Abstract:
A new model for the substructure of quarks, leptons and weak gauge bosons is discussed. It is based on three fundamental and absolutely stable spin-1/2 preons. Its preon flavour SU(3) symmetry leads to a prediction of nine quarks, nine leptons and nine heavy vector bosons. One of the quarks has charge $-4e/3$, and is speculated to be the top quark (whose charge has not been measured). The flavour symmetry leads to three conserved lepton numbers in all known weak processes, except for some neutrinos, which might either oscillate or decay. There is also a (Cabibbo) mixing of the $d$ and $s$ quarks due to an internal preon-antipreon annihilation channel. An identical channel exists inside the composite $Z^0$, leading to a relation between the Cabibbo and Weinberg mixing angles.

Abstract:
A metric of Birkhoffian form is employed to model a hybrid astrophysical compact object consisting of a preon gas core, a mantle of electrically charged hot quark-gluon plasma, and an outer envelope of charged hadronic matter which is matched to an exterior Reissner-Nordstr\"om vacuum. The piecewise-continuous metric and the pressure and density functions consist of polynomials that are everywhere well-behaved. Boundary conditions at each interface yield estimates for physical parameters applicable to each layer, and to the star as a whole.

Abstract:
Inner and empirically consistent model of elementary particles, including two matter structural levels beyond the quark one is built. Excitations spectra, masses and interactions are analysed using the phenomenological notion of non-pertubative vacuum condensate. Essential low-energy predictions of developed concepts are classified. Effective gauge U(1)xU(1)xSU(2)-theory of quark-lepton excitations behavior based on the performed analysis of preon-subpreon phenomenology is consistently built. The ability of its expansion with fermions and scalar leptoquark coupling is also considered. Shown that the coupling constants generation hierarchy is the same as generation hierarchy of quark masses. Using the built theory cross-sections of d-quark-positron scattering processes with both charged and neutral currents are calculated. The obtained resonance peak is proposed to be a possible explanation of deviating from Standard Model predictions discovered in DESY in the beginning of 1997 year.

Abstract:
The Higgs mechanism is the favourite cure for the main problem with electroweak unification, namely how to reconcile a gauge theory with the need for massive gauge bosons. This problem does not exist in preon models for quark and lepton substructure with composite $Z^0$ and $W$s, which, consequently, also avoid all other theoretical complications and paradoxes with the Higgs mechanism. We present a new, minimal preon model, which explains the family structure, and predicts several new, heavy quarks, leptons and vector bosons. Our preons obey a phenomenological supersymmetry, but without so-called squarks and sleptons, since this SUSY is effective only on the composite scale.

Abstract:
We present a new minimal model for the substructure of all known quarks, leptons and weak gauge bosons, based on only three fundamental and stable spin-1/2 preons. As a consequence, we predict three new quarks, three new leptons, and six new vector bosons. One of the new quarks has charge $-4e/3$. The model explains the apparent conservation of three lepton numbers, as well as the so-called Cabibbo-mixing of the $d$ and $s$ quarks, and predicts electromagnetic decays or oscillations between the neutrinos $\bar{\nu}_{\mu}$ ($\nu_{\mu}$) and $\nu_e$ ($\bar{\nu}_e$). Other neutrino oscillations, as well as rarer quark mixings and CP violation can come about due to a small quantum-mechanical mixing of two of the preons in the quark and lepton wave functions.

Abstract:
If the preon structure of quarks, leptons and gauge bosons will be proved then in the Universe during a relativistic phase transition the production of nonperturbative preon condensates has occured. Familons are collective excitations of these condensates. It is shown that the dark matter consisting of familon type pseudogoldstone bosons was undergone to two relativistic phase transitions temperatures of which were different. In the result of these phase transitions the structurization of dark matter and therefore the baryon subsystem has taken place. In the Universe two characteristic scales which have printed this phenomenon arise naturally.

Abstract:
Preons are hypothetic constituents of the standard particles. They were initially assumed to have basically similar properties to those of conventional matter. But this is not necessarily the case: the ultimate constituents of matter may feel a different space-time from that of special relativity and exhibit mechanical properties different from those predicted by standard quantum mechanics. They can also play an important cosmological role (inflation, dark matter, dark energy...). It is even not obvious that energy and momentum would have to be conserved in such a scenario. In this series of papers, we review the subject using the superbradyon model as an example, and suggest new ways to explore possible tests of the preon hypothesis.

Abstract:
In the context of the standard model of particle physics, there is a definite upper limit to the density of stable compact stars. However, if a more fundamental level of elementary particles exists, in the form of preons, stability may be re-established beyond this limiting density. We show that a degenerate gas of interacting fermionic preons does allow for stable compact stars, with densities far beyond that in neutron stars and quark stars. In keeping with tradition, we call these objects "preon stars", even though they are small and light compared to white dwarfs and neutron stars. We briefly note the potential importance of preon stars in astrophysics, e.g., as a candidate for cold dark matter and sources of ultra-high energy cosmic rays, and a means for observing them.

Abstract:
In the context of a viable, supersymmetric,preon model,it has been shown by Babu and Pati that the unity of forces can well occur at the level of preons near the Planck scale.This preonic approach to unification is explored further in this note with the inclusion of threshold effects which arise due to spreading of masses near the scale of suppersymmetry ($M_S=1$ TeV) and the metacolor scale (${\Lambda}_M=10^11$ GeV).These effects,which were ignored in the earlier work,are found to have marked consequences on the running and unification of relevant couplings leading to new possibilities for flavor-color as well as metacolor gauge symmetries.In particular, allowing for seemingly reasonable threshold effects,it is found that the metacolor gauge symmetry,$G_M$ is either $SU(6)_M$ or $SU(4)_M$ (rather than $SU(5)_M$) and the corresponding flavor-color gauge symmetry is either $SU(2)_LXU(1)_RXSU(4)_C$ (for $G_M=SU(6)_M$) or even just the standard model symmetry $SU(2)_LXU(1)_YXSU(3)_C$ (for $G_M=SU(6)_M or SU(4)_M$). Prospects of other preonic gauge symmetries are also investigated.

Abstract:
We discuss possible ways to observationally detect the superdense cosmic objects composed of hypothetical sub-constituent fermions beneath the quark/lepton level, recently proposed by us. The characteristic mass and size of such objects depend on the compositeness scale, and their huge density cannot arise within a context of quarks and leptons alone. Their eventual observation would therefore be a direct vindication of physics beyond the standard model of particle physics, possibly far beyond the reach of the Large Hadron Collider (LHC), in a relatively simple and inexpensive manner. If relic objects of this type exist, they can possibly be detected by present and future x-ray observatories, high-frequency gravitational wave detectors, and seismological detectors. To have a realistic detection rate, i.e., to be observable, they must necessarily constitute a significant fraction of cold dark matter.