A new run with Xenoscope, a 2.6 m tall, two-phase xenon tome projection chamber, will start soon. Now the TPC is being reassembled and it looks almost like new ;-)

Muons are wonderful particles. Happy to be part of the new National Centre of Competence in Research "Muoniverse" www.muoniverse.ch, hosted by PSI & UZH. Muoniverse is one of the six funded new centres (www.wbf.admin.ch/en/newnsb/JE...), connecting science, engineering and arts. More details soon!

The first LEGEND-200 results are now published in @physrevlett.bsky.social journals.aps.org/prl/abstract... No evidence for neutrinoless double beta decay, with a lower limit on the 76-Ge half-life of 1.9 x 10^26 y. This corresponds to an upper limit on the Majorana ν mass of m_ββ < 75 - 200 meV

Using the Hubble Space Telescope 🔭, a team of astronomers have discovered a starless, gas-laden dark matter cloud believed to be a relic from the dawn of galaxy formation - the first verified discovery of its kind anywhere in the Universe ☁️. Check it out: https://ow.ly/e0WV50XT9Og #astronomy

It moves! We can watch as the Kepler supernova remnant changes over a quarter of century in X-rays from Chandra. #aas247 chandra.si.edu/photo/2026/k...

This spectacular image of the planetary alignment of Saturn, Mars, Venus, and Jupiter above the Sydney Opera House was taken in the early morning around April 21, 2022, and featured as NASA's Astronomy Picture of the Day on April 26, 2022

Our colleague Katherine Wright, who began as an editor for PRL and went on to explore her passion as a great writer for @physicsmagazine.bsky.social, passed away this fall from cancer, far too young. Here is a tribute to her: physics.aps.org/articles/v18...

If you're in Zurich, join us for today's Physics Colloquium at the @ethz.ch campus: Prof. Teresa Montaruli, from Université de Genève, will talk about "The Future of the Highest Energy Astrophysics with Gamma-Rays and Neutrinos" colloquium.phys.ethz.ch/programme/cu...

Beautiful day in Zurich for the start of the 10 Years of mesoSPIM workshop at the Careum this morning: www.ema.uzh.ch/en/register/... - organised by @mesospim.bsky.social

Study for life

Reading another famous Nobel Lecture, from 1961, for my introductory lecture to electron-nucleus and electron-nucleon scattering this morning (#KT-I) www.nobelprize.org/prizes/physi...

Congratulations to my wonderful colleague John Clarke! And to Berkeley, and to UC. And to everyone who still believes that foundational research is worth investing in

Congratulations to John Clarke, Michel H. Devoret and John M. Martinis! Very good news for quantum sensor based dark matter experiments :)

With XENONnT we reached a very low radon level, equivalent to about 430 222-Rn atoms per tonne of xenon. For the first time, the radon induced background rate is similar to the event rate due to solar neutrinos (via neutrino-electron scattering): link.aps.org/doi/10.1103/...

If you’re in Zurich, support the students’ demo against budget cuts in education - October 1, Helvetiaplatz www.vauz.uzh.ch/de/News/01.1...

CEνNS: an “act of hubris” fifty years ago, now observed by several experiments with neutrinos from stopped pion beams, nuclear reactors and the Sun: cerncourier.com/full-coheren...

Fresh from the underground: the third argon fill at DEAP-3600 is now complete ✅. The detector is filled to full capacity and ready for the next steps! Work continues at @snolabscience.bsky.social #teamwork #darkmatter

You can access the full article here: journals.aps.org/prl/abstract...

Very nice result from a combined analysis of the data from the ANAIS and COSINE experiments: no annual modulation in their NaI(Tl) detectors is observed

Apply for the new PhD school at GGI in Arcetri, “Theory Meets Experiments 2025 - Direct Detection across Dark Matter mass ranges” www.ggi.infn.it/showevent.pl... Deadline is October 5.

WE LONG TO SEE / WHAT CANNOT BE SEEN - this was a fun project with UZH’s Arts x Science Office and the artist Andrea Mettler. First show at Mode Suisse at the Kunsthaus on September 1, next show in Osaka in late September. If I only knew how to breakdance ;-) www.art-science.uzh.ch/de/ausstellu...

