Antimatter Bounds by Anti-Asteroids annihilations on Planets and Sun

The existence of antimatter stars in the Galaxy as possible signature for inflationary models with non-homogeneous baryo-synthesis may leave the trace by antimatter cosmic rays as well as by their secondaries (anti-planets and anti-meteorites) diffused bodies in our galactic halo. The anti-meteorite flux may leave its explosive gamma signature by colliding on lunar soil as well as on terrestrial, jovian and solar atmospheres. However the propagation in galaxy and the consequent evaporation in galactic matter gas suppress the lightest (m < 10^(-2)g) anti-meteorites. Anisotropic annihilation of larger anti-meteorites within a narrow mass window, maybe rarely deflected, bounced by the galactic gas disk, escaping detection in our solar system. Nevertheless heaviest anti-meteorites (m > 10^(-1)g up to 10^(6)g) are unable to be deflected by the thin galactic gas surface annihilation; they might hit the Sun (or rarely Jupiter) leading to an explosive gamma event and a spectacular track with a bouncing and even a propelling annihilation on cromosphere and photosphere. Their anti-nuclei annihilation in pions and their final hard gammas showering may be observabe as a "solar flare" at a rate nearly comparable to the observed ones. From their absence we may infer bounds on antimatter-matter ratio near or below 10^(-9) limit: already recorded data in BATSE catalog might be applied.Comment: 6 pages, more accurate estimate and minor correction

Primordial heavy elements in composite dark matter models

A widely accepted viewpoint is to consider candidates for cosmological dark matter as neutral and weakly interacting particles, as well as to consider only light elements in the pregalactic chemical composition. It is shown that stable charged leptons and quarks can exist and, hidden in elusive atoms, play the role of dark matter. The inevitable consequence of realistic scenarios with such composite atom-like dark matter is existence of significant or even dominant fraction of "atoms", binding heavy -2 charged particles and He-4 nuclei. Being alpha-particles with shielded electric charge, such atoms catalyse a new path of nuclear transformations in the period of Big Bang Nucleosynthesis, which result in primordial heavy elements. The arguments are given, why such scenario escapes immediate contradiction with observations and challenges search for heavy stable charged particles in cosmic rays and at accelerators.Comment: Prepared for Proceedings of Blois2007 Conferenc

Probes for 4th generation constituents of dark atoms in Higgs boson studies at the LHC

The nonbaryonic dark matter of the Universe can consist of new stable charged species, bound in heavy neutral "atoms" by ordinary Coulomb interaction. Stable $\bar U$ (anti-$U$)quarks of 4th generation, bound in stable colorless ($\bar U \bar U \bar U$) clusters, are captured by the primordial helium, produced in Big Bang Nucleosynthesis, thus forming neutral "atoms" of O-helium (OHe), a specific nuclear interacting dark matter that can provide solution for the puzzles of direct dark matter searches. However, the existence of the 4th generation quarks and leptons should influence the production and decay rates of Higgs boson and is ruled out by the experimental results of the Higgs boson searches at the LHC, if the Higgs boson coupling to 4th generation fermions with is not suppressed. Here we argue that the difference between the three known quark-lepton families and the 4th family can naturally lead to suppression of this coupling, relating the accelerator test for such a composite dark matter scenario to the detailed study of the production and modes of decay of the 125.5 GeV boson, discovered at the LHC.Comment: Prepared for the Special issue "Dark atoms and dark radiation" of Advances in High Energy Physic

Baryomorphosis: Relating the Baryon Asymmetry to the "WIMP Miracle"

We present a generic framework, "baryomorphosis", which modifies the baryon asymmetry to be naturally of the order of a typical thermal relic WIMP density. We consider a simple scalar-based model to show how this is possible. This model introduces a sector in which a large initial baryon asymmetry is injected into particles ("annihilons") phi_B, \bar{phi}_B of mass ~ 100 GeV - 1 TeV. phi_B-\bar{phi}_B annihilations convert the initial phi_B, \bar{phi}_B asymmetry to a final asymmetry with a thermal relic WIMP-like density. This subsequently decays to a conventional baryon asymmetry whose magnitude is naturally related to the density of thermal relic WIMP dark matter. In this way the two coincidences of baryons and dark matter i.e. why their densities are similar to each other and why they are both similar to a WIMP thermal relic density (the "WIMP miracle"), may be understood. The model may be tested by the production of annihilons at colliders.Comment: 7 pages, 2 figures; Modified to address B washout issue. Higgs replaced by inert doublet, no mixing of annihilons. Version to be published in PRD, typos correcte

Puzzles of Dark Matter - More Light on Dark Atoms?

Positive results of dark matter searches in experiments DAMA/NaI and DAMA/LIBRA confronted with results of other groups can imply nontrivial particle physics solutions for cosmological dark matter. Stable particles with charge -2, bound with primordial helium in O-helium "atoms" (OHe), represent a specific nuclear-interacting form of dark matter. Slowed down in the terrestrial matter, OHe is elusive for direct methods of underground Dark matter detection using its nuclear recoil. However, low energy binding of OHe with sodium nuclei can lead to annual variations of energy release from OHe radiative capture in the interval of energy 2-4 keV in DAMA/NaI and DAMA/LIBRA experiments. At nuclear parameters, reproducing DAMA results, the energy release predicted for detectors with chemical content other than NaI differ in the most cases from the one in DAMA detector. Moreover there is no bound systems of OHe with light and heavy nuclei, so that there is no radiative capture of OHe in detectors with xenon or helium content. Due to dipole Coulomb barrier, transitions to more energetic levels of Na+OHe system with much higher energy release are suppressed in the correspondence with the results of DAMA experiments. The proposed explanation inevitably leads to prediction of abundance of anomalous Na, corresponding to the signal, observed by DAMA.Comment: Contribution to Proceedings of XIII Bled Workshop "What Comes beyond the Standard Model?

Remark on the minimal seesaw model and leptogenesis with tri/bi-maximal mixing

We have studied a leptogenesis scenario in the framework of the minimal seesaw model with tri/bi-maximal mixing. Usually, at least one of the elements in the Dirac mass matrix is fixed to be zero, for example, we denote it by $b_2=0$. We have pointed out that the absolute value of the CP asymmetry has several minimums and maximums with non-zero $b_2$. Thus one can expect that more rich phenomena, such as an enhanced leptogenesis, are hidden in the $b_2 \neq 0$ space.Comment: 9 pages, 7 figures, uses RevTex4. To appear in Physcal Review