Credits: Image: Photography: Luca Zanier; Artwork: Leonard Köllenberger, Karlsruhe Institute of Technology. Cover Design: Amie Fernandez, Nature Physics
The international KArlsruhe TRItium Neutrino Experiment (KATRIN) located at Karlsruhe Institute of Technology (KIT) has now been the first to constrain the mass of neutrinos to less 1 electron volt (eV) and, hence, has broken an important “barrier“ in neutrino physics. From the data recently published in Nature Physics, a new upper limit of 0.8 eV has been derived for the mass of the neutrino. These results obtained by means of a model-independent laboratory method allows KATRIN to constrain the mass of these “lightweights of the universe” with unprecedented precision. The publication is available here: DOI: 10.1038/s41567-021-01463-1
The results have also been presented in a public outreach event in German. The presentation is still accessible via the following website: https://www.katrin.kit.edu/leicht-leichter-neutrinos.php
Sketch from the illustrator Julie Borgese. She was invited to capture the atmosphere of the symposium and to transform scientific concepts into pieces of art.
After being canceled in 2020 due to COVID-19 restrictions, the 2021 edition of the Paris-Saclay Astroparticle Symposium was organised from October 18 to November 26, 2021 at the Institut Pascal of the Paris-Saclay university. The organisation of this event was made possible thanks to support from P2IO, the P2I graduate school of the University of Paris-Saclay, IN2P3, APPEC and CEA. The symposium was a great success: nearly 230 researchers participated either by being present at the Pascal Institute (about 40 per week, many staying for several weeks) or by participating via videoconference.
The symposium was aimed at researchers specialised in the broad field of astroparticle physics, who were invited to come and work at the Institut Pascal in order to initiate, pursue or finalise research projects and publications. The format of the symposium is particularly well suited for this purpose, with a limited number of plenary sessions dedicated to presentations and leaving a significant amount of time reserved for joint work and informal discussions.
Due to the cancellation of the 2020 edition it was decided to extend the duration from the usual 4 to 6 weeks in 2021. Each week focused on specific topics and followed a similar outline: moderated by one or more specialists, informal discussions of about 2 hours on a specific topic triggered very fruitful exchanges and initiated joint works. One day per week was dedicated to presentations by participants who wished to present their work.
The following topics were discussed during the symposium (the details of the different sessions are available on the event website https://indico.ijclab.in2p3.fr/event/7119/):
Week 1: Galactic Cosmic Rays
Week 2: Ultra-High Energy Cosmic Rays
Week 3: Dark Matter: Theories
Week 4: Dark Matter: Theories versus Experiments
Week 5: The transient sky (GWs and compact objects, multi-messenger astronomy)
Week 6: Gravitational waves, theoretical point of view
In addition, a series of seven lectures for the general public, given by well-known external speakers, was organised. These lectures took place in the evening at the Institut Pascal and were a great success. Finally, an illustrator was invited to capture the atmosphere of the symposium and transform certain scientific concepts into pieces of art. A first sketch is shown below.
The 2022 edition of the Paris-Saclay Astroparticle Symposium is already in preparation!
Mark your agenda: it will take place from October 31 to November 25, 2022 at the Institut Pascal of the Paris-Saclay university.
