Related papers: How many quarks and leptons ?
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…
We present an $S_3$-invariant extension of the SM which is able to account for the mixing both in the quark and the lepton sector. We focus here on the quark sector and present different realizations of the model, according to how many…
The weak bosons, leptons and quarks are considered as composite particles. The interaction of the constituents is a confining gauge interaction. The standard electroweak model is a low energy approximation. The mixing of the neutral weak…
Non-trivial patterns of quark and lepton masses and mixings can arise without there being any underlying flavor symmetry that distinguishes among the three families. Two realistic examples are given.
We assume that strong and electroweak interactions become strong at very high energies. With this assumption, we compute the low-energy gauge coupling constants $\alpha_i (m_Z)$ as a function of the cutoff scale, taking the supersymmetric…
Physics from beyond the Standard Model, such as leptoquarks, can induce four fermion operators involving a quark, an anti-quark, a lepton and an anti-lepton. We update the (flavour dependent) constraints on the coefficients of such…
A quark and lepton mass matrix model with family symmetries U(3)$\times$O(3) is investigated on the basis of the so-called yukawaon model. In the present model, quarks and leptons are assigned to $(\ell, e^c, u^c) \sim ({\bf 3}, {\bf 3},…
I review some selected aspects of the phenomenology of multiquark states discovered in high energy experiments. They have four valence quarks (called tetraquarks) and two of them are found to have five valence quarks (called pentaquarks),…
The origin of the fermion generations is discussed. A strong interactions spin $I_{S}$ is introduced which unifies the quarks and leptons as two multiplets of this spin. The electroweak vector bosons and gluons emerge as the fused states of…
As the most recently discovered and heaviest quark, the top presents us with theoretical challenges. How are we to understand its properties within the larger effort to explain the origins of electroweak and flavor symmetry breaking ? This…
In an effort to understand nuclei in terms of quarks we develop an effective theory to low-energy quantum chromodynamics in which a single quark contained in a nucleus is driven by a mean field due to other constituents of the nucleus. We…
If fourth family condensates are responsible for electroweak symmetry breaking then they may also break approximate global symmetries. Among the resulting pseudo-Goldstone bosons are those that can have diquark quantum numbers. We describe…
We propose a left-right model of quarks and leptons based on the gauge group $SU(3)_C \times SU(2)_L \times SU(2)_R \times U(1)_{B-L}$, where the scalar sector consists of only two doublets: (1,2,1,1) and (1,1,2,1). As a result, any fermion…
The tracelike probability is expressed by the leptons and quarks Hamiltonians.
The mass spectra of the excited heavy baryons consisting of two light (u,d,s) and one heavy (c,b) quarks are calculated in the heavy-quark--light-diquark approximation within the constituent quark model. The light quarks, forming the…
We consider finite groups of small order for family symmetry. It is found that the binary dihedral group Q_6, along with the assumption that the Higgs sector is of type II, predicts mass matrix of a nearest neighbor interaction type for…
In recent papers a microscopic model for the SM Higgs mechanism has been proposed, and an idea how to determine the 24 quark and lepton masses of all 3 generations has emerged in that framework. This idea is worked out in detail here by…
In this paper we present the state of the art about the quarks: group SU(3), Lie algebra, the electric charge and mass. The quarks masses are generated in the same way as the lepton masses. It is constructed a term in the Lagrangian that…
Quarks, leptons and heavy vector bosons are suggested to be composed of stable spin-1/2 preons, existing in three flavours, combined according to simple rules. Straightforward consequences of an SU(3) preon-flavour symmetry are the…
The top quark is the heaviest known elementary particle, and it is often seen as a window to search for new physics processes in particle physics. A large program to study the top-quark properties has been performed both at the Tevatron and…