Keegan Stoner Columbia High School

dark matter

Obeying Inverse Square Law Outer stars orbit too fast what we should seewhat we actually see

dark matter  Galaxies and clusters rotate faster than they should.  Requires more matter to be present.  How do we know it’s not a problem with gravity?  Dark matter in the Bullet Cluster kept moving past the visible matter, making a new type of matter much more probable.

 Satellite-based  Reports an excess of electron/positron signal at GeV  No excess of proton/antiproton.  Leptophilic dark matter is a good candidate for this gap. PAMELA Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics

supersymmetry  All standard model particles have superpartners.  Superpartners related to particles by spin difference of ½.  Mass at TeV scale (very massive).

 Superpositions of the photino, zino, and higgsino.  Mass = 100 GeV – 1TeV.  Very difficult to directly detect.  Can detect annihilation products neutralinos

Detection of annihilation products, rather than actual particle.  Gamma rays  Positrons  Muons  Neutrinos indirect detection

Review of Literature  “Prospects for detecting Dark Matter with Neutrino Telescopes in Light of recent results from Direct Detection Experiments” Francis Halzen and Dan Hooper Modeled the flux of various products form annihilations in the Sun. Used the capture and annihilation rates to estimate number of WIMPs. “New Gamma-Ray Contributions to Supersymmetric Dark Matter Annihilation” Torsten Bringmann, Lars Bergstrom, and Joakim Edsjo Predicted flux of gamma rays detected by GLAST, taking into account many minor factors affecting spectrum of photons from annihilations, including the region in which the annihilation is occurring relative to the entire halo.

Review of Literature  “Limits on a muon flux from neutralino annihilations in the sun with the IceCube 22-string detector” IceCube Researchers Discussed models for neutralino annihilations in the Sun, to produce products detectable by IceCube. Explained how IceCube works and what it’s sensitive to. Explained spectra of various models (W and b decay).

neutralino annihilation pair production Fermion Antifermion

leptophilic dark matter ? New SUSY State e v μ Neutrino Electron Muon m < m p

 Detects neutrinos coming through the Earth.  Muons and neutrinos interact with ice.  Create hadronic shower. icecube Neutrino Detector Use model to predict spectrum of neutrino or muon energies.

Online dark matter computation software DarkSUSY

Parameters:  MSSM 7+  Relic density calculation  Halo model  Standard Model masses  photon  neutrinos  bosons DarkSUSY

 Use a theoretical model of the neutralino  Predict what will happen when they annihilate using DarkSUSY  Predict flux of neutrinos from Center  Integrate over the line-of sight to IceCube  Use IceCube data to see if the data fits model methods

 Eve and Lyle Stoner  Dr. Dan Hooper  Ms. Gleason  Mr. Ross acknowledgements

 Francis Halzen and Dan Hooper. “Prospects for Detecting Dark Matter with neutrino Telescopes in Light of recent results from Direct Detection experiments.” Fermilab  J. Silk, K. Olive and M. Srednicki, Phys. Rev. Lett. 55, 257 (1985); J. S. Hagelin, K. W. Ng, K. A. Olive, Phys. Lett. B 180, 375 (1986); L. Bergstrom, J. Edsjo and P. Gondolo, Phys. Rev. D 58, (1998); V. D. Barger, F. Halzen, D. Hooper and C. Kao, Phys. Rev. D 65, (2002); J. L. Feng, K. T. Matchev and F. Wilczek, Phys. Rev. D 63, (2001). references

 J. Silk and M. Srednicki, Phys. Rev. Lett. 53, 624 (1984); T. Bringmann and P. Salati, Phys. Rev. D 75, (2007) [arXiv:astro-ph/ ].  Torsten Bringmann, Lars Bergstrom, Joakim Edsjo ”New Gamma-Ray contributions to Supersummetric Dark Matter Annihilation” Journal of High Energy Physics 801,  S. Profumo and A. Provenza, JCAP 0612, 019 (2006) [arXiv:hep-ph/ ]. references