Composition of the Paris-Saclay Astroparticle Symposium 2021 organising committee:
Fabio Acero (AIM, CNRS/INSU)
Philippe Brax (IPhT CEA)
François Brun (CEA/IRFU – Department of Particle Physics)
Olivier Deligny (IJCLab, CNRS/IN2P3)
Carla Macolino (IJCLab, CNRS/IN2P3)
Yann Mambrini (IJCLab, CNRS/IN2P3)
Fabian Schüssler (CEA/IRFU – Department of Particle Physics)
List of scientific symposia :
The implications of discovery of PeVatrons, by Zhen Cao
Perspectives in Astroparticles, by Andreas Haungs
Searching for ultra light dark matter and gravitational waves with atom interferometers, by John Ellis
Strategies for European astroparticles, by Gianfranco Bertone
Multi-messenger astronomy including gravitational waves, by Marica Branchesi
The Cherenkov Telescope array and its science, by Werner Hofmann
List of public lectures :
Physics in science fiction films, by Richard Taillet
Why the sun shines, by Roland Lehoucq
What is the vacuum full of, by Étienne Klein
A history of the Universe: from the Big Bang to the present day and beyond, by Yann Mambrini
Seeing and hearing black holes, by Alain Riazuelo
The arrow of time, from molecular billiards to the dance of stars, by Cédric Villani
Thirty years of progress in astrophysics, by Hervé Dole
The “Low-latency alerts and data analysis for Multi-messenger Astrophysics workshop”, organized with the support of the H2020 funded project AHEAD2020, the APPEC consortium, IN2P3, APC Laboratory and EGO was held on 13-14 January online. The workshop, the first of a series, gathered over 150 participants and aimed to provide an overview of the existing and future developments from a data analysis perspective of the space-based and ground-based infrastructures, identify and discuss technical issues and foster new interactions and community building around the multi-messenger data analysis science and tools. Together with the future events on this topic of paramount importance to be announced in the first half of the year by the committee, the long term goal is to contribute to the emergence of a common path towards a more integrated approach for the multi-messenger astrophysics data analysis. The contributions can be found here: https://indico.in2p3.fr/event/25290/contributions/
Interview with the APPEC Scientific Advisory Commitee Chair Sijbrand de Jong about the review process
The (European) Astroparticle Physics community is invited to provide feedback on the draft APPEC mid-term review of the Astroparticle Physics Strategy 2017-2026. The APPEC SAC, with its chair Sijbrand de Jong, has been preparing this preliminary review over the last few months and has now made it available to the community. The report as well as the feedback form are both accessible at https://indico.desy.de/event/32140/overview – feedback will be possible until January, 21st, 2022. It will be further discussed during the Berlin Town Meeting in June, after which the final report will be prepared. In this interview, Sijbrand de Jong gives us an insight into the entire process.
You have been coordinating the review process over the last months. What is your intention with the current draft document?
We are now half-way the 2017-2036 period of the current European Astroparticle Physics Strategy and a lot has happened since then. Hence, this is a good time to take stock concerning the present strategy and to see if corrections on the course are needed and to start thinking about the European Astroparticle Physics Strategy in the period after 2026. Therefore, the APPEC General Assembly (GA) has asked the Scientific Advisory Committee (SAC) to organise an update of the strategy. The SAC would like to involve the entire Astroparticle Physics community in Europe and beyond in the update process. The final draft of the strategy update that will be offered to the GA for endorsement will be based on the outcomes of a Town Meeting to which then entire community is invited and which will be held in Berlin on 9 and 10 June 2022. To prepare both the agenda, the discussion form and the content of this meeting, the SAC is preparing a document to review the current situation and to indicate new developments since 2017 and topics for discussion. Such a document will help to structure the discussion and will allow us to arrive at a good conclusion after two days of gathering. The SAC consists of some very knowledgeable people, but it falls short compared to the intellectual capacity of the entire APP research community. In the preparation of this review, the SAC therefore requests the help of the entire community to arrive at a balanced document as input for the discussions in Berlin. To structure the input from the community the current draft review serves as a framework where we hope we already give a decent summary of the status and developments and list of discussion items, and we ask for feedback to complete and refine the review.
Localization of the gravitational-wave, gamma-ray, and optical signals for the binary neutron star merger GW170817. (From B. P. Abbott et al 2017 ApJL 848 L12)
What you consider as major changes since the publication of the roadmap in 2017?
In particular in multi-messenger astronomy things move forward fast, but also our knowledge on particle physics is progressing steadily. There are lots of experiments and observatories announced as desirable in the current strategy that are being realised. The use of machine learning is gaining terrain rapidly and will also be very important to our research field. With the experiments getting bigger and more expensive in time, the pooling of resources and the availability of central research infrastructure gains importance to the point that going to a next level of organisation and coordination seem inevitable. There have also been major developments in society at larger and in our scientific surroundings. Diversity, Equity and Inclusion and the care for all our researchers must be on the agenda. Some of these topics were not much addressed in the current strategy, but the SAC feels they ought to be addressed from now on.
Who should give feedback and how?
