Seminario de Daniel Unger (Kirchhoff Institute for Physics, Heidelberg University)

“QUARTET: High-Resolution X-ray Spectroscopy of Light Muonic Atoms” 
Daniel Unger 
(Kirchhoff Institute for Physics, Heidelberg University)

 The low-lying energy levels of muonic atoms are highly sensitive to nuclear structure because of the strong overlap of the muon wavefunction with the nucleus.
In particular, the energy of the muonic 2p–1s transition allows a determination of the nuclear charge radius, a fundamental parameter for the validation of nuclear
models. The QUARTET collaboration aims to improve the precision of nuclear charge radii for light nuclei from lithium to neon by more than an order of magnitude.

In this talk, I will present the development of MMC-based detectors for high resolution X-ray spectroscopy of light muonic atoms within QUARTET. I will review the
first two measurements at the πE1 beamline at PSI: a proof-of-principle run in 2023 and a dedicated data run in 2024 with lithium, beryllium, and boron targets.
A preliminary analysis of the data indicates that the accuracy of the nuclear charge radii of these elements can be improved and demonstrates the feasibility of QUARTET
for achieving significantly higher precision in light nuclei. Finally, I will outline the recent 2025 data run and discuss the future prospects of QUARTET. 

Fecha: lunes, 2 de febrero de 2026
Hora:   12:10 horas
Lugar: Seminario de Física Teórica