SUSY Dark Matter Collider – direct – indirect search bridge. Sabine Kraml Laboratoire de Physique Subatomique et de Cosmologie Grenoble, France ● 43. Rencontres de Moriond La Thuile, 1-8 March 2008

Moriond EW S. Kraml: SUSY dark matter WIMP paradigm DM should be stable, electrically neutral, weakly and gravitationally interacting  WIMPs ― weakly interacting massive particles WIMPs are predicted by most theories beyond the Standard Model (BSM) Stable as result of discrete symmetries Thermal relic of the Big Bang Testable at colliders! Neutralino, gravitino, axino, lightest KK state, T-odd little Higgs, etc.,... BSM-DM c.f. talk by M. Tytgat

Moriond EW S. Kraml: SUSY dark matter let‘s go SUSY...

Moriond EW S. Kraml: SUSY dark matter What is SUSY?  Supersymmetry (SUSY) is a symmetry between fermions and bosons.  The SUSY generator Q changes a fermion into a boson & vice versa  Extension of space-time to include anticommuting coordinates x  → (x ,   ) with         This combines the relativistic “external” symmetries (such as Lorentz invariance) with the “internal” symmetries such as weak isospin.  Actually the unique extension of the Poincare algebra * * (the algebra of space-time translations, rotations and boosts)

Moriond EW S. Kraml: SUSY dark matter space-time symmetry (special relativity) Antiparticles space-time supersymmetry Superpartners doubling of the spectrum

Moriond EW S. Kraml: SUSY dark matter The beauties of SUSY  Unique extension of relativistic symmetries  Solution to gauge hierarchy problem  Radiative EW symmetry breaking, light Higgs  Gauge coupling unification  Ingredient of string theories  Very rich collider phenomenology  Cold dark matter candidate ....

Moriond EW S. Kraml: SUSY dark matter SUSY as a local gauge theory includes a spin-2 state, the graviton (!) and its superpartner the gravitino. Minimal Supersymmetric Standard Model (MSSM) gluino 2 charginos  ± 4 neutralinos   If SUSY comes with a new conserved parity, R P, then the lightest SUSY particle (LSP) is stable  DARK MATTER CANDIDATE Gravitino, sneutrino or lightest neutralino

Moriond EW S. Kraml: SUSY dark matter I am concentrating on the neutralino case. For gravitino DM, see talk by F. Steffen tomorrow morning

Moriond EW S. Kraml: SUSY dark matter SUSY searches at the LHC CMS

Moriond EW S. Kraml: SUSY dark matter 0101 Z q q 0202 jet jets, l + l − missing energy Large cross sections  ~100 events/day for M ~ 1 TeV Spectacular signatures  SUSY could be found early on Cascade decays into LSP lead to typical signature: multi-jets / multi-leptons plus large missing energy LHC Every SUSY event → 2 LSPs. Abundant production! LHC as DM factory

Moriond EW S. Kraml: SUSY dark matter Mass measurements: cascade decays E T miss → no peaks → mass reconstruction through kinematic endpoints [ATLAS, G. Polesello] Typical precisions: a few %

Moriond EW S. Kraml: SUSY dark matter Neutralino annihilation:   LSP as thermal relic: relic density computed as thermally avaraged cross section of all annihilation channels →  h 2 ~  v  −1

Moriond EW S. Kraml: SUSY dark matter Consequences <  h 2 < puts strong constraints on the parameter space of any model variant CMSSM: GUT-scale boundary conditions: m 0, m 1/2, A 0, plus tanb, sgn(  )

Moriond EW S. Kraml: SUSY dark matter Consequences <  h 2 < puts strong constraints on the parameter space of any model variant good  h 2 Simple SO(10) SUSY GUTs: dual requirement of Yukawa unification and DM relic density is extremley predictive → Very distinct LHC signatures: ~ GeV gluinos GeV  1 talk by S. Sekmen in YSF2

Moriond EW S. Kraml: SUSY dark matter Consequences <  h 2 < puts strong constraints on the parameter space of any model variant 2. If we can measure the properties of the SUSY particles precisely enough, then we can compute  v of the LSP → „collider prediction“ of  h 2 → compare with cosmological observations Note: this means measuring (or at least putting limits on) masses and couplings of most of the SUSY spectrum to infer

Moriond EW S. Kraml: SUSY dark matter Consequences <  h 2 < puts strong constraints on the parameter space of any model variant 2. If we can measure the properties of the SUSY particles precisely enough, then we can compute  v →  h 2 3. We can also compute the direct and indirect detection rates direct detection: m ,  N  v, local DM density indir. det.: v→0, density profile, propagation model

Moriond EW S. Kraml: SUSY dark matter However, uncertainties in   N calculation are large (~50%) Direct detection: limits and predictions Xenon10 new CDMS result! Predictions of various SUSY models

Moriond EW S. Kraml: SUSY dark matter Indirect searches: high energetic positrons or gamma rays from  annihilation

Moriond EW S. Kraml: SUSY dark matter Indirect detection: EGRET signal? [W. DeBoer, arXiv: ] 50–70 GeV neutralino? EGRET

Moriond EW S. Kraml: SUSY dark matter Higgs? SUSY? 1 GeV ~ 1.3 * K „It is impossible to overestimate the importance of discovering dark matter at the LHC. Such a discovery will imply a revision of the SM, it will strenghten the connection between particle physics, cosmology and astrophysics, and it will enormously enlarge our understanding of the present and past universe.“ G.F. Giudice, Theories for the Fermi Scale (2007)