L. N. Epele

Quantum Anomaly in Molecular Physics

The interaction of an electron with a polar molecule is shown to be the simplest realization of a quantum anomaly in a physical system. The existence of a critical dipole moment for electron capture and formation of anions, which has been confirmed experimentally and numerically, is derived. This phenomenon is a manifestation of the anomaly associated with quantum symmetry breaking of the classical scale invariance exhibited by the point-dipole interaction. Finally, analysis of symmetry breaking for this system is implemented within two different models: point dipole subject to an anomaly and finite dipole subject to explicit symmetry breaking.

Renormalization of the inverse square potential

The quantum-mechanical D-dimensional inverse square potential is analyzed using field-theoretic renormalization techniques. A solution is presented for both the bound-state and scattering sectors of the theory using cutoff and dimensional regularization. In the renormalized version of the theory, there is a strong-coupling regime where quantum-mechanical breaking of scale symmetry takes place through dimensional transmutation, with the creation of a single bound state and of an energy-dependent s-wave scattering matrix element.

On the propagation of the highest energy cosmic ray nuclei

We study the propagation of ultra-high energy cosmic ray nuclei through the background of cosmic microwave and intergalactic infrared photons, using recent re-estimates for the density of the last ones. We perform a detailed Monte Carlo simulation to follow the disintegration histories of nuclei starting as Fe and reaching the Earth from extragalactic sources. We obtain the maximum energies of the arriving nuclear fragments as well as the mass composition as a function of the distance traveled. Cosmic rays with energies in excess of 2 × 1020 eV cannot originate from Fe nuclei produced in sources beyond 10 Mpc.

Dimensional Transmutation and Dimensional Regularization in Quantum Mechanics I. General Theory

Abstract This is the first in a series of papers addressing the phenomenon of dimensional transmutation in nonrelativistic quantum mechanics within the framework of dimensional regularization. Scale-invariant potentials are identified and their general properties are derived. A strategy for dimensional renormalization of these systems in the strong-coupling regime is presented, and the emergence of an energy scale is shown, both for the bound-state and scattering sectors. Finally, dimensional transmutation is explicitly illustrated for the two-dimensional delta-function potential.

Looking for magnetic monopoles at LHC with diphoton events

Magnetic monopoles have been a subject of interest since Dirac established the relation between the existence of monopoles and charge quantization. The intense experimental search carried thus far has not met with success. The Large Hadron Collider is reaching energies never achieved before allowing the search for exotic particles in the TeV mass range. In a continuing effort to discover these rare particles we propose here other ways to detect them. We study the observability of monopoles and monopolium, a monopole-antimonopole bound state, at the Large Hadron Collider in the γγ channel for monopole masses in the range 500–1000 GeV. We conclude that LHC is an ideal machine to discover monopoles with masses below 1TeV at present running energies and with 5 fb−1 of integrated luminosity.

Dimensional Transmutation and Dimensional Regularization in Quantum Mechanics: II. Rotational Invariance

Abstract A thorough analysis is presented of the class of central fields of force that exhibit: (i) dimensional transmutation and (ii) rotational invariance. Using dimensional regularization, the two-dimensional delta-function potential and the D -dimensional inverse square potential are studied. In particular, the following features are analyzed: the existence of a critical coupling, the boundary condition at the origin, the relationship between the bound-state and scattering sectors, and the similarities displayed by both potentials. It is found that, for rotationally symmetric scale-invariant potentials, there is a strong-coupling regime, for which quantum-mechanical breaking of symmetry takes place, with the appearance of a unique bound state as well as of a logarithmic energy dependence of the scattering with respect to the energy.

Cosmic ray photodisintegration and the knee of the spectrum

Abstract We explore in some detail the scenario proposed to explain the observed knee of the cosmic ray (CR) spectrum as due to the effects of photodisintegration of the CR nuclei by interactions with optical and soft UV photons in the source region. We show that the photon column densities needed to explain the experimental data are significantly lower than those obtained in previous estimations which neglected multinucleon emission in the photodisintegration process. We also treat more accurately the photodisintegration thresholds, we discuss the effects of photopion production processes and the neutron escape mechanism, identifying the physical processes responsible for the qualitative features of the results. This scenario would require the CR nuclei to traverse column densities of ∼5×10 27 –2×10 28 eV/cm 2 after being accelerated in order to reproduce the observed knee, and predicts that the CR composition should become lighter above ∼10 16 eV.

Hadronic interactions models beyond collider energies

Studies of the influence of different hadronic models on extensive air showers at ultra-high energies are presented. The hadronic models considered are those implemented in the well-known QGSJET and SIBYLL event generators. The different approaches used in both codes to model the underlying physics is analyzed using computer simulations performed with the program AIRES. The most relevant observables for both single collisions and air showers are studied for primary energies ranging from

Spontaneous CP violation in an SU(3)L⊗U(1)Y electroweak model

10^{14}

Monopolium: The Key to monopoles

eV up to