Sergio Palomares-Ruiz November 17, 2008 Dark Matter Annihilation/Decay Scenarios Novel Searches for Dark Matter with Neutrino Telescopes Columbus, OH (USA) November 17-19, 2008

Sergio Palomares-Ruiz November 17, 2008 What do we know about Dark Matter? Astrophysicist view: Particle Physicist view:

Sergio Palomares-Ruiz November 17, 2008

Sergio Palomares-Ruiz November 17, 2008 Model-independent bound Neutrinos are the least detectable particles of the SM From the detection point of view the most conservative assumption (the worst case) is that DM annihilates (decays) only into ν’s: Â Â → νν ( Â → νν) This is not an assumption about realistic models It provides a bound on the total annihilation cross section (lifetime) and not on the partial cross section (lifetime) to neutrinos Anything else would produce photons, and hence would lead to a stronger limit J. F. Beacom, N. F. Bell and G. D. Mack, Phys. Rev. Lett. 99:231301, 2007

Sergio Palomares-Ruiz November 17, 2008 Two energy regions: backgrounds Strategy Calculate neutrino flux Compare potential signal with the background E ~ 100 MeV – 100 TeV: atmospheric neutrino flux E ~ 10 MeV – 100 MeV: invisible muons and atmospheric neutrino flux

Sergio Palomares-Ruiz November 17, 2008 Signal from Annihilations Experiment Particle PhysicsAstrophysics

Sergio Palomares-Ruiz November 17, 2008 Field of View Neutrino Spectrum: Flavor democracy Average of the Line of Sight Integration of ½ 2

Sergio Palomares-Ruiz November 17, 2008 Signal from Decays Experiment Particle PhysicsAstrophysics

Sergio Palomares-Ruiz November 17, 2008 Field of View Neutrino Spectrum: Flavor democracy Average of the Line of Sight Integration of ρ

Sergio Palomares-Ruiz November 17, 2008 Annihilations vs Decays 2 DM particles E = m  Proportional to /m  2 Proportional to ½ 2 1 DM particle E = m  /2 Proportional to 1/ ¿  m  Proportional to ½

Sergio Palomares-Ruiz November 17, 2008 DM Density Profile Uncertainties SPR and S. Pascoli, Phys. Rev. D77:025025, 2008 Local rotational velocity Amount of flatness Non-halo components P. Belli et al., Phys.Rev.D 66:043503, 2002 From the allowed range of: Annihilations: Decays: Extreme values for the 3 profiles: J avg = (1.3, 8.1) SPR, Phys. Lett. B665:50, 2008

Sergio Palomares-Ruiz November 17, 2008 Energy resolution: ¢ log E = 0.3 H. Yüksel, S. Horiuchi, J. F. Beacom and S. Ando, Phys. Rev. D76:123506, 2007 Other related limits M. Kachelriess and P. D. Serpico, Phys. Rev. D76:063516, 2007 N. F. Bell, J. B. Dent, T. D. Jacques and T. J. Weiler, Phys. Rev. D78:083540, 2008 J. B. Dent, R. J. Scherrer and T. J. Weiler, arXiv: G. D. Mack, T. D. Jacques, J. F. Beacom, N. F. Bell and H. Yüksel, Phys. Rev. D78:063542, 2008

Sergio Palomares-Ruiz November 17, 2008 Can we do better? Careful treatment of energy resolution and backgrounds: eg. limits on MeV DM We use SK data for E = MeV Detection: ν e + p → e + + n Two main backgrounds: –Invisible muons –Atmospheric neutrinos M. S. Malek, Ph.D thesis M. S. Malek et al., Phys. Rev. Lett. 90:061101, 2003

Sergio Palomares-Ruiz November 17, 2008 Analysis 16 4-MeV bins in the range [18,82] MeV N l = Number of events in bin l A l = fraction of signal events B l = fraction of Michel electrons (positrons) C l = fraction of atmospheric electron (anti)neutrinos

Sergio Palomares-Ruiz November 17, 2008 We perform a similar  2 analysis as that done by SK to limit the flux of DSNB and we set an upper bound on the DM annihilation cross section SPR and S. Pascoli, Phys. Rev. D77:025025, 2008SPR, arXiv: Annihilations:

Sergio Palomares-Ruiz November 17, 2008 LENA: m 3 scintillator after 10 years Reactor BGDSNBAtmospheric BG SPR and S. Pascoli, Phys. Rev. D77:025025, 2008 What if this is actually the case and DM only annihilates into neutrinos? C. Boehm, Y. Farzan, T. Hambye, SPR and S. Pascoli, Phys. Rev. D 77:043516, 2008

Sergio Palomares-Ruiz November 17, 2008 SPR, Phys. Lett. B665:50, 2008 Model-independent bound from CMB observations K. Ichiki, M. Oguri and K. Takahashi, Phys. Rev. Lett. 93:071302, 2004 Using SK data from DSNB search: Detailed analysis of background and energy resolution New model-independent bound from CMB and SN observations Y. Gong and X. Chen, Phys. Rev. D77:103511, 2008 Decays: For γ-line limits: H. Yuksel and M. Kistler, Phys. Rev. D78:023502, 2008

Sergio Palomares-Ruiz November 17, 2008 A few words on PAMELA O. Adriani et al., arXiv: O. Adriani et al., arXiv: Annihilations: need of large boost factors Sub-structure Sommerfeld enhancement Non-thermal production Decays: no need of boost factors -> “short” lifetime M. Cirelli, M. Kadastik, M. Raidal and A. Strumia, arXiv:

Sergio Palomares-Ruiz November 17, 2008 Conclusions Neutrino detectors can test DM properties Searches for neutrinos from DM annihilations/decays in the galactic halo could constitute powerful probes of DM properties Neutrino detectors can set model- independent bounds on the DM annihilation cross section and on the DM lifetime Difficult to distinguish annihilation/decay scenarios: use angular information Future detectors (LENA) might be able to detect a signal from DM annihilations/decay

Sergio Palomares-Ruiz November 17, 2008 When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth Sherlock Holmes The world is full of obvious things which nobody by any chance ever observes Long arm looking for a fingerprint trying to find the mystery clue Bon Scott