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ITP seminarRecent results from Dark Matter direct detection
experiments and their interpretation
Thomas Schwetz
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 1
Outline
• introduction to Dark Matter direct detection
• recent hints for low-mass WIMPsCDMS, CoGeNT, CRESST, DAMA
and their (in)compatibility with boundsCDMS, XENON
• focus on spin-independent elastic scattering
• brief comments on spin-dependent scattering andmore exotic scenarios
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 2
Dark Matter in a Milkyway-like Galaxy
Via Lactea N-body DM simulation Diemand, Kuhlen, Madau, astro-ph/0611370
you are here
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 3
Dark Matter distribution
“standard halo model”:
local DM densityρχ ≈ 0.389 ± 0.025 GeV cm−3
Catena, Ullio, 0907.0018
⇒ nχ ≈ 4000 m−3
(
100 GeV
mχ
)
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 4
Dark Matter distribution
“standard halo model”:
local DM densityρχ ≈ 0.389 ± 0.025 GeV cm−3
Catena, Ullio, 0907.0018
⇒ nχ ≈ 4000 m−3
(
100 GeV
mχ
)
Maxwellian velocity distribution (in halo rest frame)
fgal(~v) ≈
N exp(
−v2/v2)
v < vesc
0 v > vesc
with v ≃ 220 km/s and vesc ≃ 600 km/sT. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 4
DM direct detection
. . . assuming DM has non-gravitational interactions (“WIMP”):
DM direct detection M. Goodman, E. Witten, PRD 1985
Look for recoil of DM-nucleus scattering:
χ+N → χ+N
cnts / keV recoil energy ER:
dN
dER
(t) ∝ ρχ
mχ
∫
v>vmin
d3vdσ
dER
v f⊕(~v, t)
vmin: minimal DM velocity required to produce recoil energy ER
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 5
DM nucleon scattering cross section
in general the interaction between χ and a nucleus can bespin-independent (SI) and/or spin-dependent (SD):
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 6
DM nucleon scattering cross section
in general the interaction between χ and a nucleus can bespin-independent (SI) and/or spin-dependent (SD):
Example: fermionic DM Leff = 1Λ2 (χqΓdarkχq) (ψΓvisψ)
S P V A T AT
Γdark,vis γ0 γ0γ5 γµ γµγ5 σµν σµνγ5
⇒ in the non-relativistic limit:• (S ⊗ S), (V ⊗ V ): spin-independent interaction• (A⊗A), (T ⊗ T ): spin-dependent interaction• other combinations are suppressed by O(v2) ∼ 10−6
e.g., A. Kurylov, M. Kamionkowski, hep-ph/0307185T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 6
DM nucleon scattering cross section
σSI = σp
µ2χN
µ2χp
[Zfp + (A− Z)fn]2
f 2p
|F (q)|2 ∝ A2 for fn ≈ fp
σSD =32µ2
χNG2F
2J + 1
[
a2pSpp(q) + apanSpn(q) + a2
nSnn(q)]
µχN (µχp): DM-nucleus(proton) reduced mass
fp, fn, ap, an: couplings to proton and neutron
F (q), Spp(q), Spn(q), Snn(q): nuclear structure functions
SI: A2 enhancement → (heavy nuclei)
SD: coupling mainly to unpaired n or p
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 7
DM velocity distribution
f⊕(~v, t) = fgal(~v + ~v⊙ + ~v⊕(t)) fgal(~v) ∝ exp(v2/v)
sun velocity: ~v⊙ = (0, 220, 0) + (10, 13, 7) km/searth velocity: ~v⊕(t) with v⊕ ≈ 30 km/s
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 8
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 9
Direct detection: where do we stand?
• many exps. running and setting relevant limits:
CDMS (Ge, Si), CoGeNT (Ge), COUPP (CF3I), CRESST(CaWO4), DAMA (NaI), Edelweiss (Ge), KIMS (CsI),PICASSO (F), SIMPLE (C2ClF5), TEXONO (Ge), XENON(Xe), ZEPLIN (Xe),. . .
