February 2024

Cool tour of the NIF facility at LLNL. Unfortunately now picture taking was allowed.


February 2024

Having a great time at the Project 8 collaboration meeting at Lawrence Livermore National Laboratory with the group.

February 2024

We got the group together for a Pub Quiz, Pizza and drinks. Thanks everyone for the organization.

December 2023

Our paper "A neutron trigger detector for pulsed reactor neutron sources" is now published in NIM A. Congratulations to Julian and the team.


December 2023

Neutrinos celebrating Sebastian's birthday on the Christmas market.

November, 2023

My colleague Michael Wurm and I were interviewed for the podcast series "Exzellent erklärt".
If you want get to know more aboutn some of the neutrino physics we do in Mainz, please click here.

October, 2023

tSPECT has been completely reassembled at PSI. The cryostat has been cooled down and first neutrons have been delivered to the instrument. Exciting commissioning times for all of the team.


August 11, 2023

We're making great progress assembling tSPECT at PSI. Only with such a great team it is possible to get most of the setup mechanically back together and cabled in less than three weeks. Thanks to the local support at PSI from the UCN group and the support services, and the MuSun collaboration for donating their power chain. Looking forward to neutrons in the setup in a couple of weeks.

August 10, 2023

Today the Muon g-2 collaboration announced its most precise measurement of the muon's anomalous magnetic moment based on the data of Run 2+3. We reduced the total uncertainity by more than a factor of two compared to Run 1. The preprint of the paper is available here. The published PRL is available here.

For a summary about the current theory prediction for the anonmalous magnetic moment the Muon G-2 Theory Initiative has posted a summary here. While our new experimental result is more than 5 standard deviations discrepant from the so-called White Paper value from 2020 we have to be patient to see how the theory community will update their predicition given the progress with lattice QCD calculations and the new results from CMD3.

A summary of the experimental principles and the result is provided on this poster:

July 25, 2023

The local team at PSI makes fantastic prgress to reassemble the tSPECT experiment at PSI. Thank you to the team!


July 2023

New results from the Muon g-2 experiment at Fermilab will be unveiled in a scientific seminar on August 10, 2023 at 10:00am US Central Time. The seminar will be livestreamed on the Fermilab YouTube channel. Further information and a link to the webinar can be found here. If your research institution is interested to request a post-release presentation of the new Muon g-2 result, please use this Google form to contact the speaker's committee.


July 20, 2023

The first parts of the tSPECT experiment have been installed in the UCN West 1 experimental area at PSI today. This heroic effort was only possible with our great team of postdocs, graduate students, under graduate students, and technicians. All other parts are in the storage area and will be put back together in the next couple of weeks.

July 2023

Our first limit on a neutrino mass based on the frequencny-based cylotron radiation emission spectroscopy technology will appear in Physical Review Letters.

July 2023

Our neutron lifetime experiment will continue at the UCN source of the Paul Scherrer Institut. The experimental area UCN West 1 is ready to be filled with our measurement equipment in the next couple of weeks.
The source of ultra-cold neutrons is behind the wall of concrete blocks on the right-hand side. The four grey plates are the support for the truck lifiting columns that allows us to move our experiment vertically to the right height.

July 2023

The report of the first observation of cyclotron radiation from MeV electrons and positrons was accepted in Physical Review Letters

July 2023

After more than five years after the arrival of the first muons, yesterday was the last day of muon operation for the Muon g-2 experiment at FNAL. What a great achievement by a fantastic collaboration!

June 2023

Welcome, Dylan! Dylan is staying with our group for three months as a DAAD RISE sponsored exchange student working on Muon g-2.

May 2023
It was our great pleasure to host the colleagues of the Project 8 collaboration for the first meeting outside of the USA. A lot of fruitfull discussions have been had during three intense meeting days and two additional days of science and technology workshops.

