TWO ASPECTS OF SIDM Michel H.G. Tytgat Universit Libre de Bruxelles - PowerPoint PPT Presentation

TWO ASPECTS OF SIDM Michel H.G. Tytgat Université Libre de Bruxelles Belgium GGI, Florence, September 11th 2018

SIDM MOTIVATION DIRECT DETECTION IS TESTING FI Direct detection is testing Freeze-in Th. Hambye, M.T., J. Vandecasteele & L. Vanderheyden (2018) (The Four Basic Ways of Creating Dark Matter Through a Portal) X. Chu, Th. Hambye & M.T (2012) SIDM + NS → BH Non-primordial solar mass black holes C. Kouvaris, P. Tinyakov, M.T. (2018)

WHY SIDM ? core or cusp? to-big-to-fail ? missing satellites ? CDM only simulation

SIDM may alleviate the small-scale problems core/cusp Spergel & Steinhardt (2000),… too-big-to-fail Vogelsberger, Zavala & Loeb (2012),… diversity* Hamada, Kaplinghat, Pace & Yu (2016),… collisions ⟶ thermalized DM ⟶ core instead of cusp m ∼ cm 2 ≡ barn σ i.e. seemingly hadronic g GeV but more generally light mediator

DIVERSITY PROBLEM There is a diversity problem unexplained by CDM + BARYONS simulations (mostly dwarf galaxies) all same v max Oman et al , arXiv:1504.01437

DIVERSITY PROBLEM σ /m ∼ cm 2 Diversity problem solved/alleviated with g Hamada, Kaplinghat, Pace & Yu, arXiv:1611.02716

HIDDEN SECTOR Patt & Wilczek (2006) HS HS SM

THE SM PORTALS Patt & Wilczek (2006) renormalizable SM singlet interactions operators (i.e. dimensionless couplings) ∆ L ⊃ y ¯ L ˜ L ˜ ¯ Sterile neutrino HN H Dodelson & Widrow (1994) … ∆ L ⊃ ✏ B µ ν X µ ν B µ ν Kinetic mixing Holdom (1986) … ∆ L ⊃ λ S 2 H † H H † H Higgs portal Linked to EWSB? This one is also Lorentz invariant Silveira & Zee (1985) Veltman & Ynderain (1989) …

PART I DIRECT DETECTION IS TESTING FREEZE-IN Direct detection is testing Freeze-in Th. Hambye, M.T., J. Vandecasteele & L. Vanderheyden (2018)

KINETIC MIXING hidden charged χ γ 0 dark photon HS HS SM ( also ) Z α 0 gauge interaction in HS χ χ stable ~ SM electron m χ p ↵ 0 / ↵ χ suppressed coupling to SM  = ✏ only 4 parameters m γ 0

FIMP THROUGH KINETIC MIXING some heavy particles X ν HS B µ HS SM Holdom (1986) is naturally tiny ! κ DM feebly coupled to SM Feebly Interacting Massive Particle or FIMP Chu, Hambye, M.T. ‘12

ABUNDANCE FROM FREEZE-IN HS feebly coupled ~ no thermal equilibrium abundance could built up from slow processes ¯ f χ χ γ 0 Z p ↵ 0 / ↵ ∝  = ✏ f ¯ ¯ χ χ FREEZE-IN * Mc Donald ’02; Hall, Jedamzik & March-Russell ’10; Chu, Hambye, M.T. ‘12

ABUNDANCE FROM FREEZE-IN 10 � 5 � Y ∞ ⇡ h σ v i n SM � � H � T FI 10 � 7 Y = n/s Y ∼ Γ × τ U 10 � 9 10 � 11 Freeze-in at T FI ≈ max( m DM , m SM ) 10 � 13 0.01 0.1 1 10 100 x = m/T

