NewDark
Earth-Scattering of Dark Matter: when Dark Matter particle physics - - PowerPoint PPT Presentation
Earth-Scattering of Dark Matter: when Dark Matter particle physics - - PowerPoint PPT Presentation
Earth-Scattering of Dark Matter: when Dark Matter particle physics and astrophysics collide Bradley J. Kavanagh LPTHE - Paris VI Based on arXiv:1611.05453 with Riccardo Catena and Chris Kouvaris MIAPP, Munich - 21st March 2017
Local DM density: ρχ ∼ 0.3 GeV/cm3
Dark Matter is heavier in Munich
Local DM density: ρχ ∼ 0.3 GeV/cm3
Dark Matter is heavier in Munich
In the UK, for mχ ∼ 150 GeV you get about 1 DM particle per glass…
Local DM density: ρχ ∼ 0.3 GeV/cm3
Dark Matter is heavier in Munich
In the UK, for mχ ∼ 150 GeV you get about 1 DM particle per glass… In Munich, you need mχ ∼ 300 GeV to get 1 DM particle per glass…
NewDark
@BradleyKavanagh bkavanagh@lpthe.jussieu.fr
Bradley J. Kavanagh LPTHE - Paris VI MIAPP, Munich - 21st March 2017
Earth-Scattering of Dark Matter:
when Dark Matter particle physics and astrophysics collide
Based on arXiv:1611.05453 with Riccardo Catena and Chris Kouvaris
Astrophysics Particle physics
Astrophysics Particle physics Nuclear Physics
Astrophysics Particle physics
‘Standard’ SI/SD WIMPs with SHM distribution
Astrophysics
Reconstructing DM parameters without astro assumptions
1303.6868, 1312.1852, 1410.8051, 1609.08630 and others
Astrophysics
Reconstructing DM parameters without astro assumptions
1303.6868, 1312.1852, 1410.8051, 1609.08630 and others
Particle physics
Discriminating DM
- perators
1505.07406
DM-SM operator running and mixing
1605.04917, 1702.00016
Astrophysics
Reconstructing DM parameters without astro assumptions
1303.6868, 1312.1852, 1410.8051, 1609.08630 and others
Particle physics
Discriminating DM
- perators
1505.07406
DM-SM operator running and mixing
1605.04917, 1702.00016
Earth-Scattering of DM?
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Direct Detection of DM (in space?)
χ
Detector Unscattered (free) DM: f0(v)
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Direct Detection of DM on Earth
χ
Detector Unscattered (free) DM: f0(v)
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Earth-Scattering - Attenuation
χ
Detector Previous calculations usually only consider DM attenuation
Kouvaris & Shoemaker [1405.1729,1509.08720] DAMA [1505.05336] Zaharijas & Farrar [astro-ph/0406531]
f(v) → f0(v) − fA(v)
Attenuation of DM flux:
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Earth-Scattering - Deflection
χ
Detector
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM Emken, Kouvaris & Shoemaker [1702.07750] (see later)
Earth-Scattering - Deflection
χ
Detector
Collar & Avignone [PLB 275, 1992 and others]
Considered in early Monte Carlo simulations… Can treat (without MC) in the ‘single scatter’ approximation…
λ RE
Assuming DM mean free path As well as more recent ones…
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
˜ f(v) = f0(v) − fA(v) + fD(v) Earth-Scattering
Detector Total DM velocity distribution:
χ
altered flux, daily modulation, directionality…
λ RE
Assuming DM mean free path Consider both attenuation and deflection in an analytic framework (‘Single scatter’) Consider non-standard DM-nucleon interactions (e.g. NREFT)
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
The current landscape
0.1 1 10 100 300
mχ [GeV]
10−46 10−45 10−44 10−43 10−42 10−41 10−40 10−39 10−38 10−37 10−36 10−35 10−34
ρ0.3 σp
SI [cm2]
LUX CRESST-II
How big is the probability of scattering in the Earth?