(Picture credit: Kira Karabut and Alec Lindman)

May 2023

Welcome, Utkarsh! Utkarsh is staying with our group for three months as a DAAD WISE sponsored exchange student working on tSPECT.

March 2023

We had a great time at the DPG spring meeting in Dresedn in March. Many outstanding contributions from the
group about Project 8, tSPECT and Muon g-2. And for sure a lot of fun.


March 2023

My colleagues Peter Winter and Simon Corrodi (Argonne National Laboratory) and I are describing the Muon g-2 experiment for a layperson audience in the March edition of "Physik in unserer Zeit".

February 2023

The muon g-2 experiment has just reached more than 21x the raw data volume of its predecessor experiment. while we anticipated at least atwenty-fold increase in the technical design report we submitted in 2015. What a great and challanging time it's been! And it's still going strong.


December 2022

Our very first (anti-)neutrino mass limit based on cyclotron radiation emission spectroscopy has hit the arXiv
With only a cm^3 scale physical detection volume, a limit of mβ<180 eV is extracted from the background-free measurement of the continuous tritium beta spectrum. Using 83mKr calibration data, an improved resolution of 1.66±0.16 eV (FWHM) is measured, the detector response model is validated, and the efficiency is characterized over the multi-keV tritium analysis window.

November 2022

The European Spallation Source ESS will be the world's brightest neutron source located in Lund, Sweden. My colleagues and I have gathered our vision for Particle Physics at this upcoming facility in a paper whose draft is now availble on arXiv.

October 2022

After last week's PSI 2022 conference we took the opportunity to visit two of the numerous experiments with PRISMA+ involvement. Ahmed Ouf (member of the AG Pohl) allowed us into his clean room where he is developping a unique pulsed laser to measure muonic atoms. We returned the favour and gave a tour of the new magnetically shielded room for the n2EDM experiment. Congratulation to Hassan, Noah and Martin for their great poster presentations.










October 2022

Happy 10th anniversary to PRISMA+.
Let this short video take you on a tour through the various questions we are trying to answer within PRISMA+.

October 2022

Welcome to Julian Auler and Brunilda Mucogllava! Julian has joined us a new graduate student on the tSPECT experiment. And Brunilda will perform her PhD research with the Project 8 group.

September 2022

While at Fermi National Accelerator Laboratory my group visited the ANNIE experiment whose PRISMA+
contributions are headed by Prof. Dr. Micheal Wurm. We gladly returned the hospitality and gave a tour of
muon g-2 experiment.

September 2022

Our work to characterize the magnetic field distribution inside the setup that provides the currently
most stringent limit on the electric dipole moment of the neutron is now published in Physical Review A

September 2022

Our work to extend the CRES technology to MeV-scale electrons/positrons was just uploaded to the arXiv.
The first observation of CRES signals at these high energies allows us to push the development of frequency-based searches for chirality-flipping interactions to the next level.

August 2022

Graduate students Hassan Qureshi and Niklas Pfeiffer participated in a workshop about engaging teaching techniques before they attended the 2022 PSI Particle Summer School in Zuoz.

Image source:

August 2022

Postdoc Dr. Larisa Thorne has been featured in the PRISMA+ series "Woran forschen Sie gerade?"

August 2022

Finally back at FNAL to do some preparation work for Run 6 of Muon g-2!
I left FNAL on March 16, 2020 two days before the EU closed its borders due to COVID-19.
Feeling great working again on the magnetic field created by this amazing magnet!

Thank you Saskia Charity for the picture.

July 2022

The muon g-2 result is still puzzeling the physics community all around the world.
Important pregress in calculating the theoretical prediction for the hadronic vacuum polarization contributions
was achieved by my colleahues H. Wittig and H. Meyer here in Mainz and the EMTC collaboration.
A recent article by Davide Castelvecchi, published on, provides a short accessible summary to the still puzzeling situation.