ABUNDANCE FROM FREEZE-IN m γ 0 = 0 Y ∝ κ 2 /m DM Y ∝ κ 2 /m DM Y ∝ κ 2 /m e Z decay Y ∝ κ 2 Chu, Hambye, M.T. ‘12

ABUNDANCE FROM FREEZE-OUT DM + DM − → SM + SM Γ = σ v n DM ABUNDANCE FROM FREEZE-IN SM + SM − → DM + DM Γ = σ v n SM

FREEZE-IN vs FREEZE-OUT HS thermalizes Ω dm freeze-in freeze-out regime regime 0.23 O(1) 10 -11 κ

4 BASIC WAYS TO CREATE DM THROUGH A PORTAL II : reannihilation III : freeze-out in hidden sector (secluded DM) IV : usual I : freeze-in freeze-out Chu, Hambye, M.T. ‘12

DIRECT DETECTION TEST OF FREEZE-IN HOW TO TEST FREEZE-IN ? DIRE p ↵ 0 / ↵ = (10 � 11 ) cosmic abundance  = ✏ DM SM direct detection DM SM

PRODUCTION THROUGH S-CHANNEL ¯ f χ γ 0 f ¯ χ s-channel determines relic abundance very small cross section Rutherford (1911)

RUTHERFORD SCATTERING - DIRECT DETECTION recoil energy N E R χ γ 0 in keV range t-channel N χ v ~ 200 km/s (halo DM) m N κ 2 α 2 Z 2 d σ 1 ∝ ∼ (2 m N E R + m 2 E 2 γ 0 ) 2 dE R R large enhancement if m γ 0 . 40 MeV

DIRECT DETECTiON IS TESTING FREEZE IN n.b.: XENON1T 2018 Not the same spectrum as a WIMP, Must recasti the direct detection constraints 10 − 10 κ Freeze-in 10 − 11 10 1 10 2 10 3 m χ (GeV) first direct detection test of a FI scenario Hambye, M.T., Vandecasteele, Vanderheyden ‘18

RECASTING DIRECT DETECTION LIMITS heavy mediator light mediator XENON1T 2018 10 − 10 κ Freeze-in 10 − 11 10 1 10 2 10 3 m χ (GeV) ( m dm , σ dm ,n ) ( m χ , κ ) We minimized the differential rate « quadratic distance » XENON1T efficiency

DIRECT DETECTiON IS TESTING FREEZE IN Hambye, M.T., Vandecasteele, Vanderheyden ‘18

SIDM : RUTHERFORD SCATTERING AGAIN χ ¯ χ γ 0 t-channel v dwarf ∼ 10 km / s ¯ χ χ 4 α 0 2 m 2 γ 0 ) 2 ∼ α 0 2 m 2 d σ χ χ d Ω = χ v 2 sin 2 ( θ / 2) + m 2 m 4 (4 m 2 γ 0 « As big as a barn » for in MeV range m γ 0

DIRECT DETECTION & SIDM PARAMETER SPACE α 0 = 10 � 2 α Hambye, M.T., Vandecasteele, Vanderheyden ‘18

DIRECT DETECTION TESTING SELF-INTERACTING FIMP DIRECT DETECTION & SIDM PARAMETER SPACE α 0 = 10 � 2 α Hambye, M.T., Vandecasteele, Vanderheyden ‘18

PART II SOLAR MASS BH FROM SIDM

m NS ∼ m � N B ∼ 10 57 v DM ∼ 200 km/s . Neutron Star (not to the scale) DM (not to the scale)

DM + NS → BH DM capture thermalization annihilation self-gravitation assumes DM does not annihilate (asymmetric DM) mini-black hole black hole

ASYMMETRIC DM Ω DM = m DM Y DM ≈ 5 = O (1) Ω B m N Y B 1 10 - 4 10 - 8 Baryons avoiding Baryon asymmetry Abundancies 10 - 12 WIMP freezing-out 10 - 16 10 - 20 10 50 100 500 1000 5000 1 ¥ 10 4 M dm T Crooked Forest (West Pomerania, Poland)

