Neutralino annihilation to mono-energetic gamma rays Haim Goldberg - PowerPoint PPT Presentation

1 Neutralino annihilation to mono-energetic gamma rays Haim Goldberg Northeastern University, Boston May 11, 2010 Pheno-2010 • D-branes, dijet signals at the LHC and all that • Strings, broken R-symmetry, and efficient s-wave annihilation of neutralinos • Copious branching to monoenergetic gamma rays • . . . and prospects for near term discovery L. Anchordoqui, HG, D. Hooper, D. Marfatia, T. Taylor, Phys. Lett. B683 (2010) 321 (arXiv:0912.0517 [hep-ph]) May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

2 TeV scale strings • Large extra spatial dimensions and D-brane constructs allow → low string scale compatible with weak 4-D gravity – in toroidal compactification M 2 Pl ∼ M 2 s ( M s R ) n → Regge recurrences in TeV region • Open strings can terminate on stack of N identical D branes → U ( N ) gauge group for each stack. Matter fields in bifundamental representations May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

3 Quivers U(3) q L u d R R l L Sp(1) U(1) e R h Berenstein, Pinansky, [hep-th/0610104]; Antoniadis, Kiritsis, Tomaras, [hep-ph/0004214] May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

4 Parallel and perpendicular extra dimensions p=3+d -dimensional brane // open string 3-dimensional brane closed string Minkowski 3+1 dimensions d extra dimensions Extra dimension(s) perp. to the brane || Antoniadis [hep-th/0710.4267] May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

5 Model independence on the color brane • Consider scattering on the U(3) brane, involving quarks and gluons • Gluons live only on a single stack of color branes, don’t see other branes • Momentum in all the p − 3 extra parallel dimensions conserved, so 4-point functions gg → gg, q ¯ q → gg, qg → qg do not excite KK or winding modes – only Regge recurrences independent of compactification. • Not so for qq → qq – these live on intersecting branes, and parallel momentum not conserved – KK/winding modes involved. May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

6 Bumps, etc at LHC L. Anchordoqui, HG, D. Lust, S. Nawata, S. Stieberger, T. Taylor, Phys.Rev.Lett.101:241803,2008; Nucl.Phys.B821:181-196,2009. May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

7 Dijets and direct photons May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

8 5 σ discovery reach at LHC May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

9 Randall-Sundrum geometry 5D Warped Spacetime Planck Gauge Field m = M ⋆ s Light Fermion Higgs Heavy Fermion Graviton � (0) M s <µ th 5 Dimension May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

10 5 σ discovery reach at LHC–Randall-Sundrum May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

11 Dark matter detection • Neutralino LSP’s ( χ 0 ’s) are prime candidates for dark matter HG, Phys. Rev. Lett. 50, 1419 (1983) • Annihilation hindered because of p-wave barrier • Direct Detection in CDMS, XENON, etc. excess of γ -rays, e ± , ν ’s • Indirect Detection: from dense astrophysical environments • ID via monoenergetic γ rays from χ 0 χ 0 → γγ, γZ are loop induced in the MSSM, and for the bino are small (BR ∼ 0.1%) L. Bergstrom, P. Ullio, Nucl. Phys. B504, 27(1997); Phys. Rev. D57, 1962 (1998); Z. Bern, P. Gondolo, M. Perelstein, Phys. Lett. B411 86, 1997 May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

12 New string-based s-wave annihilation to gauge bosons • s-wave annihilation demands that the χ 0 ’s have same helicity • Since χ 0 χ 0 is the A term of a chiral superpotential W W , and the two gauge bosons ( ∼ F 2 ) are in the F term of the same or a different W W , there is a violation of R-symmetry by two units | ∆ r | = 2 . • R-charge deficit related to Euler characteristic χ = 2 − 2 g − h of the string world sheet via − 2 χ ≥ | ∆ r | , χ ≤ 0 . • Therefore require χ = − 1 → g = 1 , h = 1 or g = 0 , h = 3 May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