CRESST-II [1509.01515] LUX [1608.07648] + many others…
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
0.1 1 10 100 300
mχ [GeV]
10−46 10−45 10−44 10−43 10−42 10−41 10−40 10−39 10−38 10−37 10−36 10−35 10−34
ρ0.3 σp
SI [cm2]
LUX CRESST-II p = 5 % p = 10% p = 1%
The current landscape
What effect can DM scattering in the Earth have?
CRESST-II [1509.01515] LUX [1608.07648] + many others…
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
0.1 1 10 100 300
mχ [GeV]
10−46 10−45 10−44 10−43 10−42 10−41 10−40 10−39 10−38 10−37 10−36 10−35 10−34
ρ0.3 σp
SI [cm2]
LUX CRESST-II p = 5 % p = 10% p = 1%
The current landscape
What effect can DM scattering in the Earth have?
CRESST-II [1509.01515] LUX [1608.07648] + many others…
Focus on this region
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Earth-Scattering Calculation
Detector Total DM velocity distribution:
χ
λ RE
Assuming DM mean free path
˜ f(v) = f0(v) − fA(v) + fD(v)
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Astrophysics of DM (the simple picture)
Standard Halo Model (SHM) is typically assumed: isotropic, spherically symmetric distribution of particles with . Leads to a Maxwell-Boltzmann (MB) distribution (in the lab frame): ρ(r) ∝ r−2 fLab(v) = (2πσ2
v)−3/2 exp
- −(v − ve)2
2σ2
v
- Θ(|v − ve| − vesc)
[See Nassim Bozorgnia’s talk 06/03]
f(v) = v2
- f(v) dΩv
This is our ‘free’ distribution: f0(v)
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Attenuation
Detector
A B
v = (v, cos θ, φ) f0(v) − fA(v) = f0(v) exp
- −d(cos θ)
λ(v)
- λ(v)−1 = n σ(v)
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
deff = 1 ¯ n
- AB
n(r)dl ¯ λ(v)−1 = ¯ n σ(v) f0(v) − fA(v) = f0(v) exp
- −deff(cos θ)
¯ λ(v)
- Attenuation
Detector
A B
v = (v, cos θ, φ)
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
deff,i = 1 ¯ ni
- AB
ni(r)dl ¯ λi(v)−1 = ¯ ni σ(v)
Attenuation
Detector
A B
v = (v, cos θ, φ) f0(v) − fA(v) = f0(v) exp
- −
species
- i
deff,i(cos θ) ¯ λi(v)
- Sum over 8 most abundant elements in the Earth: O, Si, Mg, Fe, Ca, Na, S, Al
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Effective Earth-crossing distance
Most scattering comes from Oxygen (in the mantle) and Iron (in the core)
0.0 0.2 0.4 0.6 0.8 1.0 r/RE 0.0 0.5 1.0 1.5 2.0 n(r) [cm−3] ×1023
Oxygen Iron
NB: little Earth-scattering for spin-dependent interactions
π/4 π/2 θ 0.0 0.2 0.4 0.6 0.8 1.0 1.2 ¯ n deff(θ) [cm−2] ×1032
Oxygen Iron
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Deflection
v = (v, cos θ, φ)
Detector
A B C
v = (v, cos θ, φ) ¯ λi(v)−1 = ¯ ni σ(v)
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Deflection
v = (v, cos θ, φ)
Detector
A B C
v = (v, cos θ, φ) ¯ λi(v)−1 = ¯ ni σ(v) κi = v/v fD(v) =
species
- i
- d2ˆ
v deff,i(cos θ) λi(κiv) (κi)4 2π f0(κiv, ˆ v)Pi(cos α)
[Detailed calculation in the paper]
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Deflection
v = (v, cos θ, φ)
Detector
A B C
v = (v, cos θ, φ) ¯ λi(v)−1 = ¯ ni σ(v) κi = v/v fD(v) =
species
- i
- d2ˆ
v deff,i(cos θ) λi(κiv) (κi)4 2π f0(κiv, ˆ v)Pi(cos α)
Depends on total cross section Depends on differential cross section
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
NREFT operator basis SI SD
O1 = 1 O4 = ~ Sχ · ~ SN
[1008.1591, 1203.3542, 1308.6288, 1505.03117]
Write down all possible non-relativistic (NR) WIMP-nucleon operators which can mediate the elastic scattering.
