High efficiency positron accumulation for high-precision magnetic moment experiments.

S Fogwell Hoogerheide,J C Dorr,E Novitski,G Gabrielse

doi:10.1063/1.4919413

S Fogwell Hoogerheide, J C Dorr + Show 2 more

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https://doi.org/10.1063/1.4919413

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Abstract

Positrons are accumulated within a Penning trap designed to make more precise measurements of the positron and electron magnetic moments. The retractable radioactive source used is weak enough to require no license for handling radioactive material, and the radiation dosage 1 m from the source gives an exposure several times smaller than the average radiation dose on the earth's surface. The 100 mK trap is mechanically aligned with the 4.2 K superconducting solenoid that produces a 6 T magnetic trapping field with a direct mechanical coupling.

Highlights

A great triumph of the standard model of particle physics1 is the remarkable, part-per-trillion agreement between the most precise measurement of a property of an elementary particle and the standard model’s most precise prediction
Positrons are accumulated within a Penning trap designed to make more precise measurements of the positron and electron magnetic moments
The electron magnetic moment is measured to 3 parts in 1013 using one electron in a 100 mK Penning trap

Summary

Introduction

A great triumph of the standard model of particle physics is the remarkable, part-per-trillion agreement between the most precise measurement of a property of an elementary particle and the standard model’s most precise prediction. The electron magnetic moment is measured to 3 parts in 1013 using one electron in a 100 mK Penning trap.. The positron magnetic moment could be measured just as precisely with a positron suspended in the same trap apparatus. Comparing the positron and electron moments would test the CPT theorem (charge conjugation, parity, and time reversal) with leptons about 15 times more precisely than the best previous comparison of a lepton and antilepton.. Comparing the positron and electron moments would test the CPT theorem (charge conjugation, parity, and time reversal) with leptons about 15 times more precisely than the best previous comparison of a lepton and antilepton.10 This fundamental theorem of the standard model predicts that the positron moment should be opposite in sign but equal in magnitude to the electron moment Comparing the positron and electron moments would test the CPT theorem (charge conjugation, parity, and time reversal) with leptons about 15 times more precisely than the best previous comparison of a lepton and antilepton. This fundamental theorem of the standard model predicts that the positron moment should be opposite in sign but equal in magnitude to the electron moment

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