Recent design studies for the novel momentum spectrometer NoMoS

D Moser,M Valentan,T Soldner,W Khalid,G Konrad,J Zmeskal,R Jiglau

doi:10.1088/1742-6596/1643/1/012005

D Moser, M Valentan + Show 5 more

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https://doi.org/10.1088/1742-6596/1643/1/012005

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Abstract

NoMoS is a novel momentum spectrometer with which we aim to measure the spectra of the charged neutron beta decay products with high precision. The shape of the proton and electron spectra can inter alia be used for the determination of the electron-antineutrino correlation coefficient a and the Fierz interference term b, respectively. These observables can in turn be used to test the Standard Model of Particle Physics and to search for extensions thereof. NoMoS utilizes the R × B drift effect present in curved magnetic fields, which disperses charged particles according to their momentum. In this paper, we report on selected recent investigations that were conducted with regard to the magnet design and the detection system.

Highlights

NoMoS, the Neutron decay products Momentum Spectrometer, is designed to measure momentum spectra primarily of the charged decay products in free neutron beta decay [1, 2]
NoMoS is a novel momentum spectrometer with which we aim to measure the spectra of the charged neutron beta decay products with high precision
The shape of the proton and electron spectra can inter alia be used for the determination of the electron-antineutrino correlation coefficient a and the Fierz interference term b, respectively. These observables can in turn be used to test the Standard Model of Particle Physics and to search for extensions thereof

Summary

Introduction

NoMoS, the Neutron decay products Momentum Spectrometer, is designed to measure momentum spectra primarily of the charged decay products in free neutron beta decay [1, 2]. Measuring the spectra of the electrons and protons opens the door to several interesting observables, such as the electron-antineutrino correlation coefficient a or the Fierz interference term b. They affect the shape of the proton and electron spectrum, respectively. Numerous experiments have been built or are under construction to measure these observables with high precision: conducted measurements of a have achieved an accuracy of ∆a/a = 2.6% [8] (PDG) whereas b was determined with an accuracy of ∆b = 0.09 [9]. Nab plans to measure the Fierz interference term with an ultimate precision of ∆b < 10−3 [13]. The ultimate goal of NoMoS is ∆a/a < 0.3% and ∆b < 10−3

Objectives

Conclusion