DARK MATTER: direct and indirect detection Fiorenza Donato Dip. Fisica Teorica, Un. Torino & INFN IFAE, Perugia 27.04.2011

Neutralino as the CDM candidate Stable (if R-parity is conserved) Mass: m~ 10-1000 GeV Non-relativistic at decoupling  CDM Neutral & colourless Weakly interacting (WIMP) Good relic density h2 mh2=0.1120±0.0056 bh2=0.02249±0.00054 (WMAP07-Komatsu et al. ApJS2011) m ~ 0.226  ~ 0.729 (WMAP07&BAO&SNIa)

Which Supersymmetric Model? Theoretical and experimental constraints are too faint to outline a model Minimal Supersymmetric extension of the Standard Model (MSSM) depends on the SYMMETRY BREAKING mechanism: Gravity mediated  neutralino DM Gauge mediated  gravitino DM Anomaly mediated  neutralino, stau sneutrino The nature and phenomenology of LSP depends on susy breaking and regions of the susy parameter space

Effective MSSM scheme (effMSSM) (Model parameters defined at the EW scale) Independent parameters: M1 U(1) gaugino soft breaking term M2 SU(2) gaugino soft breaking term μ Higgs mixing mass parameter tan β ratio of two Higgs v.e.v.’s mA mass of CP odd neutral Higgs boson mq soft mass common to all squarks ml soft mass common to all sleptons A trilinear parameter R ≡ M1/M2 (=0.5 in GUT) Experimental Bounds - Accelerator (LEP & Tevatron) data on Higgs and supersymmetric particle (negative) searches b s - BSμ+ μ- - am≡(gm-2)/2 Requirements that neutralino is the LSP No a priori on the relic density h2 Subdominant neutralinos, if detectable, could be very interesting for particle physics (new physics) and cosmology (mixture of candidates)

SIGNALS from RELIC WIMPs Direct searches: elastic scattering of a WIMP off detector nuclei Measure of the recoil energy Indirect searches: in CRs signals due to annihilation of accumulated in the centre of celestial bodies (Earth and Sun)  neutrino flux signals due to annihilation in the galactic halo  neutrinos  gamma-rays  antiprotons, positrons, antideuterons N.B. New particles are searched at colliders But we cannot say anything about DM candidates!

Direct detection rate NT, A, mN: nucleus properties m: nucleus-neutralino reduced mass 1. r0,c: local (solar neighborhood) CDM density ASTROPHYSICS f(w): WIMP velocity distribution in the MW halo 2. s elastic cross-section = min(1, Wch2/(WCDMh2) PARTICLE PHYSICS 3. F(ER) NUCLEAR form factor (scalar) nucleon N. B. Neutrons behave as WIMPS – most insidious background

The very DM signature: the annual modulation Residual rate for single hit events December June 0.82 ton year total exposure @ LN Gran Sasso (INFN) DAMA/NaI & DAMA/Libra exp. Reported a positive evidence for a modulated signal 8.2s C.L. Bernabei et al. Eur. Phys. J. C 2010

Interpretation of direct detection results with the Torino code in effMSSM No-channeling Channeling Red region: DAMA annual modulation (with astroph. uncert.) Scatter plot: reference effMSSM (red: WMAP ok) Shaded blue: effMSSM with hadronic uncertainties

CDMS Experiment (Ge) Ahmed at el. PRL 2009; PRL 2011 PRL 2009: 2 events @12.3 and 15.5 keV (23% bkgd): Bottino, FD, Fornengo, Scopel PRD 2010 DAMA & CDMS 2 events & theory compatible 8-12 GeV neutralino BUT in PRL 2011: reanalysis Lower energy threshold  NO candiate events

CoGent Experiment (Ge) Aalseth et al. PRL 2011 WIMP contribution incompatible with 0 @ 90%CL Null WIMP Hypothesis ________________________________________________________ CRESST Experiment (CaWO4) W. Seidel, IDM 2010 32 events on Oxigen: “Background estimate of 8.7 ± 1.4 events not enough to explain 32 signals”

Liquid Xenon Set stringent limits Light-yield function: crucial Xenon100(Aprile et al 2011) Set stringent limits Xenon10 (Angle et al. 2011) Light-yield function: crucial Near energy threshold