• a few of them report “hints” for WIMP interactions:
CDMS?, CoGeNT?, CRESST?, DAMA?
which might point to WIMPs (SI) in the low-mass(∼10 GeV) region, or something more exotic. . .
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 10
Hints for low-mass WIMPs andelastic spin-independent scattering
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 11
Event spectrum
dN
dER
(t) =ρχ
mχ
σp|F (q)|2A2
2µ2p
∫
v>vmin(ER)
d3vf⊕(~v, t)
v
vmin : minimal DM velocity required to produce recoil energy ER
vmin =mχ +M
mχ
√
ER
2M⇒ mχ ≪M : vmin ≈
√
MER/2
mχ
need light target and/or low threshold on ER to see light WIMPs
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 12
Event spectrum
0 10 20 30 40 50E
nr [keV]
even
ts o
n G
e / k
eV [
arb.
Uni
ts] 5
1020304050
mχ [GeV]
spectrum gets shifted to low energies for low WIMPmasses ⇒energy threshold is crucial
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 13
SI elastic scattering exclusion curve
10 100mχ [GeV]
10-44
10-43
10-42
10-41
10-40
σ p [cm
2 ]
10 100
energy threshold
mχ ~ mN
exposure
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 14
low-mass WIMP hints
CDMS-IICoGeNT
CRESST-IIDAMA
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 15
CDMS-II
Germanium detector, recoil energy range 10–100 keV
• 0912.3592 July 2007-Sep 2008, 612 kg day: 2 candidate ev.
electron and nucl. recoilregions for two differentdetectors
candidates:12.3 keV and 15.5 keV
background: 0.8 ± 0.1 ± 0.2
probablitly for >= 2 ev: 23%
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 16
CDMS-II
10 100 1000mχ [GeV]
10-44
10-43
10-42
10-41
10-40
10-39
σ p [cm
2 ]
10 100 1000
CDMS 08+09 max-gap limitCDMS 09 max-likelihood fit
vesc
= 550 km/s
90% CL68% CL
90% CL
assuming a shape forthe distribution of the 0.8background events basedon the event distr. shownin fig. 3 of 0802.3530and performing a maxi-mum likelihood fit to thetwo observed events(no uncert. on bckg num-ber and shape included)
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 17
low-mass WIMP hints
CDMS-IICoGeNT
CRESST-IIDAMA
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 18
CoGeNT
Germanium detector with extremely low threshold of 0.4 keVee
exponential rise of eventsat low energiesclaim that it cannot beelectronic noise
Aalseth et al., 1002.4703
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 19
CoGeNT
3 10 100mχ [GeV]
10-44
10-43
10-42
10-41
10-40
10-39
σ p [cm
2 ]
10 100
CDMS 08+09 limit 90% CLCDMS 09 fit, 68% CLCoGeNT 90, 99.73% CL, no bgCoGeNT 90% CL, exp bkg
vesc
= 550 km/s
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 20
low-mass WIMP hints
CDMS-IICoGeNT
CRESST-IIDAMA
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 21
DAMA/LIBRA annual modulation signal
Scinitillation light in NaI detector, 1.17 t yr exposure (13 yrs)∼ 1 cnts/d/kg/keV → ∼ 4 × 105 events/keV in DAMA/LIBRA∼ 8.9σ evidence for an annual modulation of the count rate withmaximum at day 146 ± 7 (June 2nd: 152) Bernabei et al., 1002.1028
2-6 keV
Time (day)
Res
idua
ls (
cpd/
kg/k
eV) DAMA/NaI (0.29 ton×yr)
(target mass = 87.3 kg)DAMA/LIBRA (0.53 ton×yr)
(target mass = 232.8 kg)
Bernabei et al., 0804.2741
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 22
DAMA/LIBRA annual modulation signal
Scinitillation light in NaI detector, 1.17 t yr exposure (13 yrs)∼ 1 cnts/d/kg/keV → ∼ 4 × 105 events/keV in DAMA/LIBRA∼ 8.9σ evidence for an annual modulation of the count rate withmaximum at day 146 ± 7 (June 2nd: 152) Bernabei et al., 1002.1028
Bernabei et al., 1002.1028
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 22
DAMA/LIBRA annual modulation signal
Scinitillation light in NaI detector, 1.17 t yr exposure (13 yrs)∼ 1 cnts/d/kg/keV → ∼ 4 × 105 events/keV in DAMA/LIBRA∼ 8.9σ evidence for an annual modulation of the count rate withmaximum at day 146 ± 7 (June 2nd: 152) Bernabei et al., 1002.1028
Energy (keV)
S m (
cpd/
kg/k
eV)
-0.05
-0.025
0
0.025
0.05
0 2 4 6 8 10 12 14 16 18 20
energy shape of modulation is important for constraining paramsChang, Pierce, Weiner, 0808.0196; Fairbairn, TS, 0808.0704
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 22
Quenching
DAMA measures energy in“electron equivalent” (keVee)
only a fraction q of nuclear recoil energy ER isobservable as scintillation signal in DAMA:
Eobs = q × ER
with qNa ≈ 0.3, qI ≈ 0.09
⇒ the energy threshold of 2 keVee implies athreshold in ER of 6.7 keV for Na and 22 keV for I.
