Direct determination of the atomic mass difference of Re187 and Os187 for neutrino physics and cosmochronology

TL;DR

This paper reports the first direct measurement of the atomic mass difference between Re-187 and Os-187 using advanced Penning-trap mass spectrometry, resolving previous discrepancies and aiding neutrino mass and cosmochronology studies.

Contribution

It introduces a novel phase-imaging ion-cyclotron-resonance technique for direct mass difference measurement, providing more accurate data for neutrino physics and cosmochronology.

Findings

Measured mass difference: 2492(30stat)(15sys) eV

Results agree with indirect microcalorimetry values

Resolves long-standing measurement discrepancies

Abstract

For the first time a direct determination of the atomic mass difference of 187Re and 187Os has been performed with the Penning-trap mass spectrometer SHIPTRAP applying the novel phase-imaging ion-cyclotron-resonance technique. The obtained value of 2492(30stat)(15sys) eV is in excellent agreement with the Q values determined indirectly with microcalorimetry and thus resolves a long-standing discrepancy with older proportional counter measurements. This is essential for the determination of the neutrino mass from the beta-decay of 187Re as planned in future microcalorimetric measurements. In addition, an accurate mass difference of 187Re and 187Os is also important for the assessment of 187Re for cosmochronology.