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IN V E STIG A TIN G N E U TR A L IN O D A R K M A TTE R :IN V E STIG A TIN G N E U TR A L IN O D A R K M A TTE R :IN V E STIG A TIN G N E U TR A L IN O D A R K M A TTE R :IN V E STIG A TIN G N E U TR A L IN O D A R K M A TTE R :
A D A G IO S A N D PR E STO SA D A G IO S A N D PR E STO SA D A G IO S A N D PR E STO SA D A G IO S A N D PR E STO S
A lessandro B ottino A lessandro B ottino A lessandro B ottino A lessandro B ottino U niversità di Torino/IN F NU niversità di Torino/IN F NU niversità di Torino/IN F NU niversità di Torino/IN F N
TheTheTheThe D ark Side of the D ark Side of the D ark Side of the D ark Side of the U niverseU niverseU niverseU niverse 2006 2006 2006 2006 M adrid , M adrid , M adrid , M adrid , JuneJuneJuneJune 20202020----24, 2006 24, 2006 24, 2006 24, 2006
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Contents
• W hereW hereW hereW here do do do do w ew ew ew e stand stand stand stand w ithw ithw ithw ith neutralinoneutralinoneutralinoneutralino dark dark dark dark m atterm atterm atterm atter ????
• H intsH intsH intsH ints forforforfor relicrelicrelicrelic neutralinosneutralinosneutralinosneutralinos in in in in presentpresentpresentpresent resultsresultsresultsresults
fromfromfromfrom direct/direct/direct/direct/indirectindirectindirectindirect searchessearchessearchessearches ? ? ? ?
• The The The The rolerolerolerole of of of of astrophysicalastrophysicalastrophysicalastrophysical uncertaintiesuncertaintiesuncertaintiesuncertainties
• PerspectivesPerspectivesPerspectivesPerspectives
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Com biningCom biningCom biningCom bining data of W M A P (3 data of W M A P (3 data of W M A P (3 data of W M A P (3 yearsyearsyearsyears data) data) data) data) w ithw ithw ithw ith
sm allsm allsm allsm all----scalescalescalescale CM B dataCM B dataCM B dataCM B data
largelargelargelarge----scale scale scale scale structurestructurestructurestructure surveyssurveyssurveyssurveys
w eakw eakw eakw eak gravitationalgravitationalgravitationalgravitational lensinglensinglensinglensing
highhighhighhigh----redshiftredshiftredshiftredshift SupernovaeSupernovaeSupernovaeSupernovae
((((D .N .D .N .D .N .D .N . SpergelSpergelSpergelSpergel etetetet al., al., al., al., astroastroastroastro----phphphph/0603449) /0603449) /0603449) /0603449)
one can one can one can one can obtainobtainobtainobtain
12.008.0 2 ≤Ω≤ hCDM
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W ithin supersym m etric theories w ith RW ithin supersym m etric theories w ith RW ithin supersym m etric theories w ith RW ithin supersym m etric theories w ith R ----parity conservation, parity conservation, parity conservation, parity conservation,
the the the the neutralinoneutralinoneutralinoneutralino provides one of the m ost interesting realizations provides one of the m ost interesting realizations provides one of the m ost interesting realizations provides one of the m ost interesting realizations
of a of a of a of a cold dark m atter particlecold dark m atter particlecold dark m atter particlecold dark m atter particle (W IM P) w ith (W IM P) w ith (W IM P) w ith (W IM P) w ith
appropriate appropriate appropriate appropriate relic abundance relic abundance relic abundance relic abundance
sizeable sizeable sizeable sizeable ratesratesratesrates for d irect and indirect m easurem entsfor d irect and indirect m easurem entsfor d irect and indirect m easurem entsfor d irect and indirect m easurem ents
A convenient susy schem e is an A convenient susy schem e is an A convenient susy schem e is an A convenient susy schem e is an effective effective effective effective –––– MMMM inim al in im al in im al in im al
SSSSupersym m etric extension of the upersym m etric extension of the upersym m etric extension of the upersym m etric extension of the SSSStandard tandard tandard tandard MMMM odel at the odel at the odel at the odel at the
electrow eak scale electrow eak scale electrow eak scale electrow eak scale ---- w hat w e m ainly consider in this talk w hat w e m ainly consider in this talk w hat w e m ainly consider in this talk w hat w e m ainly consider in this talk
CDMΩ≈Ωχ
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Notice that no gaugino-mass unification is assumed
-
N eutralinoN eutralinoN eutralinoN eutralino relicrelicrelicrelic abundanceabundanceabundanceabundance
-
R elic A bundance for Cold Candidates (W IM Ps)
intann
2392
v
cm103
><×≈Ω
−
σχh
≡>< intannvσ therm altherm altherm altherm al averageaverageaverageaverage of of of of integrated from the decoupling tim e to the present integrated from the decoupling tim e to the present integrated from the decoupling tim e to the present integrated from the decoupling tim e to the present
epoch.epoch.epoch.epoch.
