they constitute hot dark matter, and their abundance is known. Dark matter must
be some particle state not contained in the SM: NEW PHYSICS NEEDED! 2 ...
Neutralino dark matter Howard Baer University of Oklahoma
1
Evidence for dark matter: overwhelming, and from numerous disparate sources! Properties: massive, neutral, cold (warm...) Of particles in the Standard Model (SM), only neutrinos have the right properties: but they constitute hot dark matter, and their abundance is known Dark matter must be some particle state not contained in the SM: NEW PHYSICS NEEDED!
2
Some dark matter candidates: mass vs. interaction strength plane Some Dark Matter Candidate Particles 10
24 21
10 10 10 10
18 15
12
Q-ball
9
10
6
Black Hole Remnant
10
3
10
0
-3
10
neutrinos
-6
neutralino KK photon branon LTP
10
-9
10
-12
10
10 10
-15 -18
10
-21
axion
-24
10
10
axino SuperWIMPs :
-27
-30
10
10
WIMPs :
wimpzilla
!int (pb)
10
-33
fuzzy CDM
gravitino KK graviton
-36
10
-39
10
-33
-30
-27
-24
10 10 10 10
-21
-18
-15
-12
10 10 10 10
-9
-6
10 10 10
-3
0
3
6
9
12
15
18
10 10 10 10 10 10 10
mass (GeV)
3
While some candidates are conjured by theorists specifically to solve the DM problem, others emerge as by-products of solutions to long standing problems in particle physics: Peccei-Quinn solution to strong CP problem: axions Supersymmetry: at least 3 viable DM candidates: neutralino, gravitino, axino/(axion)
4
SUSY motivations: naturalness in quantum field theory (no quadratic divergences for scalar fields) means to unification with gravity (supergravity) gauge coupling unification provided superpartners at TeV scale precision EW corrections and Higgs mass radiative EWSB and the top mass accommodate baryogenesis: at least 3 ways
5
Supersymmetric models: how SUSY breaking is communicated from hidden sector to visible sector gauge mediation (GMSB): solves SUSY flavor problem, contains very light gravitino: does not naturally yield CDM anomaly mediation (AMSB): mAMSB, HCAMSB, inoAMSB: solves flavor problem; need additional sources of CDM since thermal abundance too low gravity mediation (SUGRA): 3 (or more) ˜ a/˜ candidate DM particles: Z!1 or χ, G, a
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Simplest: mSUGRA or CMSSM embed MSSM into SUGRA gauge theory SUSY breaking in simple hidden sector parameter space: m0 , m1/2 , A0 tan β, sign(µ)
7
Neutralino: a WIMP DM candidate
The WIMP miracle 8
Calculation of relic density
9
mSUGRA parameter space well-known regions: *bulk (low m0, mhf) *stau co-annihilation (low m0) *HB/FP (large m0) * A resonance (large tan(beta) * stop co-ann. * h-resonance HB, Mustafayev, Park, Tata 10
More general: scan over 19 parameter SUGRA model Ωχ h too large for bino; too small for wino/ higgsino 2
mχ < 500 GeV HB, Box,Summy, arXiv:1005.2215
Ωχ h ∼ 0.11 2
is most unlikely value! 11
Non-standard cosmology may be Standard! neutralino production from moduli decay extra entropy production from moduli decay neutralino production from gravitino decay neutralino production from axino decay entropy production from axino decay axino or gravitino as LSP presence of axion component to DM 12
Too much relic density? Dilute with additional entropy production (Lazarides, Schaeffer, Seckel and Shafi, NPB346 (1990) 193), or assume χ decay to lighter states e.g. axino or gravitino (Covi, Kim, Kim, Roszkowski, JHEP0105 (2001) 033)
Too little relic density? Add more via production from moduli/gravitino/axino decay: (Randall, Moroi, NPB570 (1999) 1731; Acharya, Kane, Watson, Kumar, PRD80 (2009)083529
Gelmini, Gondolo, PRD74 (2006) 023519 13
Production of SUSY (dark) matter at LHC7:
√
s = 7 T eV 14
Simulated production of neutralino DM from SUSY at LHC
15
Search for mSUGRA at LHC
16
SM backgrounds to SUSY
17
Optimize cuts over parameter space
Then require, for some set of cuts and integrated luminosity:
18
Reach of LHC7 for various integrated luminosities:
HB, Barger, Lessa, Tata: JHEP 19
Smoking gun signature for LHC7: OS/SF dileptons Models with gaugino mass unification
mZ˜2 − mZ˜1 < MZ i.e.
mg˜ < 630 GeV dilepton mass edge below MZ!