We are reaching out to the entire APP community. All individuals are invited to give feedback. It is important that every voice is heard. In addition, it is also particularly useful to receive the feedback of collaborations and national communities. Collaborations often already have their own strategy, sometimes even involving a follow-up experiment. National communities are usually the closest to the sources of our resources. The National roadmaps have a real impact on what we can do in the European context. There is a fort and back between the European strategy and the national strategies. One may hope that the national strategies align with the European strategy, but this is only possible if the national strategies are considering the European strategy. Of course, we hope for feedback from committees and boards that represent the research fields bordering APP, such as particle physics through e.g. ECFA and nuclear physics through e.g. NuPECC. There is much overlap with these communities and real synergy is possible, the Joined ECFA, NuPECC, APPEC Seminars are a good example for meeting and starting joint projects.
What do you expect from the community feedback?
Most likely we will have missed things and made some factual mistakes. It is important to get these potential distractions out of the way to keep the discussions in Berlin focussed and effective. Despite its length, the document is relatively short on any particular experiment, observatory or development. We are trying to keep the document as concise as possible, while maintaining a balance in the amount of information for each subject and issue. We have probably succeeded when everybody feels that we are too short on their darlings.
What are the next steps after the feedback deadline?
After gathering all the feedback, the SAC will adapt the review to be as comprehensive and correct as possible. This final review, after being endorsed by the GA, will be made public well in advance if the Berlin Town Meeting. At the same time as finalising the review, the SAC will also draw up the agenda for the Berlin meeting with all the information of what the community thinks is. We will also carefully consider all suggestions for “burning questions” that can be given in the feedback form. This is a very important part of the feedback form.
How will you include the discussions taking place during the Town Meeting in the final document?
Ideally, the strategy update document will be much shorter, and hence it will contain much less detail than the review document. Yet, all relevant information from the Town Meeting will have to be included. This is a daunting challenge, to which the SAC will set itself over the summer of 2022. Basically, it means that the strategy update will be written from scratch, following the format of the current strategy document. The strategy update will also contain many more pictures than the single one in the current review document. The SAC wanted the review document to be picture free, but the only one included replaced a lot of text to explain the interrelations of all sorts of neutrino properties and their measurements and is therefore included. Not as an illustration of the text, but as the replacement of a potential lengthy text paragraph.
When the final document will be published and what is your goal with this review?
During the process this document will serve as the basis of our discussion in the Town Meeting and as one of the basic inputs for the strategy update document. It will also serve as the basis for the deliberations of the SAC on the programme for the Berlin Town Meeting and be a lead for structuring the discussions during this meeting. It is therefore a pivotal working document. The review and the talks and summaries of the Town Meeting will be made public. After the completion of the update process, they will serve both as documentation of the process itself and as background information of the strategy for those who really want to dig deep.
Sijbrand de Jong was trained as an experimental particle physicist and worked on deep inelastic neutrino, muon, and electron scattering and electron-positron, antiproton-proton and proton-proton colliders, before turning to ultra-high-energy cosmic ray science. He worked on both instrumentation, data analysis and phenomenology in particle and astroparticle physics. Presently, he is a member of the Pierre Auger Collaboration and GRAND Collaboration, specialising in radio detection of ultra-high-energy cosmic particles. He held several management and governance positions, e.g., member of the LHC committee, and CERN Council president and presently is the dean of the Faculty of Science of Radboud University.
The International Year of Basic Sciences for Sustainable Development 2022 was initiated by Michel Spiro, President of IUPAP who proposed that scientists from all the basic disciplines should mobilise, in order to show the importance of their contributions to progress towards the Sustainable Development Goals.
An IYBSSD should show the ways in which curiosity-driven research is vital to ensure good health for all, to overcome hunger, to fight climate change, to preserve terrestrial and marine biodiversity, but also to increase world peace and fight inequalities. Together, researchers from all fields will reach out to the general public and to decision-makers, both public and private, to support the development of the basic sciences, especially in parts of the world where they are still insufficiently developed.
APPEC now joined the IYBSSD as an official partner. All partners advise and decide about the IYBSSD 2022 international program and will contribute to the international organization with their own actions and programs about sustainable development but also by funding and contacts with their members and partners.
Starting in May 2020 with an EPPSU mandate to ECFA to develop a raodmap for detector R&D efforts in Europe, ECFA implemented a process to deliver such an document. This task was now succefully finished and the 2021 ECFA Detector Research and Development Roadmap was just published.
The roadmap process was organized in six technology-oriented Task Forces, Gaseous Detectors, Liquid Detectors, Solid State Detectors, Photon Detectors and Particle Identification Detectors, Quantum and Emerging Technologies, Calorimetry, and three transversal Task Forces across all technologies and facilities, Electronics and On-detector Processing, Integration, and Training.