Cosm ologicalCosm ologicalCosm ologicalCosm ological boundboundboundbound::::
238intann
max2
CDM2
cm103.2v
13.0)(−×≥>
-
CosmologicalCosmological boundbound on on mmχχ
GeV 6 ≥χm
mχ (GeV)
analyticapproximation
for (Ωχ h2)min
Ωχh2
upper bound
on ΩCDM h2
A.BA.BA.BA.B., Donato, ., Donato, ., Donato, ., Donato, FornengoFornengoFornengoFornengo, , , , ScopelScopelScopelScopelhephephephep----phphphph/0304080/0304080/0304080/0304080
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CosmologicalCosmological boundbound on on mmχχ
GeV 6 ≥χm
mχ (GeV)
analyticapproximation
for (Ωχ h2)min
Ωχh2
upper bound
on ΩCDM h2
A.BA.BA.BA.B., Donato, ., Donato, ., Donato, ., Donato, FornengoFornengoFornengoFornengo, , , , ScopelScopelScopelScopelhephephephep----phphphph/0304080/0304080/0304080/0304080
physicalphysicalphysicalphysicalregionregionregionregion
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M uchM uchM uchM uch lighterlighterlighterlighter neutralinosneutralinosneutralinosneutralinos are are are are allow edallow edallow edallow ed in in in in N extN extN extN ext----totototo----M inim alM inim alM inim alM inim al
Supersym m etricSupersym m etricSupersym m etricSupersym m etric extensionsextensionsextensionsextensions of the Standard M odelof the Standard M odelof the Standard M odelof the Standard M odel ::::R . F lores, R . F lores, R . F lores, R . F lores, K .A .K .A .K .A .K .A . O live and D . O live and D . O live and D . O live and D . Thom asThom asThom asThom as, , , , PhysPhysPhysPhys. . . . L ett.L ett.L ett.L ett. B 263 (1991) 425B 263 (1991) 425B 263 (1991) 425B 263 (1991) 425
S.A . A bel, S . Sarkar and I.B . W hittingham , hepS.A . A bel, S . Sarkar and I.B . W hittingham , hepS.A . A bel, S . Sarkar and I.B . W hittingham , hepS.A . A bel, S . Sarkar and I.B . W hittingham , hep----ph/9209292ph/9209292ph/9209292ph/9209292
D .G . Cerdeno, C . H ugonie, D .E . L opezD .G . Cerdeno, C . H ugonie, D .E . L opezD .G . Cerdeno, C . H ugonie, D .E . L opezD .G . Cerdeno, C . H ugonie, D .E . L opez ----F ogliani, C . F ogliani, C . F ogliani, C . F ogliani, C . M unozM unozM unozM unoz and A .M . and A .M . and A .M . and A .M . TeixeraTeixeraTeixeraTeixera
hephephephep----phphphph/0408102/0408102/0408102/0408102
J. J. J. J. G unionG unionG unionG union , D . , D . , D . , D . H ooperH ooperH ooperH ooper, and B . , and B . , and B . , and B . M cE lrathM cE lrathM cE lrathM cE lrath , , , , hephephephep----phphphph/0509024/0509024/0509024/0509024
SaHaHaWaBa~~~~~
5)2(
04)1(
03)3(
21 ++++=χ
M SSM M SSM M SSM M SSM isisisis extendedextendedextendedextended bybybyby addingaddingaddingadding a new a new a new a new gaugegaugegaugegauge singletsingletsingletsinglet ch iralch iralch iralch iral superm ultipletsuperm ultipletsuperm ultipletsuperm ultiplet
---- specia l specia l specia l specia l featuresfeaturesfeaturesfeatures: : : :
a very light CPa very light CPa very light CPa very light CP ----odd H iggs boson odd H iggs boson odd H iggs boson odd H iggs boson
a 5a 5a 5a 5 ----com ponents neutralino (the com ponents neutralino (the com ponents neutralino (the com ponents neutralino (the usualusualusualusual 4 4 4 4 com ponentscom ponentscom ponentscom ponents + a + a + a + a singlinosinglinosinglinosinglino))))
A lsoA lsoA lsoA lso direct detection direct detection direct detection direct detection ratesratesratesrates forforforfor relicrelicrelicrelic neutralinosneutralinosneutralinosneutralinos are are are are sizeablysizeablysizeablysizeably enhancedenhancedenhancedenhanced
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N oticeN oticeN oticeN otice: the W IM P : the W IM P : the W IM P : the W IM P relicrelicrelicrelic density density density density m ightm ightm ightm ight bebebebe m uchm uchm uchm uch higherh igherh igherh igher thanthanthanthan
