I. F. M. Albuquerque

Energy estimation of cosmic rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy density is determined from the radio pulses at each observer position and is interpolated using a two dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.

Direct detection constraints on superheavy dark matter

The dark matter in the Universe might be composed of superheavy particles (mass greater, similar 10(10) GeV). These particles can be detected via nuclear recoils produced in elastic scatterings from nuclei. We estimate the observable rate of strongly interacting supermassive particles (simpzillas) in direct dark matter search experiments. The simpzilla energy loss in Earth and in the experimental shields is taken into account. The most natural scenarios for simpzillas are ruled out based on recent EDELWEISS and CDMS results. The dark matter can be composed of superheavy particles only if these interact weakly with normal matter or if their mass is above 10(15) GeV.

Constraints on self interacting dark matter from IceCube results

If dark matter particles self-interact, their capture by astrophysical objects should be enhanced. As a consequence, the rate by which they annihilate at the center of the object will increase. If their self scattering is strong, it can be observed indirectly through an enhancement of the flux of their annihilation products. Here we investigate the effect of self-interaction on the neutrino flux produced by annihilating dark matter in the center of the Sun. We consider annihilation into two channels: W+W− (or τ+τ− for a dark matter mass below the W mass) and b. We estimate the event rate in the IceCube detector, using its 79-string configuration, and compare our prediction to their experimental results, hence probing dark matter self interacting models.

SEARCH FOR LIGHT SUPERSYMMETRIC BARYONS

We have searched for the production and decay of light supersymmetric baryons produced in 800 GeV/c proton copper interactions in a charged hyperon beam experiment. We observe no evidence for the decays R{sup +}(uud{tilde g}){r_arrow} S{sup 0}(uds{tilde g}){pi}{sup +} and X{sup -}(ssd{tilde g}){r_arrow} S{sup 0}(uds{tilde g}){pi}{sup -} in the parent mass and lifetime ranges of 1700{endash}2500 MeV/c{sup 2} and 50{endash}500ps. Production upper limits for R{sup +} at x{sub F}=0.47, P{sub t}=1.4GeV/c{sup 2} and X{sup -} at x{sub F}=0.48, P{sub t}=0.65GeV/c{sup 2} of less than 10{sup -3} of all charged secondary particles produced are obtained for all but the highest masses and shortest lifetimes predicted. {copyright} {ital 1997} {ital The American Physical Society}

Probing Velocity Dependent Self-Interacting Dark Matter with Neutrino Telescopes

Self-interacting dark matter models constitute an attractive solution to problems in structure formation on small scales. A simple realization of these models considers the dark force mediated by a light particle which can couple to the Standard Model through mixings with the photon or the

Constraints on Enhanced Dark Matter Annihilation from IceCube Results

Z

Effects of the energy error distribution of fluorescence telescopes on the UHECR energy spectrum

boson. Within this scenario we investigate the sensitivity of the IceCube-DeepCore and PINGU neutrino telescopes to the associated muon neutrino flux produced by dark matter annihilations in the Sun. Despite the models simplicity, several effects naturally appear: momentum suppressed capture by nuclei, velocity dependent dark matter self-capture, Sommerfeld enhanced annihilation, as well as the enhancement on the neutrino flux due to mediator late decays. Taking all these effects into account, we find that most of the model relevant parameter space can be tested by the three years of data already collected by the IceCube-DeepCore. We show that indirect detection through neutrinos can compete with the strong existing limits from direct detection experiments, specially in the case of isospin violation.

Indirect probes of supersymmetry breaking in the JEM-EUSO observatory

Excesses on positron and electron fluxes\char22{}measured by ATIC and the PAMELA and Fermi-LAT telescopes\char22{}can be explained by dark matter annihilation in the Galaxy, however, it requires large boosts on the dark matter annihilation rate. There are many possible enhancement mechanisms such as the Sommerfeld effect or the existence of dark matter clumps in our halo. If enhancements on the dark matter annihilation cross section are taking place, the dark matter annihilation in the core of the Earth will be enhanced. Here we use recent results from the IceCube 40-string configuration to probe generic enhancement scenarios. We present results as a function of the dark matter-proton interaction cross section,

WG III Report on TeV Particle Astrophysics

{\ensuremath{\sigma}}_{\ensuremath{\chi}p}

New upper limit for the branching ratio of the Omega ---> Xi - gamma radiative decay.

weighted by the branching fraction into neutrinos