Paul H. Cox

On the electric dipole moment of the neutron

Abstract A nonvanishing contribution to the neutron electric dipole moment, from the interaction of the photon with two-quark subsystems, is calculated. In the Kobayashi—Maskawa model the resulting value of the moment is estimated as O(10−32 e cm; however, strong interaction corrections (gluonic radiative corrections) could give a quark moment contribution which may be numerically larger (possibly 10−30±1e cm).

CP violation in gauge theories and the electric dipole moment of the neutron

Abstract A nonvanishing contribution to the neutron electric dipole moment in CP-violating gauge theories of the weak interactions, arising from interaction of the photon with two-quark subsystems of the three-bound-quark neutron system, is calculated. In the Kobayashi-Maskawa model the resulting value of the moment is estimated as O (10 −32 ) e cm; however, strong interaction corrections (gluonic radiative corrections) give quark moment contributions which may be numerically larger (possibly 10 −30±1 e cm). Either case clearly distinguishes gauge-sector CP violation from Higgs-sector CP violation which typically gives a neutron moment of order 10 −24 e cm.

Extended unified field theories: An SU(7) model

Abstract Seeking a theory which unifies strong and electroweak interactions, we propose an SU(7) model which provides an explanation to the flavor question while avoiding the introduction of a t quark. This model is found to be consistent with low energy phenomenology, including the reported decays B → J/Ψ Kπ, and to contain intermediate mass scales such that new physical processes may occur at levels subject to experimental verification.

Stability of Einstein-Maxwell-Kalb-Ramond Wormholes

This paper investigates a particular type of wormhole. The wormhole solutions studied are obtained by sewing together two static, spherically symmetric, charged black-hole metrics at their horizons. The charged wormholes are in a background Kalb-Ramond field, which is the source of the necessary tension in the gravitational field. The metric-tensor elements are studied by numerically solving Einsteins equations with stress-energy-tensor elements given by the combination of static electric and Kalb-Ramond fields. For a certain range of electric charge the tension is positive away from the wormhole throat, but the tension is negative near the throat, making it non-traversable. The wormholes are found to be quasi-stable against decay via gravitational instanton tunnelling.

Quark electric dipole moments in the standard model

Abstract It is shown that quark electric dipole moments contributing to the neutron moment, in the standard six-quark SU(2) × U(1) model of weak and electromagnetic interactions, cannot be large enough to be observable in present or projected experiments. For M Top ≲ 1 4 M W , an optimistic upper limit is 10 −31 e · cm; a realistic maximum is 10 −34 e · cm. These limits are comparable to the leading standard model diquark contribution to the neutron moment, and extremely small compared to scalar-exchange CP -violation model estimates (which are comparable to present experimental limits).

Charmed meson production in quark exchange model

Abstract Dynamical calculations of charmed meson production rates (via quark exchange) are presented, replacing previous kinematic predictions. Agreement with recent data on the ratio of production rates for different two-charmed-meson final states is reached, and other features of the calculated rates are also discussed.