Wavefunction Collapse xkcd.com/3134/

💥How can light-sheet help reveal dark matter?💥 Join Prof. Laura Baudis @lbaudis.bsky.social at #mesoSPIM Symposium, Oct 13–15 in Zurich or online, to see how light-sheet fluorescence microscopy 🔬 is used to image nuclear ☢️ recoil tracks to detect elusive particles! Register now: t.uzh.ch/1Ss

Dracula is nowhere to be seen, nor Vlad Țepeș, who never lived here. But beautiful interiors and surroundings

Only 1000 m to go ;-)

True then, and now “Dr. Gaillard’s appointment showed that physicists did not have to be arrogant or aggressive to succeed, said Marjorie Shapiro, who was then a physics graduate student at Berkeley and who in 2004 became the first woman to chair the physics department at Berkeley.”

Happy Birthday, Rosalind Franklin. She captured an X-ray diffraction image of DNA and stated that a helical structure was probable. Watson and Crick then created a detailed model based on her results. They initially received credit for the discovery and were awarded the Nobel Prize after her death.🧪

Happy to see many old friends and colleagues at ICRC in Geneva indico.cern.ch/event/125893...

In recent years, the focus shifted to light DM particles; this was different in the early 90s: "negative results in annihilation searches, in accelerator experiments, and in direct-detection experiments had tended to shift the focus of interest to progressively heavier WIMPs." A. Gould, APJ 1992

When the dream has always to design a subway system but your day job is keeping the Wikipedia page for Desiderius Erasmus Roterodamus - commonly known in English as Erasmus of Rotterdam or simply Erasmus - up to date. en.wikipedia.org/wiki/Erasmus

Back at LNGS

With XENONnT data we looked for spontaneous radiation as predicted by dynamical quantum collapse models. No signal above background was observed, and we set constraints on the free parameters of two benchmark models. With leading contributions by my PhD student Alex Bismark: arxiv.org/abs/2506.05507

After the run

World-leading constraints are placed on dark-matter particles with mass between 100 keV and 1 GeV which could have been boosted to relativistic energies via collisions with cosmic rays go.aps.org/4kK20JR 🧪⚛️ #OpenAccess

Last week my colleagues and I visited the Bedretto underground lab, operated by the @ethz.ch (bedrettolab.ethz.ch/en/home/). For now, umbrellas to protect our small neutron detectors were needed, but in the future we might outfit the deep tunnel (~1500 m overburden) for rare event searches ;)

Hm, ja. Und nein.

Naturally, our XLZD submission is the last in the alphabetical list of inputs to the 2026 European Strategy for Particle Physics. If you're curious about its physics, design, technical challenges, timeline, and funding (all in just 8 pages ;-) have a look at the PDF: indico.cern.ch/event/143985...

Some good news, our paper on the impact of the LNV neutrino self-interactions just got accepted by PRL! You can read a short summary I wrote about it on the N3AS website n3as.berkeley.edu/p/lepton-vio...

If you are in Zurich: join us for today’s Schrödinger colloquium by Bill Bialek from Princeton, on the physics of life (note special day and room): www.physik.uzh.ch/en/seminars/...

Summarise this document into bullet points. Now tell me how to understand bullet points. Translate bullet points into simple pictograms, now describe the pictograms in words of one syllable. Now convert the inchoate noises I make in response to the pictograms into a masters thesis, honours level.

The ERC welcomes the offer of substantial additional budget from @ec.europa.eu for the development of a new ERC funding instrument offering larger, longer-term grants, as announced by President Ursula Von der Leyen at the Sorbonne this morning. 👉 europa.eu/!NTYTTV

It's a privilege to share this honour with @nbuchmann.bsky.social as well as @lbaudis.bsky.social at Uni Zürich!

«Donald Trump besitzt uns» - gutes Interview mit T.C. Boyle im Tagesanzeiger: www.tagesanzeiger.ch/wie-bestsell...

If you like liquid xenon detectors - our article on commissioning Xenoscope, a 2.6 m tall dual-phase TPC demonstrator for XLZD, is now online. Just in time for the next run starting up after Easter ;-) iopscience.iop.org/article/10.1...

If you're in Zurich: Today’s Schrödinger Colloquium will be delivered by Prof. Mark Thomson, Professor at the Cavendish Laboratory, University of Cambridge, and incoming Director-General of CERN. He will speak on the topic: “Particle Physics – Today and Tomorrow”" www.physik.uzh.ch/schroedinger/

Neutrinos may or may not be shrinking, but this is a great new result from the KATRIN experiment: new direct upper limit on the (effective electron) neutrino mass of 0.45 eV (90% CL). This comes from precision measurements of tritium β-decays in a huge spectrometer: www.science.org/doi/10.1126/...

Spherical stupidity

It’s that time of year again! Starting our annual campaign with @ehtelescope.bsky.social and happy to share that our first night has been triggered!! Telescopes across the planet and in space are looking at some supermassive black holes! 🧪🔭