the standard one the standard one the standard one the standard one in in in in cosm ologicalcosm ologicalcosm ologicalcosm ological m odelsm odelsm odelsm odels w hichw hichw hichw hich im plyim plyim plyim ply anananan enhancem entenhancem entenhancem entenhancem ent
in the in the in the in the expansionexpansionexpansionexpansion rate of the rate of the rate of the rate of the U niverseU niverseU niverseU niverse at the W IM P at the W IM P at the W IM P at the W IM P decouplingdecouplingdecouplingdecoupling tim etim etim etim e
ThisThisThisThis isisisis the case the case the case the case forforforfor::::
---- Cosm ological m odels Cosm ological m odels Cosm ological m odels Cosm ological m odels w ithw ithw ithw ith a a a a kinationkinationkinationkination phasephasephasephase
(Salati, (Salati, (Salati, (Salati, astroastroastroastro----phphphph/0207396; R osati, /0207396; R osati, /0207396; R osati, /0207396; R osati, hephephephep ----phphphph/0309124)/0309124)/0309124)/0309124)
- D arkD arkD arkD ark----energy m odels based on energy m odels based on energy m odels based on energy m odels based on scalarscalarscalarscalar----tensor gravitytensor gravitytensor gravitytensor gravity
(Catena, F ornengo, M asiero, P ietroni and R osati, (Catena, F ornengo, M asiero, P ietroni and R osati, (Catena, F ornengo, M asiero, P ietroni and R osati, (Catena, F ornengo, M asiero, P ietroni and R osati, astroastroastroastro----phphphph/0403614)/0403614)/0403614)/0403614)
---- R andallR andallR andallR andall----SundrumSundrumSundrumSundrum DDDD ----branebranebranebrane m odelm odelm odelm odel
((((R andallR andallR andallR andall and and and and SundrumSundrumSundrumSundrum , P R L 83 (4690) 1999) , P R L 83 (4690) 1999) , P R L 83 (4690) 1999) , P R L 83 (4690) 1999)
F or F or F or F or constraints using cosm ic antiprotonsconstraints using cosm ic antiprotonsconstraints using cosm ic antiprotonsconstraints using cosm ic antiprotons,,,, see Schelke, Catena, see Schelke, Catena, see Schelke, Catena, see Schelke, Catena,
F ornengoF ornengoF ornengoF ornengo, M asiero and , M asiero and , M asiero and , M asiero and P ietroni, hepP ietroni, hepP ietroni, hepP ietroni, hep ----ph/0605287ph/0605287ph/0605287ph/0605287
-
enhancem ent of the relic abundance in a scalarenhancem ent of the relic abundance in a scalarenhancem ent of the relic abundance in a scalarenhancem ent of the relic abundance in a scalar----tensor gravity m odeltensor gravity m odeltensor gravity m odeltensor gravity m odel
C atenaC atenaC atenaC atena , , , , F ornengoF ornengoF ornengoF ornengo, M asiero, , M asiero, , M asiero, , M asiero, P ietroniP ietroniP ietroniP ietroni and R osati: astroand R osati: astroand R osati: astroand R osati: astro–––– ph/0403614ph/0403614ph/0403614ph/0403614
3nRY =
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D etection of D etection of D etection of D etection of relicrelicrelicrelic particlesparticlesparticlesparticles
-
WIMP direct WIMP direct measurementsmeasurements
annual-modulationeffect
χ χ
nuclear-recoil measurement
χ χγ,e+ dp,
PairPair annihilationannihilation in the in the halohalo
-
AnnihilationsAnnihilations takingtaking placeplace in the in the HaloHalo
χ + χ→
keep directionality
ν, ν
γ (continuum)
γ line (Zγ)
−
e+
searches for rare
components in cosmic raysp
2density) Wimp( ratesdetection ∝
D
if halo is clumpy, strong enhancement in signal
Bengtsson, Salati, SilkSilk, StebbinsBerezinsky, A.B., Mignola
-
for signals due to produced by WIMP self-annihilationsin the galactic halo
-- propagation and diffusion of the charged particles in the halo
-- evaluation of the secondary productions (background)
Detection Detection Detection Detection ratesratesratesrates dependdependdependdepend sensitivelysensitivelysensitivelysensitively on the on the on the on the followingfollowingfollowingfollowing propertiespropertiespropertiesproperties::::phase-space distribution function for the WIMPs in the galactic halo
-- deviations of the smooth component from the isothermal sphere
-- possible existence of streams and clumps
