Neutron Electric Dipole Moment at Fixed Topology
نویسنده
چکیده
We describe the finite volume effects of CP-odd quantities, such as the neutron electric dipole moment and the anapole moment in the θ-vacuum, under different topological sectors. We evaluate the three-point Green’s functions for the electromagnetic current in a fixed non-trivial topological sector in order to extract these CP-odd observables. We discuss the role of zero modes in the CP-odd Green’s function and show that, in the quenched approximation, there is a power divergence in the quark mass for CP-odd quantities at finite volume.
منابع مشابه
Cern{th/96{18 Implications of the Strange Spin of the Nucleon for the Neutron Electric Dipole Moment in Supersymmetric Theories
Supersymmetric model contributions to the neutron electric dipole moment arise via quark electric dipole moment operators, whose matrix elements are usually calculated using the Naive Quark Model (NQM). However, experiments indicate that the NQM does not describe well the quark contributions q to the nucleon spin, and so may provide misleading estimates of electric dipole operator matrix elemen...
متن کاملSearch for an electric dipole moment of the neutron
The result of a search for the electric dipole moment of the neutron is presented. A short review of past experimental work and theoretical predictions introduces a discussion of the experimental method used in, and the results obtained by, the present work. The weighted mean of three separate groups of data gives (+0.4 + 1.5) X 10 "cm for the neutron's electric dipole moment. We conclude that ...
متن کاملComment on “A proposed method for measuring the electric dipole moment of the neutron using acceleration in an electric field gradient and ultracold neutron interferometry ”
We discuss the proposal of Freedman, Ringo and Dombeck [1] to search for the neutron electric dipole moment using the acceleration of neutrons in an inhomogeneous electric field followed by amplification of the resulting displacement by several methods involving spin independent interactions (gravity) or reflection from curved (spin independent) mirrors.
متن کاملA Lower Bound on the Neutron Electric Dipole Moment in the Weinberg Ansatz for Cp Violation*
We deduce a lower limit on the neutron electric dipole moment in the. Weinberg ansatz for CP violation. The resulting number is comparable to the existing experimental upper limit; this ansatz will therefore be critically tested by the next round of experiments using ultra-cold neutrons.
متن کاملNeutron electric dipole moment in a supersymmetric model with singlet quarks
The neutron electric dipole moment is investigated in a supersymmetric electroweak model admitting SU(2)W singlet and Q = −1/3, say D-type, quarks. Significant CP violating phases appear in the coupling between the singlet D-type quarks and the ordinary d-type quarks. Then, through the d-D mixing effects on the squark mass terms the gluino one-loop diagrams provide naturally the contributions ∼...
متن کامل