Neutron EDM Experiment Research Articles

Polarized Cold-neutron Reflectometry at JRR-3/MINE2 for the Development of Ultracold-neutron Spin Analyzers for a Neutron EDM Experiment at TRIUMF

Polarized Cold-neutron Reflectometry at JRR-3/MINE2 for the Development of Ultracold-neutron Spin Analyzers for a Neutron EDM Experiment at TRIUMF

A flavorful factoring of the strong CP problem

Motivated by the intimate connection between the strong CP problem and the flavor structure of the Standard Model, we present a flavor model that revives and extends the classic mu = 0 solution to the strong CP problem. QCD is embedded into a SU(3)1 × SU(3)2 × SU(3)3 gauge group, with each generation of quarks charged under the respective SU(3). The non-zero value of the up-quark Yukawa coupling (along with the strange quark and bottom-quark Yukawas) is generated by contributions from small instantons at a new scale M ≫ ΛQCD. The Higgsing of SU(3)3 → SU(3)c allows dimension-5 operators that generate the Standard Model flavor structure and can be completed in a simple renormalizable theory. The smallness of the third generation mixing angles can naturally emerge in this picture, and is connected to the smallness of threshold corrections to overline{theta} . Remarkably, overline{theta} is essentially fixed by the measured quark masses and mixings, and is estimated to be close to the current experimental bound and well within reach of the next generation of neutron and proton EDM experiments.

The Contribution of Novel CP Violating Operators to the nEDM using Lattice QCD

In this talk, we motivate the calculation of the matrix elements of novel CP violating operators, the quark EDM and the quark chromo EDM operators, within the nucleon state using lattice QCD. These matrix elements, combined with the bound on the neutron EDM, would provide stringent constraints on beyond the standard model physics, especially as the next generation of neutron EDM experiments reduce the current bound. We then present our lattice strategy for the calculation of these matrix elements, in particular we describe the use of the Schr\"odinger source method to reduce the calculation of the 4-point to 3-point functions needed to evaluate the quark chromo EDM contribution. We end with a status report on the quality of the signal obtained in the lattice calculations of the connected contributions to the quark chromo EDM operator and the pseudoscalar operator it mixes with under renormalization.

Plans for a Neutron EDM Experiment at SNS

The electric dipole moment of the neutron, leptons, and atoms provide a unique window to Physics Beyond the Standard Model. We are currently developing a new neutron EDM experiment (the nEDM Experiment) [4]. This experiment, which will be run at the 8.9 Å Neutron Line at the Fundamental Neutron Physics Beamline (FNPB) at the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory, will search for the neutron EDM with a sensitivity two orders of magnitude better than the present limit. In this paper, the motivation for the experiment, the experimental method, and the present status of the experiment are discussed.

An estimate of the uncertainty due to counting statistics in a novel type of neutron EDM experiment

A novel type of EDM experiment using ultracold neutrons produced in a superthermal source, coupled with the dressed neutron technique has been proposed. Here an estimate is made of the uncertainty in the electric dipole moment of neutron that would arise from neutron counting statistics an experiment.