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 23
Channeling
Drobyshevski, 0706.3095; Bernabei et al., 0710.0288
with a certain probability a recoiling nucleus will not interact withthe crystal but loose its energy only electro-magnetically: q ≈ 1
no measurments available at relevant energies
Bozorgnia, Gelmini, Gondolo, 1006.3110 channeling negligible in NaIT. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 24
Fitting DAMA
3 10 100mχ [GeV]
10-44
10-43
10-42
10-41
10-40
10-39
σ p [cm
2 ]
10 100
CDMS 08+09 limit 90% CLCDMS 09 fit, 68% CLDAMA 90, 99.73% CL no chanDAMA 90, 99.73% CL with chan CoGeNT 90, 99.73% CL, no bgCoGeNT 90% CL, exp bkg
vesc
= 550 km/s
region with channeling assumes fraction of chan. according to Bernabei et al., 0710.0288
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 25
DAMA vs CoGeNT
can we make CoGeNT and DAMA consistent?Hooper, Collar, Hall, McKinsey, 1007.1005
How well do we know the quenching factor of Na?
3 10mχ [GeV]
10-41
10-40
10-39
σ p [cm
2 ]
10
vesc
= 550 km/s
qNa
= 0.3qNa
= 0.6
90% CL, 3σ
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 26
DAMA vs CoGeNT
can we make CoGeNT and DAMA consistent?Hooper, Collar, Hall, McKinsey, 1007.1005
How well do we know the quenching factor of Na?
3 10mχ [GeV]
10-41
10-40
10-39
σ p [cm
2 ]
10
vesc
= 550 km/s
solid: qNa
= 0.3 +/- 0.03dashed: q
Na = 0.3 +/- 0.1
DAMA
CoGeNT
90%, 99.73% CL (2 dof)
χ2DAMA = 8.2/(12 − 2) (61%)χ2
CoG = 46/(56 − 4) (71%)
χ2glb,0.1 = 75/(68 − 4) (1.6%)χ2
glb,0.03 = 95/(68 − 4) (0.7%)
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 26
DAMA vs CoGeNT
can we make CoGeNT and DAMA consistent?Hooper, Collar, Hall, McKinsey, 1007.1005
How well do we know the quenching factor of Na?
3 10mχ [GeV]
10-41
10-40
10-39
σ p [cm
2 ]
10
vesc
= 550 km/s
solid: qNa
= 0.3 +/- 0.03dashed: q
Na = 0.3 +/- 0.1
DAMA
CoGeNT
90%, 99.73% CL (2 dof)0 50 100 150 200 250
Enr
[keV]
0
0.1
0.2
0.3
0.4
0.5
quen
chin
g fa
ctor
Tovey et al., PLB 1998Chagani et al., JINST, 0806.1916
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 27
DAMA vs CoGeNT
can we make CoGeNT and DAMA consistent?Hooper, Collar, Hall, McKinsey, 1007.1005
How well do we know the quenching factor of Na?