[Fan et al - 1008.1591, Fitzpatrick et al. - 1203.3542]
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
NREFT operator basis
O1 = 1 O3 = i~ SN · (~ q × ~ v⊥)/mN O4 = ~ Sχ · ~ SN O5 = i~ Sχ · (~ q × ~ v⊥)/mN O6 = (~ Sχ · ~ q)(~ SN · ~ q)/m2
N
O7 = ~ SN · ~ v⊥ O8 = ~ Sχ · ~ v⊥ O9 = i~ Sχ · (~ SN × ~ q)/mN O10 = i~ SN · ~ q/mN O11 = i~ Sχ · ~ q/mN
SI SD
[1008.1591, 1203.3542, 1308.6288, 1505.03117]
O12 = ~ Sχ · (~ SN × ~ v⊥) O13 = i(~ Sχ · ~ v⊥)(~ SN · ~ q)/mN O14 = i(~ Sχ · ~ q)(~ SN · ~ v⊥)/mN O15 = −(~ Sχ · ~ q)((~ SN × ~ v⊥) · ~ q/m2
N
. . . NB: two sets of operators, one for protons and one for neutrons… Write down all possible non-relativistic (NR) WIMP-nucleon operators which can mediate the elastic scattering.
[Fan et al - 1008.1591, Fitzpatrick et al. - 1203.3542]
- v⊥ =
v +
- q
2µχN
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Energy spectra
Standard SI/SD int.
mχ = 100 GeV
dσ dER ∼ 1/v2
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Energy spectra mχ = 100 GeV
dσ dER ∼ v2
⊥/v2
dσ dER ∼ q2/v2
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
DM deflection distribution
P(cos α) = 1 σ dσ dER dER d cos α
- α
(α)
- χ =
- α
(α)
- χ =
Forward Backward
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
- α
(α)
- χ =
DM deflection distribution
P(cos α) = 1 σ dσ dER dER d cos α O12 = Sχ · ( SN × v⊥) ⇒ d dER ∼ ER v2 O1 = 1 ⇒ dσ dER ∼ 1 v2 O8 = Sχ · v⊥ ⇒ d dER ∼ (1 − mN ER 2µ2
χN v2 )
Standard SI
Forward Backward
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Constraints on NREFT operators
0.1 1 10 100 300
mχ [GeV]
10−40 10−39 10−38 10−37 10−36 10−35 10−34 10−33 10−32 10−31 10−30 10−29 10−28
ρ0.3 ˜ σp
8 [cm2]
LUX C R E S S T
- I
I p = 50% p = 1 % p = 1%
Operator ˆ O8 0.1 1 10 100 300
mχ [GeV]
10−42 10−40 10−38 10−36 10−34 10−32 10−30 10−28 10−26
ρ0.3 ˜ σp
12 [cm2]
LUX CRESST-II p = 5 % p = 1 % p = 1%
Operator ˆ O12
Focus on low mass DM: mχ = 0.5 GeV Fix couplings to give 10% probability of scattering Focus on SI operator (O1), as well as O8 and O12:
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Deflection
v = (v, cos θ, φ)
Detector
A B C
v = (v, cos θ, φ) ¯ λi(v)−1 = ¯ ni σ(v) κi = v/v fD(v) =
species
- i
- d2ˆ
v deff,i(cos θ) λi(κiv) (κi)4 2π f0(κiv, ˆ v)Pi(cos α)
Depends on total cross section Depends on differential cross section
Now we have everything we need!
