In a framework for nonperturbative QCD calculation of high energy processes, the amplitudes for photo-and electroproduction of vector mesons are written as integrals of the overlap product of photon and vector meson wave functions, multiplied by the amplitude for the scattering of qq dipole pairs off the proton. For sizes of the overlap functions that are smaller than the typical ranges of the interaction of the dipoles with the proton, the amplitudes factorize in the form of integrals, here called overlap strengths, formed only with the overlap of the wave functions times the square of the dipole separation. The integration is extended over the light front coordinates describing the qq dipoles. With this result, the overlap strengths contain all Q 2 dependence of the observables. We show the importance of this factorization in the description of the experimental data for all S-wave vector mesons.

In a real scalar field model in 1 + 1 dimensions with quartic and sextic self-coupling there appears a classically unstable nontopological soliton which is a bubble in the false vacuum. We show that this vacuum is rendered stable by one-and two-loop quantum corrections with appropriate renormalization conditions. In a parameter range of the model, the bubble is stabilized when quantum corrections to its mass are taken into account with a quadratic approximation of the higher-order terms.

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We study universality in the electroproduction of vector mesons using a unified nonperturbative approach which has already proved to reproduce extremely well the available experimental data. In this framework, after the extraction of factors that are specific of each vector meson, we arrive at a reduced integrated elastic cross section which is universal.Our calculations suggest a finite infrared behavior for the strong coupling constant.

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