July 2022

Today FB 08 was visited by an enthusiatic group of students from Colombia traveling through Germany to explore opportunities in research and education. It was a pleasure to provide a tour through the TRIGA research reactor faciltiy and to give a presentation about our neutron lifetime expeirment tSPECT. The students also visited the QUANTUM research groups of P. Windpassinger, F. Schmidt-Kaler and Ch. Smorra This travels supoorted through funds of the DAAD.

June 2022

A description of the magnetically shielded room (MSR) for our next generation search for a permanent neutron electric dipole moment just hit the arXiv

This MSR provides the largest ultra-low magnetic field environment in the world.

May 2022

A nice accessible explanation on how the muon beam for the Muon g-2 experiment is generated at Fermilab was rectently published in the Symmetry Magazine

March 2022

Project 8 contibutions to the US Snowmass Process is up on the arXiv for you to read.

March 2022

Congratulations to Dr. Christine Claessens, now at the Univeristy of Washington, for winning the 2022 dissertation award of the DPG section Matter And Cosmos for her excellent thesis and the preseantion at the
award symposium. The laudatio reads „Für ihre Dissertation und den Vortrag mit dem Titel: First tritium β-decay spectrum recorded with Cyclotron Radiation Emission Spectroscopy (CRES). “ . The announcement can be found here.

© Christine Claessens

March 2022

The Project 8 collaboration's contribution to the Snowmass process in the US is on the arXiv

February 2022

Congratulations to Larisa for being a member of the KATRIN collaboration that just published a new upper limit for the effective neutrino mass: < 0.8 eV (90% C.L.). Check it out the Nature Physics paper here.

February 2022

It's my pleasure to welcome Niklas Pfeifer as a new graduate student in my group.
Niklas will dedicate his efforts towards the tSPECT experiment.

January 2022

Our EU-funded Marie Skłodowska-Curie Actions RISE (Research and Innovation Staff Exchange) project aMUSE has finally started after Covid-related delays (PRISMA+ press release). We're looking forward to push the opportunities of
advanced Muon Campus in US and Europe (aMUSE, EU grant agreement: 101006726) with dedicated long-term deployments of staff to FNAL. Details about the project can be found on the project's webpage.


January 2022

Happy New Year to everyone!

December 2021

The description of the absolute magnetic field standard that we use for the muon g-2 experiment was published in JINST and is also available on the arXiv.

December 2021

We are happy to welcome Dr. Evan Adamek in our group. Evan will support us with the tSPECT experimentand comes to us from always sunny Hawaii.

December 2021

Physics World is listing our Muon g-2 result as one of their ten finalist candidates for their Breakthough of the Year for 2021. Project 8 was one of their top ten choices in 2015. Nature has listed us as one of their picks for "The science news that shaped 2021". Science News listes Muon g-2 as "discoveries from 2021, if true, could shake up science".


November 2021

Martin is participating in the Falling Walls Summit 2021. Martin has the privilige to stand in for Chris Polly to present about the Muon g-2 experiment in the "Falling Walls Circle – Wilhelm and Else Heraeus Symposium for Breakthroughs in Physical Sciences". Chris has been nominated as one of the winners of 2021 in the category of physical science.

November 2021

Please join us on November 10th, 2021, 18:30 for a "Parlamentarischer Abend". In this context our exhibition "PRÄZESION" will be presented for the first time: Please have a look at the webpage which also features some content of the exhibition panels.

November 2021

It's my pleasure to welcome Dr. Evan Adamek as a new postdoc in my group.

November 2021

Congratulations to Dr. Kim Ross. A great achievement and very good thesis!

What a great cart representiing tSPECT

And the traditional horse ride was possible again.

September 2021

A decription of the absolute magnetic field standard for the muon g-2 experiment is now on the arXiv

August 2021

We recently took the chance to reconvene nearly the full group to say goodbye to Christian who moved on to
an new position. All the best, Christian!