3 10mχ [GeV]
10-41
10-40
10-39
σ p [cm
2 ]
10
vesc
= 550 km/s
solid: qNa
= 0.3 +/- 0.03dashed: q
Na = 0.3 +/- 0.1
DAMA
CoGeNT
90%, 99.73% CL (2 dof)0 50 100 150 200 250
Enr
[keV]
0
0.1
0.2
0.3
0.4
0.5
quen
chin
g fa
ctor
Tovey et al., PLB 1998Chagani et al., JINST, 0806.1916
semi-empirical fitTretyak 0911.3041
Iodine
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 27
low-mass WIMP hints
CDMS-IICoGeNT
CRESST-IIDAMA
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 28
CRESST-II
Talk by W. Seidel @ WONDER 2010, March 22 to 23
CaWO4 target, 9 detectors, about 400 kg d
excess of single-scatter events in O-band (magenta)
10 15 20 25 30 35 40E
nr [keV]
0
1
2
3
4
even
ts p
er k
eV
m = 12 GeV
shape agrees with ∼ 10 GeV WIMPT. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 29
CRESST-II
Talk by W. Seidel @ IDM10: CaWO4 target, about 400 kg d
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 30
Attempt CRESST O band fit
3 10 100mχ [GeV]
10-44
10-43
10-42
10-41
10-40
10-39
σ p [cm
2 ]
10 100
CDMS 08+09 limit 90% CLCDMS 09 fit, 68% CLDAMA 90, 99.73% CL no chanDAMA 90, 99.73% CL with chan CoGeNT 90, 99.73% CL, no bgCoGeNT 90% CL, exp bkgCRESST O+W bandsCRESST O-band
vesc
= 550 km/s
WARNING:Do not take too serious - very speculative! ⇒ regions willshift/shrink/go away (?) when detailed information on CRESSTevents and background becomes available (publ. Sept. 2010?)T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 31
Constraints from CDMS and XENON
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 32
CDMS Si constraints
3 10 100mχ [GeV]
10-44
10-43
10-42
10-41
10-40
10-39
σ p [cm
2 ]
10 100
CDMS Si 2005
vesc
= 550 km/s
CDMS data on Si (astro-ph/0509259): 12 kg day, 7 keV thresholdmore data on tape ⇒ new paper expected very soon
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 33
XENON-10
2 phase (gas/liquid) Xenon detector @ Gran SassoOct 2006 - Feb 2007, 316 kg day exposure
0706.0039: original blind analysis: 10 events0910.3698: revised cuts: 13 events, extended energy window
0 10 20 30 40 50 60 70 80nuclear recoil energy [keV]
2007 analysis (10 events / exp. backgr.: ~7.0)
2009 analysis (13 events / exp. backgr.: ~7.4)
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 34
XENON-100
11.7 days, 40 kg fid., ∼ 230 kg day effective exp.
XENON100, 1005.0380
S1: prompt signal from scintillationS2: delayed signal from ionization
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 35
Leff
translate S1 signal [PE] into Enr [keV]: Enr = S1Leff (Enr)
1Ly
Se
Sn
1 10 100E
nr [keV]
0
0.1
0.2
0.3
0.4
Lef
f
AkimovEtAlAprileEtAl05AprileEtAl08ArneodoEtAlChepelEtAlManzurEtAlSorensenEtAl
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 36
Leff
translate S1 signal [PE] into Enr [keV]: Enr = S1Leff (Enr)
1Ly
Se
Sn
1 10 100E
nr [keV]
0
0.1
0.2
0.3
0.4
Lef
f
AkimovEtAlAprileEtAl05AprileEtAl08ArneodoEtAlChepelEtAlManzurEtAlSorensenEtAl
all except Sorensen Et Al
Manzur Et Al + Arneodo Et Al
Sorensen Et Al + Aprile Et Al 08
3 exemplary fits, extrapolating with straight lines at low energiesT. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 36
