PoS(EDSU2018)012 http://pos.sissa.it/ ∗ [email protected] Speaker. I present of summary of the currentastrophysical status data. of I searches also for discuss signals the from prospects dark for matter such interactions searches in in the next few years. ∗ Copyright owned by the author(s) under the terms of the Creative Commons c Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). 2nd World Summit: Exploring the Dark25-29 Side June, of 2018 the - Universe EDSU2018 University of Antilles, Pointe-à-Pitre, Guadeloupe, France Kavli Institute for Particle Astrophysics andStanford Cosmology, University, SLAC Stanford, National CA Accelerator 94305, Laboratory, USA E-mail: Eric Charles Indirect Searches: Status and Prospects PoS(EDSU2018)012 ) ◦ ( Eric Charles 3 5 5 ∼ . . 10 0 0 > < < up to -ray signals correlated γ ) Angular Extent 5 23 19 − ]). No particle in the Standard 8 10 10 19 18 cm eV. Both types of candidates could 2 × × 10 10 9 × × ]), precision measurements of the cos- ]), all point to a substantial fraction of - Isotropic to 5 to 3 2 GeV 5 to 10 22 17 10 10 10 − up to 1 × × factor ( J 1 4 ]), observations of the primordial abundances of heavy ]), and does not have large scattering cross sections with 6 4 10 4 , , 10 3 × 3 5 > Summary table of DM search targets. > ]) summarizes the targets for WIMP searches, including the as- 9 ] and references therein). ray point sources; on the other hand, extracting a isotropic signal 6 Table 1: γ ]) or Standard Model particles (see e.g., [ 7 ]) and cluster dynamics (see e.g., [ 1 Target Distance (kpc) (taken from Ref. [ 1 Dark satellites up to 300 up to 3 Galaxy Clusters Cosmological DM Galactic center / halo 8.5 3 Two favored candidates for the DM particle are weakly interactive massive particles (WIMPs, Indirect dectection WIMP searches consist of looking for anomolous Tab. The observational evidence implies that DM is non-relativistic (i.e., “cold”) during the forma- Overwhelming evidence indicates that the matter in the Universe can not only consist of par- Known Milky Way satellites 25 to 300 3 trophysical “J-factor”, which isinteraction proportional rate. to The the differences between expected themodifications signal targets in magnitude are the pronounced for search enough techniques. as toinated warrant given For Milky significant DM example, Way searches satellites targeting arewhen known very dark-matter creating similar dom- catalogs to of blindfrom searches DM for halos point-like of emissionGalactic at performed foreground cosmological emission distances and requires the very contributions of detailed unresolved modeling sources. of both the with masses in the GeV topoorly constrained TeV range) and could and range axions/ anywhere axion-like from particles 10 (ALPs, whose masses very mic microwave background (see e.g., [ either itself (see e.g., [ Model meets the requirements. Weof have the no fundamental other nature solid of experimental DM. or theoretical understanding be detected via signatures in astrophysical data (a.k.a., “indirect-detection” searches). 2. Status of Current Indirect Detection Dark Matter Searchs with regions or astrophysical structuresare known identified to from host a large combination of amounts analysis of of DM. kinematic The data and analysis study targets of numerical simulations. isotopes produced by Big Bang nucleosynthesis (see e.g., [ tion of large-scale structure (see e.g., [ ticles in the Standard Modelcurves (see of e.g., particle [ physics. In particular, measurements of galactic rotation Indirect Dark Matter Searches 1. Introduction the Universe’s energy density being inStandard a Model form particles. of matter Numerical that simulations doession; of not large-scale in interact structure fact, signifcantly also such with support simulations the thiswith require conclu- observations (see non-relativistic e.g., dark [ matter (DM) in order to be consistent PoS(EDSU2018)012 = . χ N m rays for γ Eric Charles ) to be below 2 -ray data. Ad- γ (red shaded regions). 2 500 GeV. rays produced in very dense ∼ γ χ . 100 GeV) and from the expected 1 m & χ m ( 1 TeV for the LMC). 2 . χ m factors than searches targeting other objects. Addition- J value targets. J ]. 9 rays from axion or ALP decays produced in neutron interiors lead to the γ 10 TeV for the Galactic center, ] made a detailed analysis of the sensitivity considerations for DM WIMP searches and eV. It should be noted that these limits not only depend on the axion and ALP coupling 9 . 2 − χ are background limited atcombined lower analysis of energies, dSphs and the cross-over signal point limited comes at at higher energies. For the 100 GeV). power in the spectral domain, but are still systematics limited at low energies (e.g., center, large Galaxy clusters, and them LMC are systematics limited up to high energies (e.g., ]. The limits constrain the QCD axion mass (black line and yellow band in Fig. 10 Ref. [ The current limits on the ALP parameters are summarized in Fig. Axions and ALPs can produced signatures in astrophysical data because of their couplings to In short, prospects for the most notable improvements to our senstivitty come from additional Furthermore, searches targeting the dSphs have smaller modeling uncertainties and more ro- Currently, the deepest limits come from searches targeting the dwarf spheroidal Milky Way Because of differences in the datasets, DM profiles, and background modeling, these results × 10 3. Searches targeting relatively small objects at high Galactic latitudes, in particular the dSphs, 2. Searches for spectral lines from the Galactic halo benefit from additional discriminating 1. Searches targeting objects with substantial astrophysical backgrounds, such as the Galactic rays is significanlty reduced. This could allow us to observe 9 . environments or at very great distances. 3. Prospects for upcoming Indirect Detection Dark Matter Searchs 7 to photons but also on the axion and ALP production through nucleon-nucleon Bremsstrahlung. ditionally, ALP-photon mixing can provide aγ mechanism by which the attenuation of high-energy photons. ALP-photon interactions can produce charateristic spectral features in data for searches targeting the dSphs for higher DM masses bust determinations of the astrophysical the Galactic center as a possible DM signal. derived these broad conclusions: discovery of additional high ally these searches haveOverall among these the considerations suggest best that, sensitivitiestinue looking to forward, across have searches much the targeting best of the sensitivity. dSphs This the will can relevant con- clearly energy be seen band. inThe Fig. search for sattelite galaxies, and these limits are in tension with results that interpret an excess of limits labeled “ALPs from NS” (gray hatched region, assuming the model-dependent factor should be taken as representative and absolutetails comparisons about should be the interpreted scenarios with considered caution. (e.g.,in De- the Table 2 DM of distribution) Ref. for [ each of the targets are provided Indirect Dark Matter Searches 1) [ PoS(EDSU2018)012 0 0 1 Eric Charles 1 ] and references - 0 1 17 , 16 2 - , 4 0 1 15 , 10 14 3 - ,