dpe ,,+
-
The elastic cross section is bounded
- from below by the cosmological upper
limit
- from above by the susy model
This generates a “funnel”
at low mass
Neutralino – nucleon cross sectionColor code
from now on:
● Ωχh2 < 0.095
×××× Ωχh2 > 0.095
Sensitivity lines for a NaI detector with a low energy threshold and a large exposure for various WIMP distribution functionsIn the galactic halo
AB, Donato, Fornengo and Scopel, hep-ph/0304080
-
The elastic cross section is bounded
- from below by the cosmological upper
limit
- from above by the susy model
This generates a “funnel”
at low mass
Neutralino – nucleon cross sectionColor code
from now on:
● Ωχh2 < 0.095
×××× Ωχh2 > 0.095
Sensitivity lines for a NaI detector with a low energy threshold and a large exposure for various WIMP distribution functionsIn the galactic halo
AB, Donato, Fornengo and Scopel, hep-ph/0304080
N eutralinoN eutralinoN eutralinoN eutralino----nucleusnucleusnucleusnucleus m ass m ass m ass m ass m atchingm atchingm atchingm atching
NaI
-
Neutralino – nucleon cross sectionColor code:
● Ωχh2 < 0.095
×××× Ωχh2 > 0.095
Extending the scatter plot tohigher neutralino masses
-
DAMA modulation region, likelyhood function values distant
more than 4 σ from the null result (absence on modulation)
hypothesis, Riv. N. Cim. 26 n. 1 (2003) 1-73, astro-ph/0307403
Exposure: about 108.000 kg day
Neutralino – nucleon cross sectionColor code:
● Ωχh2 < 0.095
×××× Ωχh2 > 0.095
Extending the scatter plot tohigher neutralino masses
-
Neutralino – nucleon cross section
CDMS
D. S. Akerib et al., astro-ph/0405033
(in astro-ph/0509259 the upper limit is
improved by a factor of 2.5 )
EDELWEISS
A. Benoit et al.,
Phys. Lett. B 545, 43 (2002)
Upper limits from direct searches
assumptions:
isothermal sphere,
v0=220 km/sec,
ρ0=0.3 GeV/cm3
-
Dependence of the upper bounds on the WIMP galacticdistribution function
B1 = non-isotropic velocity dispersionA0 = isothermal sphereC3 = axisymmetric spatial distribution
E xperim entalE xperim entalE xperim entalE xperim ental data data data data fromfromfromfrom
A keribA keribA keribA kerib etetetet al., al., al., al., astroastroastroastro----phphphph/0509259/0509259/0509259/0509259
-
annihilationrate R
2222 1
relic abundance
SignalsSignalsSignalsSignals due due due due totototo WIMP WIMP WIMP WIMP selfselfselfself----annihilationannihilationannihilationannihilation in the in the in the in the halohalohalohalo
subdominant here
at constant χm
χΩχCDMΩ
122
int
020
2 11)(χχ
χ
σσσ
ρρ
mv
v
mvR
ann
annann
loc ><>∝< 2
int
1><
∝Ωvannσ
χ
Thus the quantity0
2)( >< vannloc
σρρχ
is maximal at 1.0)( min ≅Ω=Ω CDMχ
236max0
2 10])[( cmvannloc
−≅>< σρρχ
202 1)(
χ
χ σρρ
mvR ann
loc
>
-
Antiprotons
-
Among the signals due to WIMP self-annihilation in the halo, those of antiprotons are the most constraining ones for relicneutralinos with masses in the range GeVmGeV 200 10 ≤≤ χ
maximal annihilationrate R
experimentalupper bound
χmGeV 200
above antiprotons from neutralino self annihilationare irrelevant (e.g. are dominated by secondary production) unless the halo is substantially clumpy
GeVm 200≈χ
a qualitative plot
-
M aurin, Taillet, D onato, Salati, B arrau, B oudoul, astro-ph/0212111
P ropagation and diffusion of cosm ic rays in the haloP ropagation and diffusion of cosm ic rays in the haloP ropagation and diffusion of cosm ic rays in the haloP ropagation and diffusion of cosm ic rays in the halo
-
A .BA .BA .BA .B ., D onato, ., D onato, ., D onato, ., D onato, F ornengoF ornengoF ornengoF ornengo and Salati: and Salati: and Salati: and Salati: hephephephep----phphphph/0507086/0507086/0507086/0507086
effectseffectseffectseffects due due due due totototo light light light light neutralinosneutralinosneutralinosneutralinos can can can can bebebebe sizeablesizeablesizeablesizeable, , , , butbutbutbut hardlyhardlyhardlyhardly distinguishabledistinguishabledistinguishabledistinguishable
