dark matter: thermal versus non-thermal bhaskar dutta...
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Bhaskar Dutta
Texas A&M University
Dark Matter: Thermal Versus Non-thermal
IACS, Kolkata, India
December 19, 2014
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Thermal and Non-thermal Dark Matter (DM)
Moduli Decay and DM
Baryogenesis from the Decay of Moduli
Necessary Conditions for Successful Models
Example of a moduli model
Dark Radiation (DR) and DM correlation
Example of visible sector model
Non-Thermal Scenarios at the LHC and Direct Detection Expt.Conclusion
Outline
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SM
Dark Energy68%
Atoms5%
Dark Matter27%
Important questions:
What is the origin of dark matter?
How does it explain the dark matter content?
Is there any correlation between baryon and dark matter abundance?
Questions
Consequences for:
Particle Physics Models
Thermal History of the Universe
Dark Matter: ThermalProduction of thermal non-relativistic DM:
ffDMDM
ffDMDM
Universe cools
ffDMDM
Boltzmann equation
][3 2,
2eqDMDMeqDM
DM nnvHndt
dn
6
/)(2
31
3
6
/)(2
31
3
)2(
)2(21
21
TEE
TEE
eq epdpd
vepdpd
vvolnostppfdgn /.
)2(),(
3
3
m/T
3* Tgn
snY
s
Y
Dark Matter: Thermal
Freeze-Out: Hubble expansion dominates over the interaction rate
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v1~DM c
DMDMnm
20~ DM
fmT
Dark Matter content:
Assuming : 2
2
~v
mf
ac~O(10-2) with mc ~ O(100) GeVleads to the correct relic abundance
m/T
freeze out
scm 3
26103v Y becomes constant for T>Tf
Nc G
H
83 2
0
Y
Thermal Dark Matter
Dark Energy68%
Atoms5%
Dark Matter27%
v1~DM
20~ DM
fmT
Dark Matter content:
Weak scale physics :
2
2
~v
mf
ac~O(10-2) with mc ~ O(100) GeVleads to the correct relic abundance
freeze out
scm 3
26103v WIMP
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Suitable DM Candidate: Weakly Interacting Massive Particle (WIMP)
Typical in Physics beyond the SM (LSP, LKP, …)
Most Common: Neutralino (SUSY Models)
Neutralino: Mixture of Wino, Higgsino and Bino
Dark Matter: Thermal
Larger annihilationcross-section
smaller annihilationcross-section
Larger/Smaller Annihilation Problem for thermal scenario
Status of Thermal DM
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LargeCross-section is constrained
: smaller than the thermal valueoannv
vann
Thermal DM 27%
Gamma-rays constraints: Dwarf spheroidals, Galactic center
Geringer-Sameth, Koushiappas’11, Hooper, Kelso, Queiroz, Astropart.Phys. ‘13
Experimental constraints:
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Latest result from Planck
http://public.planck.fr/images/resultats/2014-matiere-noire/plot_constraints_planck2014.jpg
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<sv>= a + b v2
Thermal Relic Density:At freeze-out, <sv> =3x10-26cm3/s
High b/a lowers the cross-section at small v (Present Epoch)For S wave domination, cross-section remains same (constant)
Dark matter annihilation cross-section:
Dark Matter Pair Annihilation
a, b are constants
If S wave is suppressed then the cross-section is dominated by P wave b v2>>a
<sv> is much smaller today compared to the freeze-out time
Annihilation cross-section can be larger today compared to theFreeze-out time due to Sommerfeld enhancement
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Natural SUSY and dark matter [Baer, Barger, Huang, Mickelson,
Mustafayev and Tata’12; Gogoladze, Nasir, Shafi’12, Hall, Pinner, Ruderman,’11;
Papucchi, Ruderman, Weiler’11],Higgs mass 125 GeV & Cosmological gravitino solution [Allahverdi, Dutta, Sinha’12]
Higgsino dark matterHiggsino dark matter has larger annihilation cross-sectionTypically > 3 x 10-26cm3/sec for sub-TeV mass
Thermal underproduction of sub-TeV Higgsino
LHC Constraints and Status of DMLHC constraints on first generation squark mass + Higgs mass:
Unnatural SUSY: Wino DM- Larger annihilation cross-section(for smaller wino mass)Arkani-Hamid, Gupta, Kapla, Weiner, Zorawsky’12
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Recent Higgs search results from Atlas and CMS indicatethat mh ~126 GeV
LHC status…
in the tight MSSM window <135 GeV
(1st gen.) ~ ≥ 1.7 TeV
For heavy ≥ 1.3 TeV
produced from , ≥ 700 GeV
produced directly, ≥ 660 GeV (special case)
excluded between 110 and 280 GeV for a mass-less or for a mass difference >100 GeV, small DM is associated with small missing energy
masses between 100 and 600 GeV are excluded for mass-less for or for the mass difference >50 GeVdecaying into e/m
qm~gm~
,~qm gm~
1~tm
1~tm
1~t
1~t
g~
~/~e 01
~
01
~
1~
1
~
Can lead to over production of relic abundance
Can lead to over production of relic abundance
Non-standard thermal history at is generic in some explicit UV completions of the SM.