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
EARTHSHADOW Code
EARTHSHADOW code is available online at: github.com/bradkav/EarthShadow Including routines, numerical results, plots and animations…
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Results
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 ˜ f(v, γ) [10−3 km/s]
Operator O1 − mχ = 0.5 GeV
Free γ = 0 γ = π/2 γ = π
100 200 300 400 500 600 700 800 v [km/s] 0.7 0.8 0.9 1.0 1.1 ˜ f(v, γ)/f0(v)
Speed Distribution - Operator 1
Detector
Calculate DM speed distribution after Earth scattering: ve ˜ f(v, γ)
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Speed Distribution - Operator 1
Detector
Calculate DM speed distribution after Earth scattering: ve
100 200 300 400 500 600 700 v [km/s]
π 4 π 2 3π 4
π γ = cos1(hˆ vχi · ˆ rdet)
- 1 %
- 10 %
- 5 %
- 1 %
1 %
Operator O1 mχ = 0.5 GeV
- 30%
- 20%
- 10%
0% 10% 20% 30%
Percentage change in speed dist. ˜ f(v, γ)
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Speed Distribution - O1 vs O8
Detector
100 200 300 400 500 600 700 v [km/s]
π 4 π 2 3π 4
π γ = cos1(hˆ vχi · ˆ rdet)
- 1 %
- 10 %
- 5 %
- 1
% 1 %
Operator O1 mχ = 0.5 GeV
- 30%
- 20%
- 10%
0% 10% 20% 30%
100 200 300 400 500 600 700 v [km/s]
π 4 π 2 3π 4
π γ = cos1(hˆ vχi · ˆ rdet)
- 1 %
- 2
5 %
- 10 %
- 5 %
- 1 %
1 % 5 %
Operator O8 mχ = 0.5 GeV
- 30%
- 20%
- 10%
0% 10% 20% 30%
Operator 8 - preferentially forward deflection
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Speed Distribution - O1 vs O12
Detector
100 200 300 400 500 600 700 v [km/s]
π 4 π 2 3π 4
π γ = cos1(hˆ vχi · ˆ rdet)
- 1 %
- 10 %
- 5 %
- 1
% 1 %
Operator O1 mχ = 0.5 GeV
- 30%
- 20%
- 10%
0% 10% 20% 30%
Operator 12 - preferentially backward deflection
100 200 300 400 500 600 700 v [km/s]
π 4 π 2 3π 4
π γ = cos1(hˆ vχi · ˆ rdet)
- 50 %
- 25 %
- 10 %
- 5
%
- 1 %
1 % 5 % 1 %
Operator O12 mχ = 0.5 GeV
- 30%
- 20%
- 10%
0% 10% 20% 30%
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Low mass vs High mass
Detector
100 200 300 400 500 600 700 v [km/s]
π 4 π 2 3π 4
π γ = cos1(hˆ vχi · ˆ rdet)
- 1 %
- 10 %
- 5 %
- 1
% 1 %
Operator O1 mχ = 0.5 GeV
- 30%
- 20%
- 10%
0% 10% 20% 30%
Higher mass DM
100 200 300 400 500 600 700 v [km/s]
π 4 π 2 3π 4
π γ = cos1(hˆ vχi · ˆ rdet)
- 1 %
- 10 %
- 5
%
- 1
% 1 % 5 % 10 % 2 5 % 50 %
Operator O1 mχ = 50 GeV
- 30%
- 20%
- 10%
0% 10% 20% 30%
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Γout =
- v·r>0
d2r
- d3v ˜
f(v, r) (v · r)
Sanity check
Compare rate of DM particles entering the Earth… Γin = πR⊕v …and rate of DM particle leaving the Earth…
Detector
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 ˜ f(v, γ) [10−3 km/s]
Operator O1 − mχ = 0.5 GeV
Free γ = 0 γ = π/2 γ = π
100 200 300 400 500 600 700 800 v [km/s] 0.7 0.8 0.9 1.0 1.1 ˜ f(v, γ)/f0(v)
Event Rate
Calculate number of signal events in a CRESST-II like experiment, with and without the effects of Earth-Scattering, and . Npert Nfree Scattering predominantly with Oxygen and Calcium. DM particles within of the energy threshold 3 σE Eth ∼ 300 eV
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Mapping the CRESST-II Rate
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Operator 1 - isotropic deflection
