Fermion Emission Research Articles

Interaction of fermions with black holes.

Bekenstein and Meisels used statistical thermodynamic arguments to obtain the probability distribution of fermions emitted by a black hole when a fermion is incident. In contrast with Bekenstein and Meisels, we model the black hole as a perfect blackbody surrounded by a mirror. Our probability distribution for emitted fermions agrees with the probability distribution of Bekenstein and Meisels, but the interpretation of how fermions interact with the black hole is different from the interpreteation given by Bekenstein and Meisels.

Gauge invariance, charge conservation, and axial anomaly in fermion-monopole interactions.

A gauge-invariant quantum field theory is formulated for a fermion-monopole system with the finite monopole size taken into account. It is shown that gauge invariance near and inside the monopole requires the inclusion of quantum fluctuations associated with the heavy charged bosons. Scattering of massless fermions is then considered, and an elementary exposition of the Rubakov-Callan effect is given by solving simultaneously the Dirac equation, Maxwell equations, and the axial-anomaly equation. Charge-conserving solutions are explicitly given which may or may not observe chirality. The solutions which break chirality require emission of charged fermions via the axial anomaly.

Anomalous production of chiral charge from black holes

The Reissner Nordström solution to Einstein equations coupled to a Yang-Mills field is unstable against the emission of light-charged fermions. We study the flux chirality in this decay process and illustrate the consistency of the result with the prediction of the axial anomaly.

Fermion emission from a Julia-Zee dyon

A relationship is obtained between the S matrix for the charge-exchange scattering of a fermion by a Julia-Zee dyon and the flux of fermions emitted by the dyon when the mass of the fermions is sufficiently small. In the limit of a pointlike dyon, the required S-matrix elements are obtained in closed form and the corresponding fermion flux is computed explicitly.

The group theoretic structure of dual vertices

The dual fermion emission vertex is constructed, in a manner which makes its gauge properties manifest, by giving it a precise interpretation as an intertwining operator between the Fock-space representations of the Virasoro group. To do this the relation between the Fock-space representations and the representations of the group on spaces of functions is studied. It is shown that the crucial object necessary for the construction of the Fock-space representations is a bilinear form preserved by the group. Given this, a representation can be constructed up to a factor by a canonical procedure. A natural extension of this procedure apploed to a sort of intertwining operator yields the fermoin emission vertex in all its detailed structure.

The superoperator formalism of the Neveu-Schwarz-Ramond model

The Neveu-Schwarz-Ramond model is rewritten in terms of a new operator formalism where the old ones are combined into superoperators, i.e. we will use an extra set of variables, anticommuting Grassman variables, besides the usual Koba-Nielsen variables to describe external legs in dual amplitudes. We show that many formulae become more compact and transparent and find an operator formalism closer to a spinning string picture. We also show that the fermion emission vertex appears in a more natural way in a formalism like this.

Gauge conditions in the dual fermion model

Techniques are developed for handling the vertex for fermion emission in Ramond’s model. These are used to show the vertex for ground-state emission successfully converts all the Virasoro fermion gauge operators into meson ones andvice versa. This is more than is guaranteed by duality. Further it is proved that the vertex converts fermionFN gauges into sums ofGm ones. Unfortunately the more important converse result fails to hold.

The missing gauge conditions for the dual fermion emission vertex and their consequences

We find that the dual vertex for emitting a ground state fermion of mass m converts between generalized mesonic G gauges and generalized fermionic F gauges. These generalized gauges consist of infinite linear combinations of F's and G's which are, roughly speaking, square roots of Virasoro gauges and exhibit partial reflection and transmission behaviour at the vertex. One of these Ward identifies allows us to re-express the amplitude for fermion re-emission in the ¢ 2 representation where the limit m = 0 is well defined. If m = 0 and d = 10 certain meson channels are, we show, saturated by physical (ghost free) states.

Induced emission of neutral fermions moving in a plane wave

The induced emission of neutral fermions having an anomalous magnetic moment and moving in an intense electromagnetic wave under the influence of a second, less intense, electromagnetic wave is analyzed. In this situation the particles may acquire a predominant spin orientation.