary production at source (for positrons), single or multiple local sources, ... ● Reacceleration, spiral arm structure, time and spatial discretness...
1. Introduction : GCRs, dark matter indirect detection 2. Recent results and interpretation 3. Research activities at LPSC and 2-year goals - Solar modulation - GCR interpretation - Dark matter indirect detection
3. Research activities at LSPC: GCR tools and studies Time-independent Galactic 4) Top-of-Atmosphere to sea level Time-dependent Cosmic 1) Transport in the Galaxy Rays ISS ( h~400 km) 3) Earth magnetic shield Atm. ~ 0 g cm -2 size ~ 30 kpc <t> ~ 20 Myr size ~ 10 4 km 2) Transport in Solar cavity size ~ 100 AU <t> ~ few years Balloon ( h~40 km) Atm. ~ 5 g cm -2 x 10 7 x 10 5 Neutron monitor ( h<2 km) Atm. ~ 600-1000 g cm -2
3. Research activities at LSPC: CR database and φ (t) Time-independent Galactic 4) Top-of-Atmosphere to sea level Time-dependent Cosmic 1) Transport in the Galaxy Rays ISS ( h~400 km) 3) Earth magnetic shield Atm. ~ 0 g cm -2 size ~ 30 kpc <t> ~ 20 Myr size ~ 10 4 km 2) Transport in Solar cavity size ~ 100 AU <t> ~ few years Balloon ( h~40 km) Atm. ~ 5 g cm -2 x 10 7 x 10 5 CR database and φ time series (https://lpsc.in2p3.fr/crdb/): ~90000 requests from 90 countries Support F. Melot (service informatique) Neutron monitor ( h<2 km) A. Ghelfi (PhD thesis) Atm. ~ 600-1000 g cm -2
3. Research activities at LSPC: Cosmic-Ray DataBase Time-independent Galactic 4) Top-of-Atmosphere to sea level Time-dependent Cosmic 1) Transport in the Galaxy Rays ISS ( h~400 km) 3) Earth magnetic shield Atm. ~ 0 g cm -2 size ~ 30 kpc <t> ~ 20 Myr size ~ 10 4 km 2) Transport in Solar cavity size ~ 100 AU <t> ~ few years Balloon ( h~40 km) Atm. ~ 5 g cm -2 x 10 7 x 10 5 Public codes ● USINE, a propagation code ● GreAT (http://lpsc.in2p3.fr/great), an MCMC engine Neutron monitor ( h<2 km) A. Ghelfi, PhD thesis AMS-02 data interpretation Atm. ~ 600-1000 g cm -2 - Origin of p/He anomaly - Two-halo propagation scenario - Impact of nuclear uncertainties - ... N. Tomassetti (post-doc) Tomassetti (post-doc)
3. Research activities at LSPC: γ -rays best targets and CTA CLUMPY public code (http://lpsc.in2p3.fr/clumpy/) V. Bonnivard (PhD thesis), C. Combet, M. Hütten (PhD student@DESY) Triaxial dark matter halo Dwarf spheroidal + galaxies Dark micro-halos Angular resolution = 0.12° (HEALPix Nside=512) → Best analysis for dwarf spheroidal ranking (crucial for Fermi-LAT constraints) → Ranking and stacking strategy for galaxy clusters (Fermi-LAT and CTA) → Dark clump sensitivity for CTA
3. Research activities at LPSC: evolution and goals N.B.: co-supervised theses (within the group) analysis/phenomenology ~2009-2012 2013-2016 2017-2018 Stages M2 ● A. Coulon (2011) : 50% ● V. Bonnivard (2013) : 50% ● M. Vauthrin (2012) : 50% ● A. Ghelfi (2013) : 50% ● V. Bonnivard (2013-16) : 70% Theses ● A. Putze (2006-09) : 70% ● A. Ghelfi (2013-16) : 50% ● B. Coste (2009-12) : 30% ● S. Aupetit (2015-2018) : 50% ● S. Aupetit (2015-18) : 50% Post-Docs ● N. Tomassetti (2013-2016) : 50% Staff ● D. Maurin (CR) : 100% ● D. Maurin (CR) : 100% ● D. Maurin (CR) : 100% ● L. Derome (Prof.) : 20% ● C. Combet (CR) : 20% ● C. Combet (CR) : 20% ● J. Bregeon (visitor) : 10% Pipex index GCR: 5 pubs (260 citations) GCR: 13 pubs (105 citations) γ -rays: 6 pubs (166 citations) γ -rays: 7 pubs (95 citations) + UK/US/Germany/France collaborations
3. Research activities at LPSC: evolution and goals N.B.: co-supervised theses (within the group) analysis/phenomenology ~2009-2012 2013-2016 2017-2018 Stages M2 ● A. Coulon (2011) : 50% ● V. Bonnivard (2013) : 50% ● M. Vauthrin (2012) : 50% ● A. Ghelfi (2013) : 50% ● V. Bonnivard (2013-16) : 70% Theses ● A. Putze (2006-09) : 70% ● A. Ghelfi (2013-16) : 50% ● B. Coste (2009-12) : 30% ● S. Aupetit (2015-2018) : 50% ● S. Aupetit (2015-18) : 50% Post-Docs ● N. Tomassetti (2013-2016) : 50% Staff ● D. Maurin (CR) : 100% ● D. Maurin (CR) : 100% ● D. Maurin (CR) : 100% ● L. Derome (Prof.) : 20% ● C. Combet (CR) : 20% ● C. Combet (CR) : 20% ● J. Bregeon (visitor) : 10% Pipex index GCR: 5 pubs (260 citations) GCR: 13 pubs (105 citations) γ -rays: 6 pubs (166 citations) γ -rays: 7 pubs (95 citations) + UK/US/Germany/France collaborations Solar modulation S. Aupetit (PhD student) → Better Solar modulation model + time-dependent AMS data GCR interpretation → B/C, Li, pbar, etc.: collaboration with LAPTh DM and γ -rays → Extragalactic contribution (M. Hütten 3 months visit)
GCR propagation: from microphysics to diffusion [Adapted from R. Tautz (CRISM 2014)] ● Physics problem: motion in a turbulent field ● Ansatz: diffusion equation Analytical calculation Numerical simulations - Mean free path Reality: resonant wave-particle interaction with stochastic motion... turbulence model requires: Pitch angle µ =cos( v , B 0 ) ● Energy spectrum (diff.eq. for wave!): W k -s ● Geometry - Fokker-Planck coefficient ● Dynamical behaviour Taylor-Green-Kubo formula - Instabilities - Damped waved - Equation of motion (Lorentz) - Intermittency Unknown v x,y , unknown position in δ B x,y Diffusion in MHD → Can only be solved in ideal situations turbulence ● Quasi-Linear Theory ( δ B ≪ B): QLT ● 2 nd order QLT: SOQLT ● Non-linear guiding centre: NLGC
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