After a very brief review of twentieth century elementary particle physics, prospects for the next century are discussed. First and most important are technological limits of opportunities; next, the future experimental program, and finally the status of the theory, in particular its limitations as well as its opportunities. Invited talk given at the International Conference on Fundamental Scie...

The theory of elementary particles permitting to explain their constitution, sizes, bond energy, possible channels of decay, spectrum of weights and other properties is offered.

Gauge symmetries: These are local symmetries that act differently at each space-time point x = (t,x) . They create particularly stringent constraints on the structure of a theory. For example, gauge symmetry automatically determines the interaction between particles by introducing bosons that mediate the interaction. All current models of elementary particles incorporate gauge symmetry. (Detail...

The spin-statistics connection is proved using the methods of elementary quantum mechanics. The effect of exchange and space inversion operators on two-particle states is reviewed. The connection follows directly from successive application of these operations to the wave function for two identical particles in an s-state, evaluated at positions ±x, but at equal time.

The dynamics of relativistic spinning particles in strong external electromagnetic or gravitational fields is discussed. Spin-orbit coupling is shown to affect such relativistic phenomena as time-dilation and perihelion shift. Possible applications include muon decay in a magnetic field and the dynamics of neutron stars in binary systems. ∗Lecture presented at the 4th Hellenic School on Element...

The inertial (due to rotation) and the gravitational fields of the Earth affect the motion of an elementary particle and its spin dynamics. This influence is not negligible and should be taken into account in high-energy physics experiments. Earth’s influence is manifest in perturbations in the particle motion, in an additional precession of the spin, and in a change of the constitutive tensor ...

We present a nonperturbative method for deriving a quasiparticle description of the low-energy excitations in the t−J model for strongly correlated electrons. Using the exact diagonalization technique we evaluated exactly the spectral functions of composite operators, which describe an electron or hole dressed by antiferromagnetic spin fluctuations as expected in the string or spin bag picture....

Engineering quantum particle systems, such as quantum simulators and quantum cellular automata, relies on full coherent control of quantum paths at the single particle level. Here we present an atom interferometer operating with single trapped atoms, where single particle wave packets are controlled through spin-dependent potentials. The interferometer is constructed from a sequence of discrete...

A model for composite elementary Standard Model (SM) particles based upon magnetically bound vorton pairs, briefly introduced here, predicts the existence of a complete family of magnetically charged particles, as well as their neutral isotopic partners (all counterparts to the SM elementary particles), in which the lowest mass (charged) particle would be an electrically neutral stable lepton, ...