Effective Field Theory Program for Conformal Quantum Anomalies

The emergence of conformal states is established for any problem involving a domain of scales where the long-range, SO(2,1) conformally invariant interaction is applicable. Whenever a clear-cut separation of ultraviolet and infrared cutoffs is in place, this renormalization mechanism produces binding in the strong-coupling regime. A realization of this phenomenon, in the form of dipole-bound anions, is discussed.Comment: 15 pages. Expanded, with additional calculational details. To be published in Phys. Rev.

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.Comment: 5 page

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.Comment: 4 page

Electrons weakly bound to molecules by dipolar, quadrupolar or polarization forces

Within the framework of a simple electrostatic model we here discuss the stability of very weakly bound molecular negative ions. In contrast with the case of conventional valence anions, the excess electron is then located in a very diffuse orbital and is mainly bound by electrostatic dipolar, quadrupolar and polarization forces at large distances from the neutral molecular core. By fitting a single repulsion parameter of the model to the available experimental data, it is possible to make quantitative predictions of the excess electron binding energies in these species. Critical values of dipole moment, quadrupole moment or polarizability required for the observation of stable dipole-bound, quadrupole-bound or polarization-bound negative ions are predicted

Weakly Bound Clusters of Biological Interest

International audienc

Dipole bound and valence state coupling in argon-solvated nitromethane anions

International audienc

Formation of negative clusters by electron attachment in the thermal energy range

Different experimental approaches for the production of negatively charged van der Waals clusters are reviewed, with emphasis on crossing beam techniques. Laser excited Rydberg atoms constitute a source of electrons with tunable well-defined energy in the thermal range (5-300 meV). Different mechanisms occuring in the cluster anions are considered: creation, dissociation, electron autodetachment, evaporation, internal energy exchanges and solvation effects in homogenous and inhomogenous molecular clusters