0 QCD axion QCD 1 13 , 12 4 - 0 1 ALPS IIALPS II IAXOIAXO (Steigman+ 2012) 3 5 - ) 0 V 1 10

e

( ADMX -ray opacity is shown in light blue. The parameter

a γ Thermal Relic Cross Section 6 - m 3 0 1 -ray opacity are shown in blue. Sensitivity estimates for γ ]) regions. Limits from other experiments are shown in red. 7 [GeV] - 10 Globular clusters 0

1 χ

H.E.S.S. H.E.S.S. 2 m Daylan+ (2014) Gordon & Macias (2013) Calore+ (2014) Abazajian+ (2014) 8 - 10 0 1 T A L

i 9 - m r 0 e 1 NGC 1275 F tt ss 0 rr 1 uu - bb

0 yy 1 aa 1 rr -- dSphs (proj. 15 yrs 60Isotropic: dpshs) (Proj. 15 years,APS: syst/10) (Proj. 15 years) Clusters: (P8: 15 years) Unid. Sat.: (Proj. 15MW years) Center: (Proj. 15 years 1% syst) SN1987ASN1987A γγ 10

1 b ¯

1 X-rays Hydra A Hydra X-rays - b 0 1 Comparison of projected LAT limits for 15 years of data for the search methods described in. Current status of the limits imposed on the ALP parameter space by different experiments and ]) and gray hatched (neutron [ 3 1 2 0 28 24 25 26 27 22 23 1 1 1 1

- - - -

11 0 0 0 0 − − − − − − −

1 1 1 1

i h

γ a −

V e G ( )

10 g 10 10 10 10 10 10 1

−

[cm σv ] s

1 3 therein. Figure 2: targets. Limits derivedcluster with [ LAT observations areThe shown parameter as space dark where ALPs red could (NGC 1275 explain a in low the galaxy Figure 1: Favored contours for several Galactic center analyses are also included for comparison. space where ALPs could explain hints for a low future laboratory experiments are shown inbelow green. the The dashed QCD line axion line could is account shown for in all yellow. ALP the parameters DM. See also Refs. [ Indirect Dark Matter Searches PoS(EDSU2018)012 J. C. A. P. Eric Charles Ap. J. (1980) ArXiv e-prints (2013) , A.A.P. (2015) , A.A.P. (2014) Journal of Instrumentation. , Helv.Phys.Acta (1933) 4 Phys. Rev. D (2016) Phys. Rev. D (2013) Rotational properties of 21 SC galaxies with a large range astro-ph/0301505 (2003) J. C. A. P. (2015) Phys. Rev. Lett. (2016) Ap. J. (2004) First lower limits on the photon-axion-like particle coupling from Constraints on axions and axionlike particles from Fermi Large Dark matter evidence, particle physics candidates and detection Phys. Rev. D (2013) Sensitivity of the Cherenkov Telescope Array to the detection of axion-like Constraints on axionlike particles with H.E.S.S. from the irregularity of the PKS Direct constraints on the dark matter self-interaction cross-section from the Search for Spectral Irregularities due to Photon-Axionlike-Particle Oscillations First results from the LUX dark matter experiment at the Sanford Underground Planck 2013 results. XVI. Cosmological parameters Planck 2015 results. XIII. Cosmological parameters Phys. Rev. Lett. (2014) Sensitivity projections for dark matter searches with the Fermi Large Area Telescope Revisiting the SN1987A gamma-ray limit on ultralight axion-like particles Any light particle search II – Technical Design Report Dark Sectors and New, Light, Weakly-Coupled Particles TASI lectures on dark matter Die Rotverschiebung von extragalaktischen Nebeln Annalen der Physik (2012) (2013) Research Facility With the Fermi Large Area Telescope Physics Reports. (2016) Area Telescope observations of neutron stars 2155-304 energy spectrum merging 1E0657-56 methods (2015) very high energy gamma-ray observations particles at high gamma-ray opacities of luminosities and radii, from NGC 4605 /R = 4kpc/ to UGC 2885 /R = 122 kpc/ [8] D. S. Akerib et al. [9] E. Charles et al. [1] V. Rubin, N. Thonnard and W.K. Ford Jr. [7] M. Markevitch et al. [2] F. Zwicky [3] P. A. R. Ade et al. [6] C. S. Freck and S. D. M. White [4] P. A. R. Ade et al. [5] K. A. Olive [12] R. Bähre et al. [13] A. Payez et al. [10] B. Berenji, J. Gaskins, M. Meyer [11] M. Ajello, M. et al. Indirect Dark Matter Searches References [14] A. Abramowski et al. [15] M. Meyer, D. Horns and M. Raue [16] M. Meyer and J. Conrad [17] R. Essig et al.