# The 27th International Conference on Atomic Physics

17-22 July 2022
Royal Conservatory of Music, Toronto
America/Toronto timezone

## High-Precision Mass Measurements of Light Atomic Nuclei: The Helium-4 Atomic Mass

18 Jul 2022, 17:00
1h 30m
Hart House (Hart House)

### Hart House

#### Hart House

7 Hart House Cir, Toronto, ON M5S 3H3
Poster presentation Precision measurement and tests of fundamental physics

### Description

Atomic masses with high precision can be determined by Penning-trap mass spectrometry. The LIONTRAP experiment is one such high-precision mass spectrometer that can achieve relative mass uncertainties of the order of 10$^{−12}$ and is dedicated to light ions. Measurements on light ions are challenging due to the relatively large ratio of kinetic energies compared to the low rest mass.

The results at LIONTRAP include the atomic mass measurements of the proton [1], the deuteron and the HD$^+$ molecular ion [2]. The deuteron mass was measured to a relative precision of 8.5 ppt [2]. Our results show an excellent agreement with values that were extracted from laser spectroscopy of HD$^+$ [3]. This comparison is currently limited by the precision of the electron’s mass in atomic mass units (amu), derived from a measurement of the bound electron ${\it g}$-factor in $^{12}$C$^{5+}$ [4]. $^4$He is a prime candidate for a future improvement, as it is far less sensitive to higher-order terms of quantum electrodynamics (QED) and to the charge radius of the nucleus. Currently, we have measured the atomic mass of $^4$He to support such a determination of the electron mass in amu.

Furthermore, an ultra-precise measurement of the mass difference of $^3$He and $^3$T will provide an important crosscheck of the determination of the electron anti-neutrino mass with the KATRIN experiment [5]. Moreover, $^3$He to $^{12}$C mass ratio could further clarify the so-called ‘puzzle of the light masses’, which is an inconsistency in the values of light masses from different world-leading experiments [2]. In this contribution, the present status of the experiment will be discussed.

[1] F. Heiße $\textit{et al}$., Phys. Rev. A $\textbf{100}$, (2019).
[2] S. Rau $\textit{et al}$., Nature $\textbf{585}$, pp. 43-47 (2020).
[3] I. V. Kortunov $\textit{et al}$., Nature Physics, $\textbf{17}$, pp. 569-573 (2021).
[4] S. Sturm $\textit{et al}$., Nature $\textbf{506}$, pp. 467-470 (2014).
[5] KATRIN Collaboration, Nature Physics, $\textbf{18}$, pp. 160-166 (2022).

Presenter name Sangeetha Sasidharan I am planning on in-person attendance

### Primary authors

Mrs Sangeetha Sasidharan (Max Planck Institute for Nuclear Physics, Heidelberg, Germany / GSI Helmholtzzentrum, Darmstadt, Germany ) Ms Olesia Bezrodnova (Max Planck Institute for Nuclear Physics, Heidelberg, Germany) Dr Sascha Rau (Max Planck Institute for Nuclear Physics, Heidelberg, Germany) Dr Wolfgang Quint (GSI Helmholtzzentrum, Darmstadt, Germany) Dr Sven Sturm (Max Planck Institute for Nuclear Physics, Heidelberg, Germany) Prof. Klaus Blaum (Max Planck Institute for Nuclear Physics, Heidelberg, Germany)

### Presentation Materials

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