Dmitry Gorbunov

Testing the correlations between ultrahigh-energy cosmic rays and BL Lac-type objects with HiRes stereoscopic data

Previously suggested correlations of BL Lac-type objects with the arrival directions of the ultrahigh-energy cosmic ray primaries are tested by making use of the HiRes stereoscopic data. The results of the study support the conclusion that BL Lacs may be cosmic ray sources and suggest the presence of a small (a few percent) fraction of neutral primaries at E > 1019 eV.

On the correlation of the highest-energy cosmic rays with nearby extragalactic objects reported by the Pierre Auger Collaboration

Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrated a correlation between the arrival directions of cosmic rays with energy above 6 x 10(19) electron volts and the positions of active galactic nuclei (AGN) lying within approximately 75 megaparsecs. We rejected the hypothesis of an isotropic distribution of these cosmic rays with at least a 99% confidence level from a prescribed a priori test. The correlation we observed is compatible with the hypothesis that the highest-energy particles originate from nearby extragalactic sources whose flux has not been substantially reduced by interaction with the cosmic background radiation. AGN or objects having a similar spatial distribution are possible sources.We argue that the data published by the Pierre Auger Collaboration [1] disfavors, at the 99% confidence level, their hypothesis that most of the highest-energy cosmic rays are protons from nearby astrophysical sources—either active galactic nuclei or other objects with a similar spatial distribution.We argue that the data published by the Pierre Auger Collaboration (arXiv:0711.2256) disfavor at 99% confidence level their hypothesis that most of the highest-energy cosmic rays are protons from nearby astrophysical sources, either Active Galactic Nuclei or other objects with a similar spatial distribution.

Distinguishing between R 2 -inflation and Higgs-inflation

Abstract We present three features which can be used to distinguish the R 2 -inflation Higgs-inflation from with ongoing, upcoming and planned experiments, assuming no new physics (apart form sterile neutrinos) up to inflationary scale. (i) Slightly different tilt of the scalar perturbation spectrum n s and ratio r of scalar-to-tensor perturbation amplitudes. (ii) Gravity waves produced within R 2 -model by collapsing, merging and evaporating scalaron clumps formed in the post-inflationary Universe. (iii) Different ranges of the possible Standard Model Higgs boson masses, where the electroweak vacuum remains stable while the Universe evolves after inflation. Specifically, in the R 2 -model Higgs boson can be as light as 116 GeV. These effects mainly rely on the lower reheating temperature in the R 2 -inflation.

More about the sgoldstino interpretation of HyperCP events

We further discuss possible sgoldstino interpretation of the observation, reported by the HyperCP collaboration, of three Σ+ → pμ+μ− decay events with the dimuon invariant mass 214.3 MeV within the detector resolution. With a sgoldstino mass equal to 214.3 MeV, this interpretation can be verified at existing and future B and ϕ factories. We find that the most natural values of the branching ratios of two-body B and D meson decays to sgoldstino P and vector meson V are about 10−6−10−7. The branching ratios of ϕ meson decay ϕ → Pγ are estimated to be in the range 1.8 × 10−13−1.6 × 10−7, depending on the hierarchy of supersymmetry-breaking soft terms. Similar branching ratios for ρ and ω mesons are in the range 10−14−3.4 × 10−7.

Constraints on ultra-high energy neutrinos from optically thick astrophysical accelerators

Abstract The Z-burst mechanism invoked to explain ultra-high energy cosmic rays is severely constrained by measurements of the cosmic gamma-ray background by EGRET. We discuss the case of optically thick sources and show that jets and hot spots of active galaxies cannot provide the optical depth required to suppress the photon flux. Other extragalactic accelerators (AGN cores and sites of gamma ray bursts), if they are optically thick, could be tested by future measurements of the secondary neutrino flux.

Lhc prospects in searches for neutral scalars in pp → γγ + jet

At hadron colliders the

Non-minimal split supersymmetry

gammagamma+jet

Estimation of the signal of correlation between cosmic rays and BL Lacertae objects in future data

channel provides larger signal-to-background ratio in comparison with inclusive

Offset of the dark matter cusp and the interpretation of the 130 GeV line as a dark matter signal

gammagamma

Human milk antibodies with polysaccharide kinase activity

channel in hunting for scalars uncharged under the SM gauge group. At NLO in QCD perturbation theory we evaluate selfconsistently the signal significance for the SM Higgs boson production in