Hybrid ring design in the storage-ring proton electric dipole moment experiment

S Hacıömeroğlu,Y K Semertzidis

doi:10.1103/physrevaccelbeams.22.034001

S Hacıömeroğlu, Y K Semertzidis

Open Access

https://doi.org/10.1103/physrevaccelbeams.22.034001

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Abstract

A new, hybrid design is proposed to eliminate the main systematic errors in the frozen spin, storage ring measurement of the proton electric dipole moment. In this design, electric bending plates steer the particles, and magnetic focusing replaces electric. The magnetic focusing should permit simultaneous clock-wise and counter-clock-wise storage to cancel systematic errors related to the out-of-plane dipole electric field. Errors related to the quadrupole electric fields can be eliminated by successive runs of magnetic focusing with different strengths.

Highlights

CP-violation is a necessary condition of the observed baryon-antibaryon asymmetry in our universe [1]
Even though the EDM of charged particles has been probed in storage rings [23,24], one way to improve the sensitivity to the EDM of charged particles is the frozen spin method [25,26,27,28,29,30,31], where the spin is kept along the momentum vector and the radial electric field is acting on the particle EDM for the duration of the storage time
We have suggested a hybrid storage ring EDM method, where the focusing is solely done by alternating focusing magnetic fields, while the horizontal bending is accomplished by vertical electro-static plates

Summary

INTRODUCTION

CP-violation is a necessary condition of the observed baryon-antibaryon asymmetry in our universe [1]. To solve this apparent discrepancy, for an otherwise very successful theory, Peccei and Quinn came up with a new symmetry [13], the breakdown of which requires the existence of axions [14,15,16,17,18,19] With or without this axion field, the contribution of the θQCD-term can be anywhere below the current experimental limits. The storage ring EDM method is proposed to reach below 10−29 e · cm, targeting 10−30 e · cm with an upgrade This sensitivity goal is possible due to the high intensity polarized beams available, the long spin coherence time, and the high analyzing power for magic momentum protons.

EXPERIMENTAL METHOD USING A HYBRID RING LATTICE

REDM þ

CW and CCW beam storage

CONCLUSIONS