fTfTT
Acharya, Kumar, Bobkov, Kane, Shao’08Acharya, Kane, Watson, Kumar’09Allahverdi, Cicoli, Dutta, Sinha,’13
Status of Thermal DMThermal equilibrium above is an assumption.
DM content will be different in non-standard thermal histories (i.e., if there is entropy production at ). fTT
Barrow’82, Kamionkowski, Turner’90
DM will be a strong probe of the thermal history after it is discovered and a model is established.
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Thermal, Non-thermal
: Large multicomponent/non-thermal; Small Non-thermal
LHC: Investigate colorless particles, establish the model
DM annihilation from galaxy, extragalactic sources
Annihilation into photons: Fermi, HAWC, H.E.S.S.
Annihilation into neutrinos: IceCube
Annihilation into electron-positrons: AMS
vann
Obtaining correct relic density for :
1) (thermal underproduction):
Multi-component DM (WIMP + non-WIMP)Example: mixed Higgsino/axion DM
Asymmetric DM (DM content can have large )
2) (thermal overproduction): DM from WIMP decay
Ex: Axino DM,
Gravitino DM
1326103 scmv fann
1326103 scmv fann
Baer, Box, Summy’09
Covi, Kim, Roszkowski ‘99
Feng, Rajaraman, Takayama’03
fannv Zurek’13
1326103 scmv fann
Beyond Thermal DM
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Non-Thermal DM
The moduli decay width: • start oscillating when H < mt• dominate the Universe before decaying
and reheating it
2
3
2 pMmc
Moduli are heavy scalar fields that acquire mass after SUSY breaking and are gravitationally coupled to matter Inflation
Radiation domination
modulidomination
radiationdomination
.
.
.
Decay of moduli
Dark Matter from Moduli decay:
m
Mm
cTp
r
2/1
2/1~
TeV50MeV3
mTT BBNr
e.g., Moroi, Randall’99; Acharya, Kane, Watson’08,Randall; Kitano, Murayama, Ratz’08; Dutta, Leblond, Sinha’09; Allahverdi, Cicoli, Dutta, Sinha,’13
For Tr<Tf: Non-thermal dark matter
m
TY r
43
Abundance of decay products
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Dark Matter from ModuliDM abundance
1. First term on the RHS is the “annihilation scenario”Requires:
Since Tr < Tf, we need wino/Higgsino DM
],.[min DMr
f
f
Th
f
obs
DMDM BrYTT
v
v
sn
sn
r
fth
fannfann TT
vv
th
fannfann vv
Gamma-rays constraints: Dwarf spheroidals, Galactic center MDM > 40 GeV, Tf < 30 TrTr > 70 MeV
2. Second term on the RHS is the “branching scenario”Can accommodate large and small annihilation cross-sections
Bino/Wino/Higgsino are all okYf is small to prevent the Br fDM from becoming too small (actually in realistic scenarios: Br ≥ 5 x10-3 => Tr< 70MeV)
(for mf~ 5 x106 GeV)
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Dark Matter from Moduli Decays dilutes any previous relics
Thermal DM gets diluted if Tr < Tf ~ mDM/20 ~ O(10) GeVAxionic DM gets diluted if Tr < LQCD ~ 200 MeV
(fa~1014 GeV is allowed for Tr ≥ TBBN) [Fox,Pierce,Thomas’04] Baryon asymmetry gets diluted if produced before f decay
Non-thermal DM Production from f decay
Annihilation scenario for Tr close to TfDM production with large cross-section: Wino/Higgsino
Branching scenario for smaller Tr(annihilation cross-section does not matter)
Baryon asymmetry from f decay ⇒ Cladogenesis of DM and Baryogenesis [Allaverdi, Dutta, Sinha’11]
Dark Matter from Moduli“Branching scenario” solves the coincidence problem
Baryon abundance in this model: BB BrYs
n
Yf appears in the DM abundance as well, Yf~ 10-7- 10-9
BRfB ~ 10-1-10-3 easy to satisfy for baryogenesis,e (one loop factor) ~ 10-1-10-2
For mDM ~ 5 mB, e BRfB ~ BRfDM nB ~ nDM
5111
DM
B
DMDM
B
DMDM
b
BrBr
mBrYBrY
m
W=r/rc; r=mn
The DM abundance and Baryon asymmetry are mostly saturated by Yf, Brs contribute the remaining not much particle physics uncertainty 19
