Current status of neutron electric dipole moment experiments

Abstract

New precise measurements of the neutron electric dipole moment (nEDM) are strongly motivated by the tight constraints they will place on new sources of CP violation. A number of experiments are commencing in the next few years that aim to reduce the experimental uncertainty on the nEDM by more than an order of magnitude. The experiments pursue a variety of complementary techniques. The TUCAN (TRIUMF Ultra-Cold Advanced Neutron) EDM experiment is one such experiment which combines a spallation-driven superthermal He-II source of ultracold neutrons with a room-temperature nEDM spectrometer.

Electroweak baryogenesis in aligned two Higgs doublet models

“…As shown in figures 4 and 5, by this improvement, most of the regions in the figures can be tested. The upper limit on the nEDM is also expected to be improved by one order of magnitude at future experiments [159]. As mentioned in section 6, in the regions for the successful electroweak baryogenesis in figures 4 and 5, the maximal value of the nEDM is one order smaller than the current upper limit.…”

Electroweak baryogenesis in aligned two Higgs doublet models

“…4 and 5, by this improvement, most of the regions in the figures can be tested. The upper limit on the nEDM is also expected to be improved by one order of magnitude at future experiments [145]. As mentioned in Sec.…”

One-loop matching for quark dipole operators in a gradient-flow scheme

“…One therefore needs to determine individual contributions to the nucleon EDM and to CP-odd pion-nucleon and nucleonnucleon couplings, which determine nuclear EDM and Schiff moments, at hadronic energy scales. Experimental bounds on the neutron EDM are expected to improve by an order of magnitude with the next generation of experiments [20]. Current determinations of the relevant hadronic matrix elements are primarily based on model estimates from QCD sum rules [21][22][23][24][25][26] or from chiral perturbation theory [27][28][29][30][31], which have large, O(50% − 100%), uncertainties and preclude rigorous reduction of systematic uncertainties in theoretical predictions.…”