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Supersymmetric Dark Matter. Shufang Su • U. of Arizona. K. Olive, astro-ph/0301505. » 0.02 baryon. Baryonic dark matter ( lum » 0.003). Hot dark matter: Neutrino Cold dark matter WIMP axions Other possibilities self-annihilating DM self-interacting DM warm DM

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## Supersymmetric Dark Matter

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**Supersymmetric Dark Matter**Shufang Su • U. of Arizona K. Olive, astro-ph/0301505**» 0.02 baryon**Baryonic dark matter (lum» 0.003) • Hot dark matter: Neutrino • Cold dark matter • WIMP • axions • Other possibilities • self-annihilating DM • self-interacting DM • warm DM • fuzzy CDM • … 0.1 - 0.3 Non-baryonic dark matter » 0.7 Dark Energy , quintenssence,… Composition of the Universe - We know how much, but no idea what it is.**WIMP CDM**- • requirements Stable • lifetime ¸ 10 Gyr Non-baryonic Neutral:color (strong interaction) and electric • strong upper limits on the abundance of anomalously heavy isotopes Cold: non-relativistic Yield correct density WIMP • weak interacting: » 0.01, mW» 100 GeV » 0.1**Not for cosmology observations**• Dark Matter • Cosmology constant • Baryon asymmetry … Standard Model - SM is a very successful theoretical framework that describes all experimental observations to date =g2/4**Standard Model**- CDM requirements Stable Non-baryonic Neutral Cold Correct density No good candidates for CDM in SM**H**- 2 precise cancellation up to 1034 order -(1019 GeV)2 (1019 GeV)2 Supersymmetry Spin differ by 1/2 SM particle superpartner Naturalness ms-particle» O(100-1000) GeV Supersymmetry - SM is an effective theory below some energy scale Hierarchy problem:MEW100 GeV , Mplank 1019 GeV ? Naturalness problem: mass of a fundamental scalar (like Higgs) receive huge quantum corrections: (mH2)physical (mH2)0 + 2 (100 GeV)2 H**Gauge Coupling Unification**- SM SUSY**Minimal Supersymmetric Standard Model (MSSM)**- Spin differ by 1/2 SM particle superpartner » » » CDM requirements » » » Stable » » » Non-baryonic Neutral » » » Cold » » » m > 45 GeV » Correct density » » » » weak interaction**odd**odd - d ~ - s P - u s K+ u u MSSM DM Candidates - • Possible DM candidates • sneutrino • neutralino (B0,W0,Hd0,Hu0) ! i0 ~ ~ ~ ~ ~ Stable ? General MSSM, including B,L-violating operators - • dangerous introduce proton decay p ! K+ • R-parity SM particle: even + superparticle: odd - • no proton decay • lightest supersymmetric particle (LSP) stable LSP SM particle, LSP super particle • Good candidate of DM: could be or 10 ~**/l**W/Z /l/q Z ~ ~ ~ ~ ~ ~ /l/q /l W/Z ~ f Sneutrino Dark Matter - rapid annihilation, hAvi large • light sneutrino: 45-200 GeV low abundance • heavy sneutrino: 550 – 2300 GeV 0.1 1 • disfavored on theoretical ground • excluded by nuclear recoil direct detection: m¸ 20 TeV ~ Sneutrino CDM in MSSM is excluded**~** f W,Z H f Neutralino - ~ ~ ~ ~ B0, W0, Hd0, Hu0 Superpartner of gauge bosons Superpartner of Higgs bosons • Properties • fermion • neutral • heavy: m > 45 GeV • (B0, W0, Hd0, Hu0) neutralinos i0, i=1…4 mass eigenstates • Interactions: weak interacting / gauge coupling ~ ~ ~ ~**~**~ ~ ~ i0=i B0+ i W0+i Hd0 +i Hu0 , m1 m2 m3 m4 , 1 being LSP ~ M1< M2, ||: B0 Bino-LSP M2< M1, ||: W0 Wino-LSP ||< M1, M2: Hu0§ Hd0 Higgsino-LSP ~ ~ ~ Lightest Neutralino CDM - Now let us focus on neutralino as a candidate for CDM • Neutralino mass matrix Input parameter: M1, M2, , tan For small mixing: mZ¿ M1, M2, **common scalar mass**common gaugino mass common trilinear scalar m0 M1/2 A0 tan sign GUT scale Low energy MSSM parameters LSP ||,b replaced by mZ, tan MSSM Parameters - • Interactions involve the whole set of MSSM parameters > 100 new parameters (SM: 19 parameters) • other experimental constraints Simplest assumption (unification) CMSSM (constrained MSSM)**Relic Density**- Thermal relic density Decoupling: =nhvi¼ H >H ! X+Y • early time n ¼ neq • late time (n/s)today» (n/s)decoupling • at freeze-out T » m/20 <H n/s Approximately, relic/ 1/hvi**f**W + ~ ~ 10 10 10 10 10 10 W f ~ ~ f absent for B0 /l/q Z,H /l/q <v> = a+bx+… x=T/m Neutralino Relic Density (I) - • t-channel • (dominate) • s-channel Important near pole m» mZ,H/2 Relic Density:=hAvi n » H Special cases: • Co-annihilation:mLSP¼ mNLSP • Annihilation near a pole: e.g.m» mZ,H/2**Neutralino Relic Density (II)**Focus point m» mA.H/2 m=mZ,h/2 ~ Co-annihilation 10-l bulk - No EWSB 0.1 h2 0.3 CMSSM stau LSP**Phenomenological Constraints** b s me=99GeV ~ - • Other constraints • Higgs mass mh > 114.4 GeV • b ! s : » 10-4 exclude small m1/2 important for <0 • muon g-2 th-exp=(26 § 16)£ 10-10 muon g-2 m= mZ,h/2 region already excluded b ! s **Bulk region and -l coannihilation region**~ m» m +X ! +Y in equilibrium decays into eventually Co-annihilation:, , ~ ~ ~ ~ ~ ~ co-annihilation mB» 200 GeV ~ - mh bulk if ignore co-annihilation hvi» 1/m2, / m/hvi upper bound on m**Funnel-Like Region**Large tan : m» mA,H/2 /l/q A,H ~ ~ 10 10 /l/q - A,H: heavy Higgses SM: h0 MSSM: h0,H0,A,H§ / 1/hvi hvi» 1/(4m2 – mA,H2)2 too big too small**Focus Point Region**(100 GeV)2 - Co-annihilation, funnel and focus point regions are very fine-tuned Highly depend on the other input parameters ~**Direct Detection of DM**• Direct detection via neutralino-nucleon scattering • DM low velocity, non-relativistic • Spin-dependent:i q i q Mspin/pqh Spi/ JN + nqh Sni/ JN • Spin-independent: q mq q / mW Mscalar/ Z fp+ (A-Z) fn / 1/mq2 ~ - - - • Bino DM: no diagram 1 require small m0 • Bino-Higgsino DM large m0 detectable ,Z**Neutralino-Nucleon Scattering (II)**- 2 £ 10-10 pb SI 6 £ 10-8 pb 2 £ 10-7 pb SD 10-5 pb**DAMA and CDMS**- CDMS DAMA • DAMA finds signal in annual modulation as earth passes through WIMP wind • CDMS andEdelweiss excludes much of the favored region Edelweiss NUHM CMSSM pb = 10-36 cm2**Indirect Detection** - DM annihilation products from the Sun, Earth, galaxy require hard annihilation products (not good for Bino DM) • from the core of the Earth and Sun • e+ from the local solar neighborhood • from the Galactic center Under-ice, underwater neutrino telescopes Anti-matter/ anti-particle experiments Atmospheric Cherenkov telescopes, space-based ray detectors**Comparison of pre-LHC SUSY Searches**- • DM searches are complementary to collider searches • When combined, entire cosmologically attractive region will be explored before LHC ( » 2007 )**Conclusion**- • DM is the one of the strongest phenomenological motivation for new physics • Fruitful interplay of particle physics, cosmology, and astrophysics • A fascinating time: we know how much, but have no idea what it is • Many, many experiments • MSSM neutralino LSP is a good candidate for CDM • In SUSY, DM searches are promising, highly complementary to collider searches

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