13 The topologies c’ c I. Antoniadis, K. S. Narain, T. R. Taylor, Nucl Phys B729, 235(2005) May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

14 Stacks, boundaries and effective interactions • Effective lagrangian calculable from topology of compactified dimensions if gaugino and gauge boson vertices are attached to two different boundaries. • Additional non-topological contributions if emitted gauge bosons are in same stack as gauginos, and vertices are attached to same boundary F (0 , 3) (Tr W W ) (Tr W W ) | θθ + h.c. � = 3 g 3 s N M − 3 L eff s F (0 , 3) (Tr λλ ) (Tr F F ) + h.c. . � 3 8 g 3 s N M − 3 = s N = 6 = no of stacks traced out in empty boundary. May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

15 Constraint from relic abundance • To generate measured relic density Ω CDM h 2 = 0 . 113 ± 0 . 003 requires annihilation rate � σv � eff = σv | W W + σv | gg + σv | BB ≃ 3 × 10 − 26 cm 3 / s • For each gluon or W pair σv | W i W i = σv | g i g i F (0 , 3) � 2 � � 2 � M χ � 4 � c � s N � 3 g 3 = 4 π M s c M s May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

16 Constraint (cont’d) • To take account of non-topological contributions to χχ → BB define M ( BB ) ζ = M ( W 3 W 3 ) • Relic constraint is � � � 2 � g s � 6 � ρ � 4 � 2 TeV � 2 F (0 , 3) � � 1 + 0 . 083( ζ 2 − 1) ≃ 1 . 2 . 8 0 . 2 0 . 5 M s May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

17 The Smoking Gun • Rewrite cross sections in terms of γ, Z, W ± , g � � 2 , sin 2 θ W + ζ cos 2 θ W σv | γγ = σv | W 3 W 3 � � 2 , cos 2 θ W + ζ sin 2 θ W σv | ZZ = σv | W 3 W 3 σv | γZ = σv | W 3 W 3 2 cos 2 θ W sin 2 θ W (1 − ζ ) 2 , σv | W + W − = 2 σv | W 3 W 3 , σv | gg = 8 σv | W 3 W 3 • For ζ ≃ 1 obtain nearly 10% branching into γγ – a large number of gamma rays with energy ∼ M χ . May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

18 H.E.S.S. and Galactic Center May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

19 Gamma ray flux from annihilation in GC • Typical branching ratio into monoenergetic gamma rays 1-2 orders of magnitude larger than from 1 loop SUSY • � � � Φ γ ( E γ , ψ ) ≃ σv | i dN γ � n 2 χ 0 ( r ) dl ( ψ ) dψ , � 8 π dE γ l . o . s . i May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

20 Spectrum May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

21 Hint? -11 ) 10 -1 s -2 dN/dE (TeV cm -12 10 2004 (H.E.S.S.) 2003 (H.E.S.S.) MSSM KK × -13 - 70% b b , 30% + 10 τ τ 2 E 1 10 Energy (TeV) May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

22 Summary • Within the context of D-brane TeV-scale string compactifications, we constructed a model that generates a supersymmetric R-symmetry violating effective Lagrangian which allows for the s -wave annihilation of neutralinos (once gauginos acquire mass through an unspecified mechanism). • The model allows for a neutralino relic abundance consistent with the measured dark matter density. • The branching fractions to monochromatic gamma rays is orders of magnitude larger than in the MSSM. • A very bright and distinctive gamma-ray line that May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston

23 may lie within the reach of current or next-generation gamma-ray telescopes is predicted. • A flux near the limit presently imposed by the H.E.S.S. data would strongly support a near purely topological origin for the R-symmetry violating effective Lagrangian. May 11, 2010 Haim Goldberg Neutralino annihilation to mono-energetic gamma rays Pheno-2010 Northeastern University, Boston