Measuring the neutron electric charge with high-visibility grating interferometry
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BORIS DOI
Abstract
The neutron is a fundamental particle bound in atomic nuclei and is traditionally considered electrically neutral. However, any minuscule deviation from zero charge could provide insights into new physics beyond the Standard Model of particle physics. Precise neutron property measurements are essential for advancing fundamental physics and improving the performance of neutron-based experimental techniques. This dissertation presents a comprehensive study on the design, development and characterization of the QNeutron apparatus, a cold neutron time-of-flight Talbot-Lau interferometer. To improve the current best upper limit on the neutron electric charge, this instrument must be optimized for high-precision measurements, focusing particularly on neutron beam deflections induced by a sample or an externally applied electric field. The apparatus can operate in two distinct regimes: ballistic and diffraction. Both have been meticulously characterized in order to find the most sensitive setup with the given experimental conditions.
This work involves simulations and extensive experimental characterizations at leading neutron research facilities, including the Paul Scherrer Institute and the Institut Laue-Langevin. These efforts culminated in a first-of-its-kind measurement of the neutron electric charge, achieving a statistical sensitivity of
σ(Qn) = 1.06 × 10−19e
in about 84 hours of data taking, where e is the elementary charge. Although not yet competitive with the current best limit, this result demonstrates the potential of the QNeutron apparatus for high-precision measurements.
This work involves simulations and extensive experimental characterizations at leading neutron research facilities, including the Paul Scherrer Institute and the Institut Laue-Langevin. These efforts culminated in a first-of-its-kind measurement of the neutron electric charge, achieving a statistical sensitivity of
σ(Qn) = 1.06 × 10−19e
in about 84 hours of data taking, where e is the elementary charge. Although not yet competitive with the current best limit, this result demonstrates the potential of the QNeutron apparatus for high-precision measurements.
Date of Publication
2025
Year of graduation
2024
Theses Type
dissertation
Subject(s)
Language(s)
en
Author(s)
Persoz, Marc |
Faculty/Graduate School
Access(Rights)
open.access
Primary OA Publication
true