CAPTURE OF DM IN NS Capture rate Goldman & Nussinov (1989) - Kouvaris (2008) ✓ σ ◆ dN acc R ? R Sch √ ρ dm , 1 = 6 π Min dt m dm v dm 1 − R Sch /R ? σ cr Critical cross section σ cr = 0 . 45 m n R ? /M ? ≈ 1 . 3 × 10 − 45 cm 2 (neutron star) Maximal mass captured M acc ∼ 10 � 15 M � N acc ≈ 10 39 (TeV /m dm )

DM + NS → BH N acc ∼ 10 39 (TeV /m dm ) DM capture Goldman & Nussinov (1989) ⌘ 2 ✓ 10 − 45 cm 2 ◆ ⇣ m dm t th ∼ 10 2 yr Kouvaris & Tinyakov (2010) TeV σ thermalization ◆ 1 / 2 ✓ T c ✓ TeV ◆ 1 / 2 ◆ 1 / 2 ✓ T c r th ≈ ∼ 10 cm 10 5 K G ρ c m dm m dm ✓ TeV ◆ 5 / 2 N acc m dm & ρ c ∼ 10 39 GeV N cr & 10 38 self-gravitation → r 3 cm 3 m dm th ✓ TeV ◆ 3 ◆ 3 ✓ M Pl ∼ 5 · 10 48 mini-black hole N Ch & m m dm Bondi accretion dt = 4 π G 2 M 2 ρ c − π 3 dM → M bh & 10 � 20 M � 15 R 2 T 4 black hole c 2 s Kouvaris & Tinyakov (2013) Hawking radiation

SIDM + NS → BH WIMPS THAT WOULD DEVOUR STARS candidates that alleviate CDM issues 1 J2124-3358 0.100 fraction of collapsed NS ( f ) (270 pc;7.2 Gyr) fraction 0.010 of NS transformed 0.001 into BH 10 - 4 10 - 5 - 51 - 50 - 49 - 48 - 47 - 46 Log [ σ χ n / cm 2 ] Kouvaris, Tinyakov & MT (2018)

SOLAR MASS BINARY MERGERS

BACKUP

INTERMEDIATE REGIME : RECOMBINATION

CONSTRAINTS ON MILLICHARGED PARTICLES log κ log( m χ / eV)

CONSTRAINTS ON DARK PHOTON ✏ (old) compilation from Redondo & Ringwald, 2010

WIMPS THAT WOULD DEVOUR STARS ! ✓ t ✓ σ ◆ ◆ M acc ∼ 10 39 TeV ρ dm DM capture Min , 1 GeV/cm 3 Gyr σ cr Goldman & Nussinov (1989) Goldman & Nussinov (1989) ⌘ 2 ✓ 10 − 45 cm 2 ◆ ⇣ m dm t th ∼ 10 2 yr Kouvaris & Tinyakov (2010) Kouvaris & Tinyakov (2010) TeV σ thermalization ✓ TeV ◆ 1 / 2 ✓ T c ◆ 1 / 2 ◆ 1 / 2 ✓ T c r th ≈ ∼ 10 cm 10 5 K G ρ c m dm m dm ◆ 3 / 2 ✓ TeV N acc m dm & ρ c ∼ 10 39 GeV N cr & 10 38 self-gravitation → r 3 m dm cm 3 th higher density, higher T, further cooling, further collapse ✓ TeV ◆ 3 ◆ 3 & k F ∼ N 1 / 3 GNm 2 ✓ M Pl mini-black hole ∼ 5 · 10 48 dm N Ch & → m m dm R R Overcoming Fermi pressure requires m dm & 1000 TeV black hole Bramante, Linden & Tsai (2017);Kouvaris, Tinyakov & MT (2018)

PRIMORDIAL BLACK HOLES ? Figure from Garcia-Bellido & Clesse (2018)