20
Reach of LHC14 compared to Tevatron and ILC
21
Precision sparticle measurements at LHC
22
Precision SUSY measurements and cosmology Find which parameter space choices lead to precision measurements Map parameters onto e.g. relic density, DD cross section, ID -> Collider measurement of
Ωχ h , σ(χp), !σ · v", · · · 2
Allanach, Belanger, Boudjema, Pukhov Nojiri, Polesello, Tovey Baltz, Battaglia, Peskin, Wisansky Arnowitt, Dutta, Kamon, ..
Beware: points chosen are SPS1a or accessible to ILC500 23
IDD via neutrino telescopes
IDD via WIMP annihilation to gammas or antimatter 24
Direct WIMP detection via WIMP-nucleon scattering
25
DD in mSUGRA model: Xenon-100 should cover FP region!
26
Reach of LHC14, ILC compared to DD/ID WIMP search
HB, Park, Tata 27
Well-tempered neutralinos Arkani-Hamed, Delgado, Giudice
Scan over 10 models with and without universality; keep only models with correct relic abundance Bulk of models asymptote at 10^-8 pb! Accessible to next Xenon-100 run! HB, Mustafayev, Park, Tata 28
DD of relic winos in various AMSB models HB, Dermisek, Rajagopalan,Summy: JCAP 1007 (2010) 014
*unlike SUGRA models, these are bounded from below *reach of Xe 1 ton well beyond that of LHC 29
If a WIMP signal is found, do we declare victory and go home? NO! Era of WIMP astronomy will have just begun! Check SI scattering on different target nuclei (A^2 dependence) Extract WIMP mass from recoil E distribution Check SD WIMP scattering rate; sensitive to spin of WIMP Extract WIMP velocity distribution Directional detectors: seasonal, day/night eff. 30
If WIMP seen in DD, then mass measurement
Study by Schnee; Green; Drees&Shan shows m(WIMP) may be extracted from energy spectrum in DD experiments, for lower range of WIMP masses: crucial input for LHC? 31
Role of SI vs. SI WIMP search
Bertone, Cerdeno, Collar, Odom, PRL99 (2007)151301 32
Directional WIMP recoil detectors ala DRIFT
WIMP wind seasonal day/night 33
Gravitino production in early universe (gravitino problem) Gravitinos can be produced thermally in early universe Gravitino lifetime suppressed by M_Pl^-2 Late decays disrupt successful BBN predictions Need either m_grav > 5 TeV or T_R10^6 GeV Affleck-Dine leptogenesis: can have TR~10^6 GeV ....
35
Gravitino (superWIMP) dark matter:
BBN constraints on gravitino as LSP are severe unless it is very light, as in GMSB
(Case of bino NLSP)
Kawasaki, Kohri, Moroi, Yatsuyanagi, PRD78, 065011(2008) 36
Axion dark matter
Axion DM: forms BEC, suppresses small scale structure, gives mechanism for galactic rotation Sikivie, Wang arXiv:0901.1106 37
Axion microwave cavity seach
38
Axions+ SUSY=> axinos axino is spin-1/2, R-odd spartner of axion axino mass is model dependent: keV-> GeV axino is an EWIMP; coupling suppressed by 9 12 Peccei-Quinn scale fa : 10 − 10 GeV good candidate for cold DM for review, see Covi, Kim, Kim, Roszkowski JHEP 0105 (2001) 033
39
Peccei-Quinn + SUSY Two scenarios: Axino is LSP DM is mixture of axions plus thermally produced and non-thermal (decay produced) axinos no WIMP signals
Axino is not LSP: * DM consists of WIMP+axion mixture: TeV scale axinos decay to WIMPs, augmenting production as in AMSB models *Possible DD of WIMP and axion! 40
Conclusions: SUSY neutralino is excellent candidate for CDM Role of LHC: produce matter states associated with dark matter; decay to stable DM candidate (LHT, UED, SUSY, etc) usually gives ETMISS signature (charged stable NLSP counter-example) In case of WIMP dark matter, additional signals from DD/ID of DM will provide complementary information (e.g. WIMP mass?) Xenon-100 will soon test FP region of mSUGRA and well-tempered neutralino models with mixed bino-higgsino CDM precision measurements may allow collider measurement of relic density, associated quantities If WIMP signal is found, era of WIMP astronomy will begin! A-dependence; recoil spectrum; SD scatter; WIMP mass/velocity dist’n; directional detectors;compare to LHC; IDD signals;... DUSEL will be essential for program of WIMP astronomy! 41
