Related papers: Preon Prophecies by the Standard Model
We show that in generic leptoquark (LQ) extensions of the standard model lepton and baryon numbers are broken at the level of renormalizable operators. In particular, this may cause fast proton decay unless the leptoquarks are heavy enough.…
Some of the motivations for quark and lepton compositeness, and some problems associated with present schemes, are noted. One model is discussed in which quarks and leptons are taken as composites of spin-1/2 fermions $F$ with charges $\pm…
Many reasons why quarks should be considered composite particles are found in the book Preons by D'Souza and Kalman. One reason not found in the book is that all the quarks except for the u quark decay. The electron and the electron…
For many decades after the invention of the quark model in 1964 there was no evidence that hadrons are formed from anything other than the simplest pairings of quarks and antiquarks, mesons being formed of a quark-antiquark pair and baryons…
Nucleons and electrons were once considered elementary particles, a role nowadays taken by quarks and leptons. Here, mainly at the group theoretical level, we examine the unorthodox idea that nucleons and electrons share the same level of…
A model is presented that fits the quark and lepton masses and mixings wherein five dimensionless parameters and a phase account for fifteen dimensionless observables. Among these are the Wolfenstein parameters $\rho$ and $\eta$, the…
The nonrelativistic quark model predicts that the spin and the magnetic moment of proton are not parallel. Based on, the modifications are outlined that sound crucial for the analysis of the data out of scattering off the protons.
\noindent We propose a set of rules for constructing composite leptons and quarks as triply occupied quasiparticles, in the quaternionic quantum mechanics of a pair of Harari-Shupe preons $T$ and $V$. The composites fall into two classes,…
Precise measurements of the lepton properties provide stringent tests of the Standard Model structure and accurate determinations of its parameters. We overview the present status of a few selected topics: lepton universality, QCD tests and…
The standard model of particle physics is marvelously successful. However, it is obviously not a complete or final theory. I shall argue here that the structure of the standard model gives some quite concrete, compelling hints regarding…
The Standard Model of particle physics currently provides our best description of fundamental particles and their interactions. The theory predicts that the different charged leptons, the electron, muon and tau, have identical electroweak…
I briefly describe the recent construction of the first specific string D-brane models yielding just the SM massless fermion spectrum. One of the most remarkable facts predicted by these constructions is that the global symmetries of the SM…
We turn back to the hypothesis that the Pauli principle, acting intrinsically within leptons and quarks, is the origin of their three generations. The adequate formalism is based on the generalized Dirac equations arising (in the…
A preon-based composite model of the fundamental fermions is discussed, in which the fermions are bound states of smaller entities -- primitive charges (preons). The preon is regarded as a dislocation in a dual 3-dimensional manifold -- a…
The present paper is based upon ideas and results obtained in an earlier paper by the author devoted to a new formulation of quantum electrodynamics. The equations derived in that paper depict the structure and properties of the electron as…
This paper is concerned with a way of thinking about the standard model that explains the existence of three fermion families and the value of the fine structure constant. The main idea is that the ultraviolet divergences that we encounter…
In a model in which quarks and leptons are built up from two spin 1/2 preons as fundamental entities, a new class of fermionic bound states (hyperquarks) arises. It turns out that these hyperquarks are necessary to fulfill the 't Hooft…
The application of fermion-boson symmetry to the standard model leads to the following: first, there are three generations of scalar quarks and scalar leptons in addition to the known quarks and leptons, and, secondly, the divergences in…
The known fundamental symmetries and interactions are well described by the Standard Model. Features of this powerful theory, which are described but not deeper explained, are addressed in a variety of speculative models. Experimental tests…
A model-independent ansatz to describe lepton and quark mixing in a unified way is suggested based upon the Cabibbo angle. In our framework neutrinos mix in a "Bi-Large" fashion, while the charged leptons mix as the "down-type" quarks do.…