International Journal of Modern Physics A

Early work on the compositeness of hadrons is reviewed, with emphasis on Quarks and Confinement.

The exciting findings and activities in particle physics in the 50's and 60's will be discussed from an experimentalist's viewpoint. Particular emphasis will be placed on the description of several crucial discoveries (including the omega minus) and on the remarkable insight, guidance, and major contributions of Murray Gell-Mann to the understanding of the symmetry of hadrons which led to the development of the standard model of the strong interactions.

I give a brief review of advances in the strong interaction theory. This talk was delivered at the Conference in honor of Murray Gell-Mann's 80th birthday, 24–26 February 2010, Singapore.

We propose a supersymmetric extra U(1) model, which can generate small neutrino masses and necessary μ terms, simultaneously. Fields including quarks and leptons are embedded in three 27's of E₆ in a different way among generations. The model has an extra U(1) gauge symmetry at TeV regions, which has discriminating features from other models studied previously. Since a neutrino mass matrix induced in the model has a constrained texture with limited parameters, it can give a prediction. If we impose neutrino oscillation data to fix those parameters, a value of sin θ₁₃ can be determined. We also discuss several phenomenological features which are discriminated from the ones of the MSSM.

Simple new relations are presented between the one-loop effective Lagrangians of spinor and scalar particles in constant curvature background fields, both electromagnetic and gravitational. These relations go beyond the well-known cases for self-dual background fields.

We obtain the bound state energy eigenvalues and the corresponding wave functions of the Dirac particle for the generalized Hulthén potential plus a ring-shaped potential with pseudospin and spin symmetry. The Nikiforov–Uvarov method is used in the calculations. Contribution of the angle-dependent part of the potential to the relativistic energy spectra are investigated. In addition, it is shown that the obtained results coincide with those available in the literature.

A gravitational theory involving a vector field χ^μ, which has the properties of a dynamical space–time, is studied. The variation of the action with respect to χ^μ gives the covariant conservation of an energy–momentum tensor . Studying the theory in a background that has Killing vectors and Killing tensors, we find appropriate shift symmetries of the field χ^μ which lead to conservation laws. The energy–momentum that is the source of gravity is different but related to and the covariant conservation of determines in general the vector field χ^μ. When is chosen to be proportional to the metric, the theory coincides with the Two Measures Theory, which has been studied before in relation to the Cosmological Constant Problem. When the matter model consists of point particles, or strings, the form of , solutions for χ^μ are found. In a locally inertial frame, the vector field corresponds to the locally flat coordinates. For the case of a string gas cosmology, we find that the Milne universe can be a solution, where the gas of strings does not curve the space–time since although , , as a model for the early universe, this solution is also free of the horizon problem. There may also be an application to the "time problem" of quantum cosmology.

It is shown that the Einstein gravitational equations and the canonical equations, which follow from the Dirac–Schwinger Hamiltonian, in the Faddeev variables coincide. To prove this, first, the Einstein equations are rewritten in canonical variables and then the time derivative of the generalized momenta of the gravitational field in Faddeev form are calculated using canonical Poisson brackets. The results coincide.

In this paper, we calculate the one-loop quantum cosmological corrections to the kink energy in the closed Friedmann–Robertson–Walker universe in which the fluctuation potential V″ has a shape invariance property. We use the generalized zeta-function regularization method to implement our setup for describing quantum kink-like states. It is conjectured that the corrections lead to the renormalized gravitational constant.

We present the derivation of Hawking radiation by using the tunneling mechanism in a rotating and charged black hole background. We show that the four-dimensional Kerr–Newman metric, which has a spherically nonsymmetric geometry, becomes an effectively two-dimensional spherically symmetric metric by using the technique of the dimensional reduction near the horizon. We can thus readily apply the tunneling mechanism to the nonspherical Kerr and Kerr–Newman metric.