LNGS - Operator 1
LNGS - Gran Sasso Lab, Italy
6 12 18 24 time [hours] 0.9 1.0 1.1 1.2 Npert/Nfree LNGS (42.5 N)
- Atten. only
Atten.+Defl. O1
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Operator 8 - forward deflection
LNGS - Operator 8
LNGS - Gran Sasso Lab, Italy
6 12 18 24 time [hours] 0.9 1.0 1.1 1.2 Npert/Nfree LNGS (42.5 N)
- Atten. only
Atten.+Defl. O1 O8
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
LNGS - Operator 12
LNGS - Gran Sasso Lab, Italy
6 12 18 24 time [hours] 0.9 1.0 1.1 1.2 Npert/Nfree LNGS (42.5 N)
- Atten. only
Atten.+Defl. O1 O8 O12
Operator 12 - backward deflection
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Operator 1 - isotropic deflection
6 12 18 24 time [hours] 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 Npert/Nfree SUPL (37.1 S)
O1 O8 O12
SUPL - Operator 1
SUPL - Stawell Underground Physics Lab, Australia
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Around the world
6 12 18 24 time [hours] 0.9 1.0 1.1 1.2 Npert/Nfree LNGS (42.5 N)
- Atten. only
Atten.+Defl. O1 O8 O12
6 12 18 24 time [hours] 0.9 1.0 1.1 1.2 Npert/Nfree CJPL (28.2 N)
O1 O8 O12
6 12 18 24 time [hours] 0.8 0.9 1.0 1.1 1.2 Npert/Nfree INO (9.7 N)
O1 O8 O12
6 12 18 24 time [hours] 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 Npert/Nfree SUPL (37.1 S)
O1 O8 O12
India-based Neutrino Observatory China Jinping Lab
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Implications of Earth-Scattering
Smoking gun signature: daily modulation + location dependence could confirm DM nature Possibility to distinguish different interactions with different amplitude and phase of modulation Careful calculation (including deflection and attenuation) in the ‘single-scatter’ regime
6 12 18 24 time [hours] 0.9 1.0 1.1 1.2 Npert/Nfree LNGS (42.5 N)
- Atten. only
Atten.+Defl. O1 O8 O12
BJK, Catena & Kouvaris [1611.05453]
EARTHSHADOW code available online to include these effects: github.com/bradkav/EarthShadow
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Ideas for the future
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Mapping out the parameter space
Continue mapping out parameter space and explore impact on upper limits for a range of interactions… (mχ, σp)
0.1 1 10 100 300
mχ [GeV]
10−46 10−45 10−44 10−43 10−42 10−41 10−40 10−39 10−38 10−37 10−36 10−35 10−34
ρ0.3 σp
SI [cm2]
LUX CRESST-II p = 5 % p = 1 % p = 1%
0.1 1 10 100 300
mχ [GeV]
10−42 10−40 10−38 10−36 10−34 10−32 10−30 10−28 10−26
ρ0.3 ˜ σp
12 [cm2]
LUX CRESST-II p = 5 % p = 1 % p = 1%
Operator ˆ O12
…and encourage experimental collaborations to explore full NREFT parameter space.
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Directionality
Distortion of should also lead to a directional signature
f(v)
Studied previously for very efficiency stopping
[1509.08720]
In our case, Earth-Scattering should give an excess of particles
- riginating from the ‘downward’
direction (depending on time of day) Detector
χ
Recent proposal for directional sensitivity to low mass DM using semiconductor detectors
[1703.05371]
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Astrophysical Uncertainties
How robust are these results against changes to the (free) velocity distribution?