Acceptance window in XENON100
acceptance window is defined by cuts on S1 and S2 # of PEs:
4 < S1 < 20 , 300 < S2 < 〈S2〉S1
• this translates into window in Enr according to Leff
• Poisson statistics of PEs implies smearing of the thresholds
0 10 20 30 40E
nr [keV]
0
0.1
0.2
0.3
0.4
0.5
acce
ptan
ce d
ue to
Poi
sson
dis
trib
utio
n of
PE
s
10 GeV WIMP [arb. units]
1 10 100E
nr [keV]
0
0.1
0.2
0.3
0.4
Lef
f
AkimovEtAlAprileEtAl05AprileEtAl08ArneodoEtAlChepelEtAlManzurEtAlSorensenEtAl
all except Sorensen Et Al
Manzur Et Al + Arneodo Et Al
Sorensen Et Al + Aprile Et Al 08
same color codingT. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 37
Leff and the XENON bounds
3 10 100mχ [GeV]
10-44
10-43
10-42
10-41
10-40
10-39
σ p [cm
2 ]
10 100
solid: XENON100dashed: XENON10 1 10 100
Enr
[keV]
0
0.1
0.2
0.3
0.4
Lef
f
AkimovEtAlAprileEtAl05AprileEtAl08ArneodoEtAlChepelEtAlManzurEtAlSorensenEtAl
all except Sorensen Et Al
Manzur Et Al + Arneodo Et Al
Sorensen Et Al + Aprile Et Al 08
same color coding
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 38
Leff and the XENON bounds
3 10 100mχ [GeV]
10-44
10-43
10-42
10-41
10-40
10-39
σ p [cm
2 ]
10 100
solid: XENON100dashed: XENON10
1 10 100E
nr [keV]
0
0.1
0.2
0.3
0.4
Lef
f
AkimovEtAlAprileEtAl05AprileEtAl08ArneodoEtAlChepelEtAlManzurEtAlSorensenEtAl
all except Sorensen Et Al
Manzur Et Al + Arneodo Et Al
Sorensen Et Al + Aprile Et Al 08
heated discussion: Collar, McKinsey, 1005.0838; XENON100, 1005.2615;Collar, McKinsey, 1005.2615; Savage et al., 1006.0972; Collar, 1006.2031
Bezrukov, Kahlhöfer, Lindner
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 38
XENON S2 analysis
3 10 100mχ [GeV]
10-44
10-43
10-42
10-41
10-40
10-39
σ p [cm
2 ]
10 100
solid: XENON100dashed: XENON10
XENON10 S2 analysis
P. Sorensen, talk @ IDM10XENON10 analysisusing only S2 signal(ionization)Talk by P. Sorensen,
IDM conference, Montpellier 2010
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 39
XENON-100 exposure
Talk by E. Aprile, GGI conference, 19 May 2010
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 40
Summary elastic SI scattering
3 10mχ [GeV]
10-41
10-40
10-39
σ pSI [
cm2 ]
10
DAMA + CoGeNTCoGeNTDAMACRESSTCDMS Si (2005)CDMS GeXENON100 (mean L
eff)
XENON10 S2 analysisP. Sorensen, talk @ IDM2010
solid: qNa
= 0.3 +/- 0.03dashed: q
Na = 0.3 +/- 0.1
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 41
How to obtain ∼ 10 GeV WIMPs?
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 42
Scalar singlet DM
the most simple WIMP model:add a scalar singlet to the SM with a Z2 symmetry S → −SSilveira, Zee, 85; McDonald 94; Burgess, Pospelov, Veldhuis, 00; . . .
L = LSM +1
2∂νS∂
νS − 1
2µ2S2 − 1
2λ1S
4 − λ2S2φ†φ
communication with the SM via the “Higgs portal” λ2
for a given DM mass m2S = µ2 + λ2v
2 the requirement of acorrect thermal abundance fixes λ2 and all phenomenology(including Higgs searches at LHC)
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 43
Scalar singlet DM
the most simple WIMP model:add a scalar singlet to the SM with a Z2 symmetry S → −SSilveira, Zee, 85; McDonald 94; Burgess, Pospelov, Veldhuis, 00; . . .