Experiments and Models Bottino, Fornengo, Scopel PRD 2011 1 strong effect (Dama) + other hints: A1, A2: DAMA (B: CDMS 2 events) C: CoGent D: Cresst Red (WMAP ok) & Blue dots: MSSM Light neutralinos agrees well with Dama & with all other hints & cosmology & accelerator data

The actual situation is of great interest and new results The direct detection experiments have exciting results It is difficult to reconcile (strong or weak) WIMP evidences with exclusions from other experiments. Uncertainties in the halo shape, velcoity distribution function and escape velocities are not sufficient. (see T. Schwetz arxiv:1011.5432, Kopp et al.) Several experimental points need further study and checks. The actual situation is of great interest and new results are expected in the near future: stay tuned!

NEUTRALINO INDIRECT SIGNALS Annihilation inside celestial bodies:  at n telescopes as up-going m’s Annihilation in the galactic halo:  -rays - diffuse, monochromatic line, radio  and g keep directionality can be detected only if emitted from high c density regions Charged particles diffuse in the galactic halo antimatter searched as rare components in cosmic rays (CRs) ASTROPHYSICS OF COSMIC RAYS!

2-zone Semi-analytic Diffusive Model Maurin, Donato, Taillet, Salati ApJ 2001; Maurin, Taillet, Donato A&A 2002 Strong & Moskalenko ApJ 1998; Strong, Moskalenko, Ptuskin astro-ph/0701517 (Galprop) +All the effects included (VA0 & VC0) +2D semi-analytic + Local Bubble for radioactives - ISM constant VC constant througout the halo VA in the disk Diffusion coefficient K(R)=K0bRd Convective velocity Vc Alfven velocity VA Diffusive halo thickness L Acceleration spectrum Q(E)=pa K0, d, Vc, VA, L, (a) Systematic scan of parameter space Evaluation of uncertainties

ANTIPROTONS IN COSMIC RAYS Donato, Maurin, Salati, Barrau, Boudoul, Taillet, et al, ApJ 2002 ; ApJ (2001); BergstrÖm, EdsjÖ, Ullio, ApJ (1999); Bieber et al. PRL (1999); Moskalenko et al., ApJ (2002); Donato, Maurin, Brun, Delahaye, Salati PRL2009 PCR + HISM PCR + HeISM p- + X aCR + HISM aCR + HeISM Diffusion Measured fluxes Nuclear cross sections Diffusion model tested on B/C Maurin, Taillet, Donato A&A 2002 Putze, Derome, Maurin A&A 2010

Antiproton/proton: data, models, exotic tips Theoretical calculations with the semi-analytical DM, compatible with stable and radioactive nuclei Donato, Maurin, Brun, Delahaye, Salati PRL 2009 PROTON flux: Φ=Aβ-P1R-P2 T<20 GeV: Bess 1997-2002 (Shikaze et al. Astropart. Phys. 2007) T>20 GeV, our fit (Bess98, BessTeV&AMS): {24132; 0; 2.84} NO need for new phenomena (astrophysical / particle physics)

Antideuteron Signal-to-Background Antideuterons in Cosmic Rays FD, Fornengo, Salati PRD 2000; FD, Fornengo, Maurin PRD 2008 Antideuterons may form by the fusion of an antiproton and an antineutron Antideuteron Signal-to-Background MAX MED MIN m=50 GeV Dashed: MED m=10 m=100 m=500 Low energy antideuterons have a high discrimination power

ANTIDEUTERONS & future experiments effMSSM neutralino dark matter can be detected by means of next generation space instruments measuring antideuterons in CRs

MSSM Inspections with Antideuterons GAPS ULDB reach Median propagation Parameters Red: dominant neutralinos Blue: sub-dominant neutralinos

Constraints on Dark Matter contribution from positron/electron data Donato et al. PRL 2009 Example: m=1 TeV, WW fit improves, but highest points in E not explained High boost factor required  ONLY Secondary positrons Best fit propagation parameters

Effect on antiprotons The same example: 1 TeV DM candidate B=400 largely excluded by Pamela! B=40 marginally allowed Antiprotons are strong constraints to exotic contributions!

Conclusions Direct DM detection experiments have exciting results – some tension Positive DM results may nicely be interpreted in terms of relic light neutralinos in effMSSM Indirect DM detection lives as well an intense phase – more standard astrophysics is needed