On the gravitational structure of elementary particles

Gravitational Bags are spherically symmetric solutions of higher dimensional Kaluza-Klein (K-K) theories, where the compact dimensions become very large near the center of the geometry, although they are small elsewhere. K-K excitations become therefore very light when located near the center of this geometry and this appears to affect drastically the naive tower of masses spectrum of K-K theories. In the context of string theories, string excitations can be enclosed by Gravitational Bags, making them not only lighter, but also localized as observed by somebody who does not probe the central regions. Strings however can still have divergent sizes, as quantum mechanics seems to demand, since the extra dimensions blow up at the center of the geometry.This essay received the second award from the Gravity Research Foundation for the year 1989-Ed.     

On the masses of elementary particles

We make an attempt to describe the spectrum of masses of elementary particles, as it comes out empirically in six distinct scales. We argue for some rather well defined mass scales, like the electron mass; we elaborate on the assumption that there is a minimum mass associated to any electric charge. Another natural mass scale is Λ = Λ _QCD coming arbitrarily at quantizing a classically conformal SU(3) _c theory. Indeed, some scales of masses will cover also masses of composite particles or mass differences. We extend some plausible arguments for other scales, as binding or self-energy effects of the microscopic forces, plus some speculative uses, here and there, of gravitation. We also consider briefly exotics like supersymmetry and extra dimensions in relation to the mass scale problem, including some mathematical arguments (e.g. triality), which might throw light on the three-generation problem. We also address briefly the issues of dark matter and dark energy.     

An electromagnetic inertial mass theory applied to elementary particles

A definition of inertial mass is advanced which views this mass property as being due to intrinsic periodic electromagnetic processes characterized by an amplitudeR and an angular frequencyω. The existence of a stableE/M composite mass unit, called a hylon, is then postulated composed of two or more of these primitive processes. Selected space-time coherence relations are then imposed onω andR through ad hoc quantizations based on notions borrowed from historical physical theories. Elementary particles are then investigated to test the efficacy of the mass definition and coherence relations. It is found that by equating the postulated hylon mass with the experimental pion masses, a mass spectrum emerges which has a close correspondence with many of the more stable particles and resonances. A case is then made for considering these particles as being primarily electromagnetic in nature and exhibiting an underlying space-time structure in terms of the theory advanced.     

On the mass spectrum of elementary particles

A simple theory of the elementary particle mass spectrum is proposed. It originates from the Dirac idea of the free electron motion and from the transformed Klein-Gordon equation. The theory is based on an equation that includes the squared mass operator having an infinite sequence of orthogonal eigenfunctions and a discrete spectrum of eigenvalues. A discrete mass formula is derived. It yields values of mass that are in agreement with present-day empiric data for elementary particles.     

On nonlinear field theories of elementary particles

A nonlinear field equation has been derived from a gauge formalism. It has been shown that a soluble nonlinear equation, the sine-Gordon equation, can be obtained from the general nonlinear equation. The physical interpretation is given.Work supported by the National Research Council of Canada.Talk given at the Third International Workshop On Weak Interactions with Very High Energy Beams, Columbus, Ohio, U.S.A., September 3–13, 1975.     

Hyperfine interactions as clues to the structure of elementary particles

The history of hyperfine interactions in hadron physics is reviewed. The recent treatment of hyperfine splittings in meson spectroscopy by Frank and O'Donnell is generalized and applied to baryons as well as mesons by the use of techniques developed for treating hyperfine interactions in atomic physics. New relations between meson and baryon mass splittings are obtained following from the assumption that mesons and baryons are made of the same quarks and have the same color hyperfine interactions at the quark level, with corrections due to color factors and differences between baryon and meson wave functions. Work supported by the U.S. Department of Energy, Division of High Energy Physics, Contract W-31-109-ENG-38 and by the Minerva Foundation, Munich, Germany. 1985–86 Argonne Fellow on leave from the Wiezmann Institute of Science, Rehovot, Israel.     

On nuclear energy levels and elementary particles

Considering only exchange forces, the binding energies and excited states of nuclei up to ²⁴ Mg are predicted to within charge independence, and there is no reason why the model should not be extended to cover all of the elements. A comparison of theory with experiment shows that the energy of one exchange is 2.56 MeV. Moreover, there is an attractive well of depth 30 MeV, corresponding to the helium nucleus, before exchange forces become operative. A possible explanation of the origin of mesons is also presented.     

On the electromagnetic cloaking of (Nano)particles

We theoretically study the electromagnetic cloaking of small (nano)particles in optical or IRbands by means of multilayered coating simultaneously providing the shielding of cloaked volume and minimizing scattering. Within a quasi-static approximation in sphe rical geometry, we show that two kinds of shielding shells exist with zero and with infinitely large (in the lossless case) values of the dielectric constant. We demonstrate that narrowing of the shielding shell at zero dielectric permittivity leads to the effect of electric field superlocalization when an infinite amount of energy is concentrated inside an infinitesimal volume.     