He, Li, Li, Tandean, Tsai, 0912.4722 Andreas, Arina, Hambye,Ling, Tytgat, 1003.2595
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 43
light SUSY DM
MSSM neutralino: LEP Z0 invis width OK by making it mostlybino, but have to depart from CMSSM to make it light ⇒non-universal gaugino massese.g., Bottino, Donato, Fornengo, Scopel, 02,03,07,08,09; Hooper, Plehn, 02; Belanger,Boudjema, Cottrant, Pukhov, Rosier-Lees, 03; Asano, Matsumoto, Senami, Sugiyama, 09;Hisano, Nakayama, Yamanaka, 09 Kuflik, Pierce, Zurek, 1003.0682
Bs → µ+µ− and Tevatron light Higgs searches: mχ > 28 GeVFeldman, Liu, Nath, 1003.0437; Albornoz, Belanger, Boehm, Pukhov, Silk, 1009.4380
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 44
light SUSY DM
MSSM neutralino: LEP Z0 invis width OK by making it mostlybino, but have to depart from CMSSM to make it light ⇒non-universal gaugino massese.g., Bottino, Donato, Fornengo, Scopel, 02,03,07,08,09; Hooper, Plehn, 02; Belanger,Boudjema, Cottrant, Pukhov, Rosier-Lees, 03; Asano, Matsumoto, Senami, Sugiyama, 09;Hisano, Nakayama, Yamanaka, 09 Kuflik, Pierce, Zurek, 1003.0682
Bs → µ+µ− and Tevatron light Higgs searches: mχ > 28 GeVFeldman, Liu, Nath, 1003.0437; Albornoz, Belanger, Boehm, Pukhov, Silk, 1009.4380
NMSSM (singlino component): e.g., Gunion, Hooper, McElrath, hep-ph/0509024;Bae, Kim, Shin, 1005.5131; Das, Ellwanger, 1007.1151; Belikov, Gunion, Hooper, Tait,1009.0549; Gunion, Belikov, Hooper, 1009.2555; Draper, Liu, Wagner, Wang, Zhang, 1009.3963;Albornoz, Belanger, Boehm, Pukhov, Silk, 1009.4380; Kappl, Ratz, Winkler, 1010.0553
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 44
light SUSY DM
MSSM neutralino: LEP Z0 invis width OK by making it mostlybino, but have to depart from CMSSM to make it light ⇒non-universal gaugino massese.g., Bottino, Donato, Fornengo, Scopel, 02,03,07,08,09; Hooper, Plehn, 02; Belanger,Boudjema, Cottrant, Pukhov, Rosier-Lees, 03; Asano, Matsumoto, Senami, Sugiyama, 09;Hisano, Nakayama, Yamanaka, 09 Kuflik, Pierce, Zurek, 1003.0682
Bs → µ+µ− and Tevatron light Higgs searches: mχ > 28 GeVFeldman, Liu, Nath, 1003.0437; Albornoz, Belanger, Boehm, Pukhov, Silk, 1009.4380
NMSSM (singlino component): e.g., Gunion, Hooper, McElrath, hep-ph/0509024;Bae, Kim, Shin, 1005.5131; Das, Ellwanger, 1007.1151; Belikov, Gunion, Hooper, Tait,1009.0549; Gunion, Belikov, Hooper, 1009.2555; Draper, Liu, Wagner, Wang, Zhang, 1009.3963;Albornoz, Belanger, Boehm, Pukhov, Silk, 1009.4380; Kappl, Ratz, Winkler, 1010.0553
sneutrino: MSSM + νR Arkani-Hamed, Hall, Murayama, Tucker-Smith, Weiner, 00;Belanger, Kakizaki, Park, Kraml, Pukhov, 1008.0580
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 44
Asymmetric Dark Matter
Nussinov, 1985; Barr, Chivukula, Farhi, 1990; Barr, 1991; Kaplan, 1992; Kaplan, Luty, Zurek,
0901.4117; Shelton, Zurek, 1008.1997; Davoudiasl, Morrissey, Sigurdson, Tulin, 1008.2399;
Haba, Matsumoto, 1008.2487; McDonald, 1009.3227; Chun, 1009.0983; Buckley, Randall,
1009.0270; Gu, Lindner, Sarkar, Zhang, 1009.2690; Blennow, Dasgupta, Fernandez-Martinez,
Rius, 1009.3159
DM carries some quantum number
ΩDM ∼ ΩB ⇒ mDM ∼ mp
often predict DM in the several GeV range,direct detection scattering is model dependent
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 45
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 46
How to reconcile?
