News

We are pleased to announce that Dr. Ricardo Peres has been awarded a prestigious and highly competitive Marie Skłodowska-Curie Postdoctoral Fellowship.

Ricardo has started the 2 years fellowship at Imperial College London in the group of Prof. Henrique Araújo last June. His project, IRIS-XLZD, will focus on R&D for the next-generation xenon observatory, XLZD. Building on his work at the University of Zurich, Ricardo will investigate the use of SiPMs to improve the optical readout instrumentation of the liquid xenon skin and explore solutions to ensure the supernova-readiness of the future detector . The project will also involve close collaboration with the group at UZH, including joint R&D using the Xenoscope facility.

We hosted the yearly XENONnT workshop on high energy electronic recoil analysis channels. Our group is highly involved in the coordination and in several analyses, working on double weak decays of Xe124, Xe136 and Xe134.

During the five-days workshop, we focused on developing common tools such as simulations and template builders for the background, and statistical inference. We also discussed the next steps and goals of the group for the upcoming year.

After the intense working days we also found some time to enjoy Zurich and to try fondue!

The first results from the QROCODILE (Quantum Resolution-Optimized Cryogenic Observatory for Dark matter Incident at Low Energy) experiment are published in Phys. Rev. Lett. 135, 081002. In the paper, also featured in Physics, we use superconducting nanowire single-photon detector (SNSPD) to search for dark matter (DM) candidates with masses as low as 30 keV. We set new world-leading constraints for DM-electron scattering, DM-nucleon scattering and electronic absorption of dark photon.

You can find more info on the experiment and the collaboration on our website.

QROCODILE through the words of our collaborator in Phys.org 

The XENONnT collaboration has hit a groundbreaking milestone in their relentless efforts of mitigating their experimental backgrounds in their search for dark matter. A major hurdle is the background from radon and its decay products, which are omnipresent in trace amounts in nearly all materials and have long been a dominant source of background noise in the hunt for rare events. In a recent paper published in Physical Review X which got also featured in Physics, the team details their innovative use of a high-flow cryogenic distillation facility allowing to separate their xenon from the radon, resutling in a four fold reduction in the radon background. For the first time, they have achieved radon-induced background activities which are comparable to those from solar neutrinos. This remarkable advancement is set to improve their rare-event searches and enhance the sensitivity of future liquid xenon detectors.

We are delighted to congratulate our summer student Elena Muñoz Rivas for receiving the Best Presentation Award at the CHIPP Summer Student Program 2025 (S3P3).

During her two-month research stay with our group, Elena conducted electric field simulations for an upgrade of our local R&D liquid xenon time projection chamber Xurich. Her work focused on optimizing the detector design to achieve high drift-field homogeneity over an extended field range — a key step in preparing for upcoming precision measurements of the liquid xenon response to particle interactions, providing refined input for signal models used in the Dark Matter searches carried out by collaborations involving UZH, including XENONnT, LZ, and XLZD.

The award is shared with Simone Pasquini, who also contributed to R&D efforts on liquid xenon detectors in the UZH group led by Björn Penning. Congratulations to both Elena and Simone for their outstanding achievements!

We congratulate our group member Dr. Marta Babicz for being awarded the prestigious UZH Postdoc Grant for early career researchers.

As part of the LEGEND collaboration, Marta will use this fellowship to pursue the search for signatures of neutrinoless double electron capture in 36-Ar with data from the LEGEND-200 experiment. This research contributes to the broader effort of probing the fundamental nature of neutrinos and testing lepton number violation.