On the electromagnetic radiation of channeled particles in a curved crystal

A simple model calculation of the channeling of charged particles in a curved crystal is presented. The characteristics of the powerful radiation from relativistic particles associated with the motion in a curved channel are discussed.     

Critical exponents and elementary particles

Particles are shown to exist for a.e. value of the mass in single phase ⁴ lattice and continuum field theories and nearest neighbor Ising models. The particles occur in the form of poles at imaginary (Minkowski) momenta of the Fourier transformed two point function. The new inequalitydm ²/dZ, where =m ₀ ² is a bare mass² andZ is the strength of the particle pole, is basic to our method. This inequality implies inequalities for critical exponents.Supported in part by the National Science Foundation under grant PHY 76-17191Supported in part by the National Science Foundation under grant MPS 75-21212     

On the electromagnetic emission from charged test particles in a five-dimensional spacetime

We study the motion of charged particles radially falling in a class of static and electromagnetic-free, five-dimensional Kaluza–Klein backgrounds. Particle dynamics in such spacetimes is explored by an approach à la Papapetrou. The electromagnetic radiation emitted by these particles is studied, outlining the new features emerging in the spectra for the five-dimensional case. A comparison with the dynamics in the four-dimensional counterpart, i.e. the Schwarzschild background, is performed.     

Classical elementary particles in general relativity

Elementary particles, regarded as the constituents of quarks and leptons, are described classically in the framework of the general relativity theory. There are neutral particles and particles having charges±1/3e. They are taken to be spherically symmetric and to have mass density, pressure, and (if charged) charge density. They are characterized by an equation of state P=– suggested by earlier work on cosmology. The neutral particle has a very simple structure. In the case of the charged particle there is one outstanding model described by a simple analytic solution of the field equations.     

On the coherent inelastic processes in collisions of elementary particles with nuclei at ultrarelativistic energies

The coherent inelastic processes of the type a → b, which may take place in the interaction of hadrons and γ quanta with nuclei at very high energies (the nucleus remains the same), are theoretically investigated. Analytical formulas for the effective cross-section σ_coh(a→b) are obtained.     

Cosmological implications of the tetron model of elementary particles

Based on a possible solution to the tetron spin problem, a modification of the standard Big Bang scenario is suggested, where the advent of a space-time manifold is connected to the appearance of tetronic bound states. The metric tensor is constructed from tetron constituents and the reason for cosmic inflation is elucidated. Furthermore, there are natural dark matter candidates in the tetron model. The ratio of ordinary to dark matter in the universe is calculated to be 1:5.     

Detection of elementary charges on colloidal particles

We have succeeded in determining the charge of individual colloidal particles with resolution higher than the elementary charge. The number of elementary charges on a particle is obtained from the analysis of optical tracking data of weakly charged silica spheres in an electric field in a nonpolar medium. The analysis also yields an accurate value of the particle size. Measurement of the charge as a function of time reveals events in which the particle loses or gains an elementary charge due to ionization or recombination processes at the surface.     

A possible estimate of the elementary length in electromagnetic interactions

The difference of 0·2 MHz between the theoretical and experimental values of the Lamb shift of the hydrogen terms 2s _1/2 and 2p _1/2 is used to estimate the elementary length λ in an electromagnetic interaction. The calculated difference of the hydrogen terms in the Bopp-Podolsky potential field\(\varphi (r) = \frac{e}{{4\pi r}}(1 - e - ^{r/\lambda } )\) is compared with the given difference Δ?0·2 MHz. From this we then get for the elementary length λ?0·1× 10^-13 cm. The distribution of the electric charge in the proton\(\varrho (r) = \frac{e}{{4\pi \lambda ^2 }}\frac{{e - ^{r/\lambda } }}{{^ - r}}\) leads to the Bopp-Podolsky potential if the Coulomb interaction is assumed to be valid in the whole space.     

In search of elementary spin 0 particles

The Standard Model of strong and electroweak interactions uses point-like spin 1/2 particles as the building bricks of matter and point-like spin 1 particles as the force carriers. One of the most important questions to be answered by the present and future particle physics experiments is whether the elementary spin 0 particles exist, and if they do, what are their interactions with the spin 1/2 and spin 1 particles. Spin 0 particles have been searched extensively over the last decades. Several initial claims of their discoveries were finally disproved in the final experimental scrutiny process. The recent observation of the excess of events at the LHC in the final states involving a pair of vector bosons, or photons, is commonly interpreted as the discovery of the first elementary scalar particle, the Higgs boson. In this paper we recall examples of claims and subsequent disillusions in precedent searches spin 0 particles. We address the question if the LHC Higgs discovery can already be taken for granted, or, as it turned out important in the past, whether it requires a further experimental scrutiny before the existence of the first ever found elementary scalar particle is proven beyond any doubt. An example of the Double Drell–Yan process for which such a scrutiny is indispensable is discussed in some detail.