String theory is a physical model that represents elementary particles by vibrating strings with the aim of unifying the four forces of nature (gravitational, electromagnetic, strong nuclear, and weak nuclear). As a closed string (i.e a loop) moves through space, it may split into two (corresponding to fission), which may later recombine into one (corresponding to fusion). The path traced by a ...

The covariant regularization of the contributions of fundamental particles to the vacuum energy density is implemented in the Pauli-Villars, dimensional regularization, and Feynman regulator frameworks. Rules of correspondence between dimensional regularization and cutoff calculations are discussed. Invoking the scale invariance of free field theories in the massless limit, as well as consisten...

We propose a possible answer to one of the most exciting open questions in physics and cosmology, that is the question why we seem to experience four-dimensional space-time with three ordinary and one time dimensions. Making assumptions (such as particles being in first approximation massless) about the equations of motion, we argue for restrictions on the number of space and time dimensions. (...

The “Standard Model” of elementary particle physics encompasses the progress that has been made in the past half-century in understanding the weak, electromagnetic, and strong interactions. The name was apparently bestowed by my Ph. D. thesis advisor, Sam B. Treiman, whose dedication to particle physics kindled the light for so many of his students during those times of experimental and theoret...

Elementary particle scatterings and decays in presence of a background magnetic field are very common in physics, specially after the observation that the core of the neutron stars can sustain a magnetic field of the order of 10 G. The important point about these calculations is that they are done in a background of a gauge field and as a result the calculations are prone to gauge arbitrariness...

In a space of d Grassmann coordinates two types of generators of Lorentz transformations can be defined, one of spinorial and the other of vectorial character. Both kinds of operators appear as linear operators in Grassmann space, definig the fundamental and the adjoint representations of the group SO(1, d−1), respectively. The eigenvalues of commuting operators belonging to the subgroup (SO(1,...

Uniting the usually distinct areas of particle physics and quantum field theory, gravity and general relativity, this expansive and comprehensive textbook of fundamental and theoretical physics describes the quest to consolidate the basic building blocks of nature, by journeying through contemporary discoveries in the field, and analyzing elementary particles and their interactions. Designed fo...

In 1954, Yang and Mills founded the non-Abel gauge field theory [1 ]. Since then, the gauge field theory has developed greatly, and has been widely applied to elementary particle theory. Now, we believe that, four kinds of fundamental interactions in nature are all gauge interactions and can be described by gauge field theories. It is generally believed that the principle of local gauge invaria...

Sargent plot, summarizes part of one of the pioneers experiments on nuclear beta decay. Here it is proposed to be used as a motivation, to teach undergraduate students some basic features of the weak interactions. This is done by considering only elementary aspects of special relativity and quantum theories. 1 – Introduction It has been elapsed a time interval of eighty years, since B. W. Sarge...

A central problem in the physics of elementary particles concerns the establishment of their quantum numbers. Recent developments in the theoretical classification of particles states have added impetus to this ac­ tivity as a means of making meaningful confrontation between theoretical proposals and experiment. In this review we confine our attention to the in­ ternal quantum numbers of spin a...