3 10mχ [GeV]
10-41
10-40
10-39
σ pSI [
cm2 ]
10
DAMA + CoGeNTCoGeNTDAMACRESSTCDMS Si (2005)CDMS GeXENON100 (mean L
eff)
XENON10 S2 analysisP. Sorensen, talk @ IDM2010
solid: qNa
= 0.3 +/- 0.03dashed: q
Na = 0.3 +/- 0.1
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 47
How to reconcile?
• experimental issues?∼ 10 GeV region is experimentally challengingsystematic uncertainties on quenching factors, energy scale,threshold effects, backgrounds. . . have to be understoodand taken into account before making strong statements
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 48
How to reconcile?
• experimental issues?∼ 10 GeV region is experimentally challengingsystematic uncertainties on quenching factors, energy scale,threshold effects, backgrounds. . . have to be understoodand taken into account before making strong statements
• modify astrophysics?changing v, vesc has little impact on consistencynon-standard halos (asymmetric, streams, dark disc) requireextreem params Fairbairn, Schwetz, 0808.0704, and others
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 48
How to reconcile?
• more exotic particle physics?spin-dependent interactioninelastic DM Tucker-Smith, Weiner, hep-ph/0101138
mirror DM R. Foot
leptophilic DM Fox, Poppitz, 0811.0399; Kopp, Niro, Schwetz, Zupan, 0907.3159
Form Factor DM Feldstein, Fitzpatrick, Katz, 0908.2991
Momentum dep. DM Scattering Chang, Pierce, Weiner, 0908.3192
Resonant Dark Matter Bai, Fox, 0909.2900
electro-magnetic DM interactions Masso, Mohanty, Rao, 0906.1979;
Chang, Weiner, Yavin, 1007.4200; Barger, Keung, Marfatia, 1007.4345; Fitzpatrick, Zurek,
1007.5325; Banks, Fortin, Thomas, 1007.5515
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 49
elastic spin-dependent (eSD) scattering
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 50
Spin-dependent scattering
coupling mainly to an un-paired nucleon:
neutron proton
DAMA 23
11Na even odd
DAMA, KIMS, COUPP 127
53I even odd
SIMPLE 35
17Cl, 37
17Cl even odd
XENON, ZEPLIN 129
54Xe, 131
54Xe odd even
CDMS, CoGeNT 73
32Ge odd even
PICASSO, COUPP, SIMPLE 19
9F even odd
CRESST A74
W, 16
8O, 40
20Ca even even
coupling with proton promising for DAMA vs CDMS/XENON
BUT: severe bounds from COUPP, KIMS, PICASSO, SIMPLE
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 51
eSD
Kopp, Schwetz, Zupan, 0912.4264
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 52
Constraints from Tevatron
assume effective quark DM interaction:
g
Λ2(qγ5γµq)(χγ5γ
µχ)
⇒ pp→ χχ+ j
constraints from mono-jet searches at Tevatronassume EFT is still valid at ∼TeV momentum transfer
e.g., Feng, Su, Takayama, hep-ph/0503117;
Beltran et al., 1002.4137; Goodman et al., 1005.1286; Bai, Fox, Harnik, 1005.3797;. . .
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 53
SD and constraints from Tevatron
Bai, Fox, Harnik, 1005.3797 T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 54
SD and constraints from Tevatron and neutrinos
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 54
SD and constraints from Tevatron and neutrinos
Interplay of direct det. / indirect det. / collider very powe rful
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 54
inelastic scattering (DAMA)Tucker-Smith, Weiner, hep-ph/0101138
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 55
Inelastic DM scattering
0 20 40 60 80 100E
recoil [keV]
even
t spe
ctru
m [
arb.