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Baryogenesis from Moduli
NNM
XXMXddXuNW cj
ciij
ciiextra 2
'
: SM singlet; : Color triplet, hypercharge 4/3N XX , Baryogenesis from decays of or NXX ,
: can be the DM candidate : Allahverdi, Dutta, Mohapatra, Sinha’12N~
Nbb
B BrYs
nn
BrN : branching ratio of moduli decay to N
Assuming that N produces Baryon Asymmetry
e : asymmetry factor in the N decay
<0.1, BrN ~ 10-2 -1 B = 9x10-11,1010~ 79 Y
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Baryogenesis
From X decay
Typically, e1,2 is O(10-2) for CP violating phase O(1) and l~O(1)
Baryogenesis from Moduli
NN
MXXMXddXuNW c
jciij
ciiextra 2
'
Similarly, e2
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Conditions for ModelsTwo typical problems for moduli decay
Gravitino Problem:[Endo,Hamaguchi,Takahashi’06][Nakamura,Yamaguchi’06]
If m3/2<40 TeV Gravitino decays after the BBNmf>2 m3/2 can lead to DM overproduction
Large branching ratio of moduli into light Axions Neff
[Cicoli,Conlon,Quevedo’12][Higaki,Takahashi’12]
(at 95% CL) : Neff=3.52+0.48-0.45
)114
871(
3/4
effrad N
Current bound from Planck+WMAP9+ACT+SPT+BAO+HST
Large volume can be obtained after stabilization of
For large volume, one can have a sequestered scenario such that:
For example, TeV scale SUSY can be obtained for:
Balasubramanian, Berglund, Conlon, Quevedo’05
saTfluxbb AeWWTTK ,)ln(3
2/)( bbb TT
Cicoli, Conlon, Quevedo’08
)~( 22/32/3 bb
mmmmmm softsoft
TeVmGeVmGeVm softb1~,105~,10~ 610
2/3
Ex: NT DM in Large Volume Scenarios
No Gravitino Problem
3/2vis
3/2np
3/2b v
[Detailed Mass spectra, Aparicio, Cicoli, Kippendorf, Maharana, Quevedo’14
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The decay to gauge bosons arises at one-loop level:
The decay to Higgs controlled by the Giudice-Masiero term:
The decay to gauginos (and Higgsinos) is mass suppressed:
02/3 Br
2
32
4~
P
SMgg M
m
)ln(
23
b
2
2
~~
P
softgg M
mm
1Br
2
32
24 PHH M
mZdu
2/3mmb
LVS set up can successfully accommodate non-thermal DM.
NT DM in Large Volume Scenarios
Yf can be quite small ~ 10-10 : branching and annhilations are ok Allahverdi, Cicoli, Dutta, Sinha’13
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NT DM in Large Volume Scenarios
The 3 body decay width larger than the 2-body decay width of moduli into gauginos[ is suppressed by (mgaugino/mf)2 compared to ]
Yf ~ 10-10 (using mf~5 x 106 GeV)
YDM: Yf BRfDM ~ 10-12 mDM~ O(100) GeV is allowed
Solves the coincidence problem
If the dominant decay mode is to gauge boson final statesf decays into DM particle via 3-body: ggg ~~
310 DMBR
gg~~ gg
Since produces dark matter at the end of the decay chaing~
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DM-DR Correlation in LVS:The axionic partner of , denoted by is not eaten up by anomalous U(1)’s.
acquires an exponentially suppressed mass . is produced from decay:
Bulk axions are ultra-relativistic and behave as DR.
contribute to the effective number of neutrinos :
2
3
481
Paa M
mbb
b
Cicoli, Conlon, Quevedo’13
0bam
ba
baba
effN
2
3
48)(
P
totvis
Mmcc
vis
hideff c
cN7
43 )04.3( effeff NN
DM-DR Correlation
DM-DR Correlation
2
32
24 PHH M
mZdu
31 ZN eff
2
32
4~
P
SMgg M
m
bb aagg
48.045.048.0
effN
..chHZHKbb
du
Bound from Planck+WMAP9+ACT+SPT+BAO+HST at 95%
Decay to visible sector mainly produces gauge bosons and Higgs:
bbdu aaHHtot
We get a lower bound on Tr27
Pr
totvisr M
mm
TgCCT
4/1
* )(28851
75.22875.10)()(
*
gTeVOTMeVO r
DM-DR Correlation
2
3
2
3
24,
24 P
visvis
P
tottot M
mCMmC
22 21,2 ZCZC totvis
Using 4/14/1*
2 )]/(30[ visr gT
28
29
Br
mT
sn
Y r
43
66 10)(105~,3 YGeVOTGeVmZ r
Avoiding excess of DR within LVS prefers “Annihilation” scenario Higgsino-type DM.