6 12 18 24 time [hours] 0.8 0.9 1.0 1.1 1.2 Npert/Nfree INO (9.7 N)
O1 O8 O12
Doesn’t depend on spectral information, only timing information. Also, what about degeneracy between cross section and DM density…?
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Low mass Dark Matter
The ‘many-scatter’ regime for low mass DM? Low mass DM loses almost no energy on scattering
- α
(α)
- χ =
Forward Backward
For standard SI interactions the scattering is isotropic Should be able to model as a random walk/diffusion process
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
High mass Dark Matter
What about very heavy DM?
[1608.07648]
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
High mass Dark Matter
What about very heavy DM?
[1608.07648]
WIMPzillas!
[hep-ph/9810361, 1606.00923]
mχ ∼ 107 GeV pscat ∼ 1
for
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
High mass Dark Matter
What about very heavy DM? In the limit, DM is not deflected and loses no energy when scattering with Earth nuclei
mχ → ∞
But for finite , get a small deflection and energy loss.
mχ
Heavy DM effectively follows smooth, curved trajectories through the Earth
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Monte Carlo Simulations
State-of-the-art MC simulations are currently in development -
see Emken, Kouvaris & Shoemaker [1702.07750]
Takes deflection into account in a thin portion of Earth’s crust: But still need analytic calculations to test and calibrate!
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Future ideas
- Mapping out the parameter space - What are the signatures of
different DM-nucleon (DM-e? Long-range?) interactions?
- Directional signatures of Earth-Scattering - Does directional
sensitivity enhance these effects?
- The impact of astrophysical uncertainties - Would diurnal
modulation be a ‘clean’ signature? What about ?
- Low mass DM - Can we make progress in the diffusion regime?
- High mass DM - WIMPzilla trajectories should be simpler. What are
the signatures for heavy SIMP DM?
- Monte Carlo simulations - Can we tackle Earth-Scattering for an
arbitrary point in parameter space? How can we test/calibrate these simulations?
ρχ
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Backup Slides
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
INO - Operator 8
Operator O8
6 12 18 24 time [hours] 0.8 0.9 1.0 1.1 1.2 Npert/Nfree INO (9.7 N)
O1 O8 O12
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Mapping the CRESST-II Rate
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Mapping the CRESST-II Rate
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Mapping the CRESST-II Rate
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
fD(v) = dl λi(r, v) v v f0(v)P(v → v) d3v
Deflection α v v
C dl Rate of particles entering the region: dS nχ f0(v) v cos α dS d3v Probability of scattering in the region: dl λi(r, v) cos α P(v → v) d3v Rate of particles leaving the region: nχfD(v) v dS d3v Deflected velocity distribution:
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Probability of scattering from one velocity to another can be written:
Deflection
Deflected velocity distribution (from a single point): fixed by kinematics (for a given ) α Need to integrate over all incoming velocities and over all points C: P(v → v) = 1 2π 1 v2 δ(v − v/κi) P(cos α) = 1 2π v v3 δ(v − κiv) P(cos α) fD(v) = 1 2π
- AB
dl λi(r, v)
- d3v v2
v4 δ(v − κiv)f0(v, ˆ v)Pi(cos α) Collect everything together, and sum over Earth species… fD(v) = dl λi(r, v) v v f0(v)P(v → v) d3v v/v ≡ κi
Bradley J Kavanagh (LPTHE, Paris) MIAPP, Munich - 21st Mar. 2017 Earth-scattering of DM
Deflection
fixed by kinematics (for a given ) α Then integrate over all incoming velocities and over all points C: Collect everything together, and sum over Earth species… v/v ≡ κi
α v v
C dl dS Equate rate of particles entering and leaving region, having scattered… fD(v) = 1 2π
- AB
dl λi(r, v)
- d3v v2