uni
ts]
δ = 0
δ = 50 keV
δ = 100 keV
δ = 150 keV
δ = 200 keV
mχ = 100 GeV scattering off Xenon
σ increased by factor 10 in each step for δ
mχ∗−mχ = δ ≃ 100 keV ∼ 10−6mχ
vinelmin =
1√2MER
(
MER
µχ
+ δ
)
• sampling only high-velocity tail of velocity distribution
• no events at low recoil energies
• high mass targets favoured ⇒ use iodine in DAMA butno explanation for GoGeNT, CRESST-O
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 56
iSI
talk by W. Seidel @ IDM 2010
mχ ≃ 50 GeV, δ ≃ 130 GeV
disfavored by CRESST (tungsten)
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 57
iSD on protons
inelastic spin-dependent scatteringKopp, Schwetz, Zupan, 0912.4264
0 5 10 15 20
-0.04
-0.02
0.00
0.02
0.04
0.06
E @keVD
S m@d-
1kg-
1ke
V-
1 D
DAMA annual modulation vs. iSD fit
Analysis window
mΧ = 44.7 GeV
Σp = 1.´10-32 cm2
∆ = 133 keVΧ2 = 5.24058
mχ ≃ 50 GeV, δ ≃ 130 GeVT. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 58
iSD on protons
• no tuning wrt to vesc needed
• SD coupling to proton gets rid of XENON/CDMS/CRESSTbounds (no unpaired proton)
• inelastic scatt. gets rid of PICASSO/COUPP (light target)
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 59
iSD on protons
• no tuning wrt to vesc needed
• SD coupling to proton gets rid of XENON/CDMS/CRESSTbounds (no unpaired proton)
• inelastic scatt. gets rid of PICASSO/COUPP (light target)
BUT:
• cannot explain CoGeNT/CRESST-O
• neutrino constraints from annihilations in the sundepend on annihilations channels (light quarks, µ, e still OK)Shu, Yin, Zhu, 1001.1076
• probably mono-jet bounds from Tevatron applyT. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 59
iSD - toy model
Kopp, Schwetz, Zupan, 09: generalize idea of Tucker-Smith, Weiner, 01 to SD int.:assume 4-Fermi interaction with T ⊗ T structure:
Lint =CT
Λ2
[
ψΣµνψ][
qΣµνq]
, Σµν = i[γµ, γν ]/2
ψ = (η, ξ†) with Dirac mψψ and Majorana mass (δηηη + δξξξ)/2
⇒ two Majorana fermions with masses m± δ (δη = δξ = δ ≪ m):
χ1 = i(η − ξ)/√
2, χ2 = (η + ξ)/√
2
⇒ ψΣµνψ = −2i(χ2σµνχ1 + χ†2σµνχ
†1) ,
• inelastic scattering for δ 6= 0• T ⊗ T leads to spin dependent scattering in the non-rel. limit
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 60
magnetic inelastic DM
observe that I, Cs, Na, F nuclei have very large effective MMassume DM has MM: L = µχ
2χ∗σµνχF
µν + h.c.
Chang, Weiner, Yavin, 1007.4200
• use large MM of iodine to enhance rate in DAMA• inelast kinematics avoids florine constraints (light target)• no explanation for CoGeNT/CRESST-O
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 61
Conclusions
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 62
Conclusions
There are a few hints in the low mass region, BUT:• mostly not consistent with each other• region(s) strongly constrained (excluded?) by
various bounds
⇒ we are speaking about a challenging region on theedge of the capabilities of detectors
⇒ experimental issues like quenching factors andthreshold effects are not yet well enough understood
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 63
Conclusions
maybe we are not seeing DM now,. . .
but this situation is typical for the DM field:any claimed signal has to be cross checked /re-discovered / excluded by several complementaryexperiments
similar situation as recent cosmic ray “DM signals”
at some point “hints” will converge (hopefully)!
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 64
Additional slides
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 65
iSI
vmin relevant for the DAMA signal is tuned exactly tothe galactic escape velocity:
0 100 200 300day
0
0.01
0.02
0.03
0.04
0.05
cnts
/ kg
/ d
/ keV
δ = 37.65 keVδ = 39 keV
mχ = 10.92 GeV, σ = 1.66e-38 cm2
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 66
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 67
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 68
iSD on protons - neutrino constraints
δ = 40 keV δ = 130 keV
Shu, Yin, Zhu, 1001.1076
constraints from SuperK on high-energy neutrinosfrom DM annihilations inside the sun
T. Schwetz, ITP Heidelberg, 14 Oct 2010 – p. 69
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