fromfromfromfrom background background background background
constraints constraints constraints constraints relaxedrelaxedrelaxedrelaxed bybybyby astrophysicalastrophysicalastrophysicalastrophysical uncertaintiesuncertaintiesuncertaintiesuncertainties of of of of prim aryprim aryprim aryprim ary fluxesfluxesfluxesfluxes
-
10 GeV 20 GeV30 GeV
Diffusion in a two-zones halo: - energy-dependent coefficient- L = halo thickness parameter
)(0 rigidityRRKK ==δβ
Com patibility am ong the W IM P and the astrophysical param etersCom patibility am ong the W IM P and the astrophysical param etersCom patibility am ong the W IM P and the astrophysical param etersCom patibility am ong the W IM P and the astrophysical param eters
A .B ., D onato, F ornengo, Salati, hepA .B ., D onato, F ornengo, Salati, hepA .B ., D onato, F ornengo, Salati, hepA .B ., D onato, F ornengo, Salati, hep ----ph/0507086 ph/0507086 ph/0507086 ph/0507086
-
The Gamma-rays Saga
-
Cesarin iCesarin iCesarin iCesarin i, , , , F ucitoF ucitoF ucitoF ucito , L ionetto, , L ionetto, , L ionetto, , L ionetto, M orselliM orselliM orselliM orselli, , , , U llioU llioU llioU llio , , , ,
astroastroastroastro----phphphph/0305075/0305075/0305075/0305075
EGRET excess from the Galactic Center
A .BA .BA .BA .B ., D onato, ., D onato, ., D onato, ., D onato, F ornengoF ornengoF ornengoF ornengo , , , , ScopelScopelScopelScopel, , , , hephephephep----phphphph/0401186/0401186/0401186/0401186
Explanation in terms of neutralino self-annihilation possible, but not compelling (boost factor required)
-
Elsasser and Mannheim: astro-ph/0405235
Extragalactic gamma-ray background
best fit: GeVm 11075515+−=χ
Important caveats:- the background is affected by large uncertainties- such a sizeable primary flux would imply violation of observationalbounds on gamma-ray flux from the Galactic Center (S. Ando, astro-ph/0503006)
-
EGRET excess of diffuse galactic gamma-rays fluxes
Analysis by de Boer, Sander, Zhukov, Gladyshev and Kazakov of the EGRET data in 180 independent sky directionsClaims: - the common spectral shape of the excess singles out a WIMP mass ~ 60 GeV- the flux of the excess determines a halo dark matter distribution in good
agreement with rotation curve
But ...
-
Conclusions by de Boer at al. contradicted by Bergstrom, Edsjo, Gustafsson and Salati, astro-ph/0602632:
the peculiar features of the dark matter distribution used by de Boer et al. difficult to achieve with non-dissipative dark matter and may have problemswith the disc surface mass density
the ensuing antiproton fluxes would overshoot the observational data
-
J. Albert et al (MAGIC Collaboration, astro-ph/0512469
High energy gamma-flux from the Galactic Center
Aharonian et al (HESS Collaboration) astro-ph/0408145
Power-law spectrum with an index
15.009.02.2 ±±−=α
-
The TeV radiation is well explained by astrophysical processes (Aharonian and Neronov, astro-ph/0503354)
Zaharijas, Hooper, astro-ph/0603540
Hard to disentangle a signal due to WIMP self-annihilation
-
Signals from dwarf galaxies satellites of the Milky Way: the case of Draco - good prospects for GLAST and MAGIC in case of favorable neutralino schemes :
Bergstrom and Hooper, hep-ph/0512317
See also: Profumo and Kamionkowski, astro-ph/0601249
-
The sensitivities of present direct and indirect WIMP searches already allow investigation of some interestingregions of the neutralino parameter space
Main challenge - to reduce some large uncertaintiesaffecting the astrophysical aspects: WIMP distributionfunction, propagation and diffusion properties of CRs, ...
In view of these uncertainties the interpretation of experimental data requires a conservative approach
Among the signals due to WIMP self-annihilation in the halo,the antiprotons are the most powerful signal for
Gamma-rays very intriguing – but great caution is needed before drawing strong conclusions
Independent information from accelerators is desperately needed
Conclusions
GeVm 200≤χ