July 1, 2021 Dr. Larisa Thorne has joined our group as a postdoc on the Project 8 experiment.
Welcome to Mainz, Larisa!

May 3, 2021 We have been visitied by Ingolf Baur from the 3sat science magazine nano
and his cameraperson Philip Flämig for interviews in the context of our new muon g-2
result. The contribution is accessible in the 3sat mediathek.

(Foto: ZDF/3sat nano)

April 30, 2021 A small selection of the press coverage this month.

April 7, 2021 A poster summarizing our results (a high resolution version is available here)

April 7, 2021 Today is the day!

The Physical Review Letter describing our result is available here
The description of the analysis of the magnetic field is published in Physical Review A
The description of the analysis of the anomalous precession frequency is published in Physical Review D

You can watch a recording of the seminar here:

The Symmetry Magazin has published another article on Muon g-2.
Fermilab has also produced a great explanatory video.
The result is featured in Physics Viewpoint
In a Physics Special Edition Jorge Cham, aka PhD comics, explains the experiment.

April 2021 Our Muon g-2 collaboration at Fermi National Accelerator Laboratory will present the long-awaited results of its first physics data taking campaign on April 7th, 2021 (17:00 German time). A Nature news article can be found here. An article in the Symmetry Magazine covered the efforts assemble the magnet and to homogenize the magnetic field in the storage ring. The access link to the presentation will be available in time here.

March 2021 The virtual DPG spring meeting is ongoing. Looking forward to the talks presented by our students and postdoc.

March 2021 Congratulations to Christine Claessens for passing her PhD exam with flying colors. Her thesis work on Project 8 addressed the “Event detection in Project 8 - Detection efficiency and its implications for the
first tritium spectrum recorded with Cyclotron Radiation Emission Spectroscopy”. We are really happy to see
that she will continue to work on Project 8 at CENPA, Seattle.

January 2021 Dr. René Reimann was awarded the GNN dissertation award ( for his doctoral thesis titled "Search for the Sources of the Astrophysical High-Energy Muon-Neutrino Flux with the IceCube Neutrino Observatory" (RWTH Aachen, 2019). Congratulations René!

Photo by Lisa Schuhmacher

January 2021 Carl-Fabian Strid has joined our group as a graduate student on the tSPECT experiment.
Welcome to Mainz, Carl-Fabian!

October 2020 Hassan Qureshi has joined us as a graduate student to work on the Muon g-2 experiment. Welcome Hassan!

September 2020 The European Commission just approved our Horizon 2020 Research and Innovation Staff Exchanges (RISE) 2020 proposal "aMUSE (advanced Muon Campus in US and Europe contribution)". We are looking forward to travel again to Fermilab in support of the muon g-2 experiment after the Covid-19 situation is under control.

July 2020: Project 8 graduate student, Christine Claessens, is featured in the PRISMA+ news series
"Woran forschen Sie gerade?". Christine is reporting about her stay abroad in Seattle and her participation with the TRIMS experiment that just publsihed its result in Physical Review Letters. Congratulations Christine!

June 2020: A new consensus value for the theoretical expectation of the muon g-2 has been released and can be found here. For more detauils about the involvement of JGU physicist in Muon g-2, please read the press release.

March 2020: We are happy to welcome Dr. René Reimann as a postdoc to our group. René is joining in to our efforts in the muon g-2 and Project 8 experiments.

February 2020: We just finished a great beam time with the τSPECT experiment at the UCN source of the JGU TRIGA reactor facility. Way to go, team!

February 2020: Our Measurement of the Permanent Electric Dipole Moment of the Neutron has been published in Physical Review Letters as an Editor's suggestion and is discussed in Physics, in Physics World and in this JGU press release. And here are some press articles about the result on, and

December 2019: Muon g-2 listed by Nature as one of "The science events to watch for in 2020".

September 2019: My group has officially joined the Muon g-2 experiment at Fermilab.