obssn
sn
Br
3103
Abundance of DM particles produced from decay:
DM-DR Correlation
: Branching scenario does not work
: Branching scenario
DM-DR Correlation
fannfr v
scmTT
1326103
fann v
20~ m
T f
Obtaining the correct relic density in “Annihilation” scenario needs:
Assuming S-wave annihilation, which is valid for the Higgsino-type DM, is directly constrained by Fermi.
For Higgsino-type DM, using the b final state, the bound reads:
mGeV
GeVT r
1)18(
GeVm 40
Upper bound on Tr gets bounded from belowfann v 30
DM-DR Correlation
fannfr v
scmTT
1326103
20~ m
T f
Over production in the branching scenario
Allowed by the Fermi data in the annihilation scenario
GeVm 6105~
The Fermi bound is translated to constraint in plane: mNeff
Allahverdi., Cicoli, Dutta, Sinha’14
DM-DR Correlation
Pr
hidvisr M
mm
TgCCT
4/1
* )(28851
vis
hideff C
CN743
using
mNeff , : set lower bound on DM mass
6105m
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Model Examples: 2
2
21 SmXhSXW ss
f can be a visible sector field S (moduli is a hidden sector field)
S Decay + DM Annihilation or no annihilation works
ms~ O(1) TeV, mX~ O(10) TeV, mN~ O(0.5) TeV
W=Ws+WN,X
BRfDM ~ 10-6
Ys =(3/4)Tr/ms ~ 10-4
nDM/s ~ 10-10
Allahverdi, Dutta, Sinha, ‘13
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Model Example 2S Decay + Branching ratio Baryogenesis
~ 0.01
~
for (mN1/mX)
Ys =(3/4)Tr/ms ~ 10-4
~ 10-10
22
1
81
X
N
mm ~ 10-4
~ 10-2
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Cross Sections via VBFCross Sections via VBFNon-thermal Scenarios @LHCjjpp 0
10
1~~
CDM
Probe the DM sector directly: One interesting way:
Preselection:missing ET > 50 GeV, 2 leading jets (j1,j2) :pT (j1),pT(j2) >30 GeV|Dh(j1, j2)| > 4.2 and hj1hj2 < 0. Optimization: Tagged jets : pT > 50 GeV, Mj1j2 > 1500 GeV; Events with loosely identified leptons(l = e; m ; th) and b-quark jets: rejected. Missing ET : optimized for different value of the LSP mass.Delannoy, Dutta, Gurrola, Kamon, Sinha et al’13
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Non-Thermal scenario @ LHC
Final states at the LHCNew Particles: Heavy colored states:
LHC signals: new colored states -spin 0- are pair produced high ET four jets in the final statesnew colored states –spin ½- are pair produced, high ET four jets +missing energy
[via cascade decays into squarks etc]
Distinguishing Feature: 4 high ET jets and 4 high ET jets + missing energy
XX ,SM Singlet: N
NNM
XXMXddXuNW cj
ciij
ciiextra 2
'
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Non-Thermal scenario @ LHC
Dutta, Gao, Kamon’14
Monojet Dijet Dijet pair
If N is the DM candidate, i.e., mN~ mp
Dijet + Missing Energy
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DM via Monojet at LHC
Also, Mono-top, di-tops inthis model
Combining various observable, we can probe ann. cross-section
Monojet
Direct Detection
Direct detection scattering cross-section: cii XuN~
Scatters off a quark via s-channel exchange of XN~
For li~1, Mx~ 1 TeV,
Dark Matter Candidates: , NN ,~
~
Suppose: is the DM particle (spin-0) N~
If N (spin ½) is DM, MN~mp (to prevent N decay and p-decay), sN-p is 10-51cm2 (SI) and 10-42cm2 (SD)
• The origin of DM content is a big puzzleWe will be able to understand the history of the early universe
• Thermal DM is a very attractive scenario However, it contains certain assumptions about thermal history
• Alternatives with a non-standard thermal history are motivated Typically arise in UV completionsCan ease the tension with tightening experimental limits
• Non-thermal DM arising from moduli decay is a viable scenario can yield the correct density for large & small annihilation rates Successful realization in explicit constructions is nontrivial
Conclusion