相关论文: Requiem for an FCHAMP?
Extension of particle symmetry implies new conserved charges and the lightest particles, possessing such charges, should be stable. Created in early Universe, stable charged heavy leptons and quarks can exist and, hidden in elusive atoms…
Stable charged heavy leptons and quarks can exist and hide in elusive atoms, bound by Coulomb attraction and playing the role of dark matter. However, in the expanding Universe it is not possible to recombine all the charged particles into…
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…
The observed Standard Model is consistent with the existence of vector-like species with electric charge a multiple of $e/6$. The discovery of a fractionally charged particle would provide nonperturbative information about Standard Model…
We investigate the evolution of the bound state of negatively charged massive particles (CHAMPs) with light elements and discuss its cosmological consequences and the constraint. By numerically solving the Boltzmann equation, we study the…
We continue our study of fractionally charged particles (FCPs) -- particles carrying electric charge a multiple of $e/6$. Discovering an FCP would inform us about both Standard Model physics (what the true gauge group and the one-form…
We examine the possibility that dark matter consists of charged massive particles (CHAMPs) in view of the cosmic microwave background (CMB) anisotropies. The evolution of cosmological perturbations of CHAMP with other components is followed…
The nonbaryonic dark matter of the Universe can consist of new stable charged leptons and quarks, if they are hidden in elusive "dark atoms" of composite dark matter. Such possibility can be compatible with the severe constraints on…
We investigate anomalous strong lens systems, particularly the effects of weak lensing by structures in the line of sight, in models with long-lived electrically charged massive particles (CHAMPs). In such models, matter density…
The Big Bang nucleosynthesis (BBN) in the presence of charged massive particles (CHAMPs) is studied in detail. All currently known effects due to the existence of bound states between CHAMPs and nuclei, including possible late-time…
The nonbaryonic dark matter of the Universe is assumed to consist of new stable particles. Stable particle candidates for cosmological dark matter are usually considered as neutral and weakly interacting. However stable charged leptons and…
We propose simple freeze-in models where the observed dark matter abundance is explained via the decay of an electrically charged and/or coloured parent particle into Feebly Interacting Massive Particles (FIMP). The parent particle is…
Recent cosmological observations, such as the measurement of the primordial 4He abundance, CMB, and large scale structure, give preference to the existence of extra radiation component, Delta N_nu > 0. The extra radiation may be accounted…
The nonbaryonic dark matter of the Universe is assumed to consist of new stable forms of matter. Their stability reflects symmetry of micro world and particle candidates for cosmological dark matter are the lightest particles that bear new…
Many scenarios of physics beyond the standard model predict new light, weakly coupled degrees of freedom, populated in the early universe and remaining as cosmic relics today. Due to their high abundances, these relics can significantly…
We improve earlier Galactic bounds that can be placed on the fraction of dark matter in charged elemental particles (CHAMPs). These constraints are of interest for CHAMPs whose mass is too large for them to have seen through their…
We report on a search for charged massive long-lived particles (CMLLPs), based on 5.2 fb$^{-1}$ of data collected with the D0 detector at the Fermilab Tevatron $p\bar{p}$ collider. CMLLPs are predicted in many theories of physics beyond the…
Within the framework of canonical type-I seesaw, a feebly interacting massive particle (FIMP) $\chi$ is introduced as a dark matter candidate. The leptogenesis mechanism and dark matter relic density share a common origin via decays of…
We consider a scenario where the dark sector includes two Feebly Interacting Massive Particles (FIMPs), with couplings to the Standard Model particles that allow their production in the Early Universe via thermal freeze-in. These couplings…
We describe our ongoing work on, and future plans for, searches in bulk matter for fractional charge elementary particles and very massive elementary particles. Our primary interest is in searching for such particles that may have been…