During several topic-specific Symposia the community and experts from other fields were involved inthis process. An Advisory Panel with members from different fields helped to establish the communication between conveners and experts in each Task Force and the experts in their respective fields. Also APPEC was asked to provide experts for each Task Force who had been contacted by the convenors to evaluate possible links of the Task Force content to Astroparticle Physics.
On 18th November 2021 the Roadmap Document was approved by Plenary ECFA and as final step presented to CERN Council on 10thDecember 2021. The Synopsis and the full document are now available here: https://cds.cern.ch/record/2784893
We want to thank our ECFA colleagues not only for the successfull compilation of this very useful and forward-looking document, but also for the good cooperation with APPEC to identify and support possible synergies in detector developments.
On 8 November ETpathfinder was opened in Maastricht in a festive ceremony by the demissionary Minister of Education, Culture and Science of the Netherlands Ingrid van Engelshoven. ET pathfinder serves as a testbed to develop new technologies for future gravitational wave detectors, in particular the Einstein Telescope (ET).
The ETpathfinder is built at Maastricht University involving several European institutions as explained by Stefan Hild, project leader of ETpathfinder: “We started ETpathfinder with 15 partners from the Netherlands, Belgium and Germany. Universities and research institutes from France, the UK and Spain have since started to contribute as well. It is great to see all this international expertise come together here in our facility.”
The facility is a huge cleanroom where various kinds of laser interferometers can be set up over the next 20 to 30 years. Despite several towers which contain all kinds of equipment there are ‘arms’ consisting of vacuum tubes of 20 meters long. Although they are too short to actually measure gravitational waves they are sufficient for the development and testing of different kinds of technologies and their interplay. This includes for example new cooling techniques, mirror coatings and lasers, which will be developed together with high-tech companies. The resulting innovations are expected to find other uses in industry as well.
The construction of ETpathfinder in Maastricht strengthens the border region’s position as a candidate location for the the Einstein Telescope and is an important asset to science in Netherland as stated by van Engelshoven: “We strengthen both the development of large-scale scientific infrastructure and the ambition to conduct fundamental research. I am pleased that I was able to contribute to this instrument together with the other partners.”
Left: Professor Stefan Hild, project leader of ETpathfinder and ‘demissionary’ minister Van Engelshoven (OCW).
Right: With a push of the button, Ingrid van Engelshoven officially opened ETpathfinder from inside the cleanroom.
Credits: Philip Driessen, Maastricht University.
A 3D render of ETpathfinder. Credits Marco Kraan, Nikhef
The European Astroparticle Physics Strategy 2017-2026 was adopted by the APPEC General Assembly in 2016. Since then, there have been many developments both in the Astroparticle Physics research field and in the wider world.
In the coming time, APPEC undertakes a mid-term update of the European Astroparticle Physics Strategy, with the aim to establish such an update in fall 2022.
The (European) Astroparticle Physics Community will be closely involved in this update. To this end, a Town Meeting is being prepared for 9 and 10 June 2022 in Berlin, at which occasion all relevant aspects of the strategy will be discussed.
In preparation of this discussion, the APPEC Scientific Advisory Committee (SAC) is preparing a mid-term strategy review document to be serving as framework for the organisation of the Town Meeting and to serve as input for the discussions themselves.
A first draft of the mid-term review is now available here. This document is a DRAFT and not the final document. It serves for the APPEC SAC to receive feedback from the community concerning the accurateness and completeness of the document. Please note, that developments are going fast and that some notions in the report may have been outdated before the ink dried up.
We invite you to give feedback to this document through a form provided on this page. There the form is accessible through the “Feedback” button on the left, or the “Fill out the survey” link at the bottom of the page. Feedback can be given as National Community, Collboration or Individual. Please check the appropriate box.
Feedback can only be provided as plain text. Of course, hyperlinks can be quoted in this text to properly document your response. Multiple feedback submissions are possible, but one comprehensive feedback text will be appreciated.
We explicitly solicit to suggest a burning question that is not yet addressed in the draft mid-term review and that you think should really be discussed during the Town Meeting.
Deadline for your feedback is Friday 21 January 2022.
Your feedback will be used to compile the final APPEC SAC mid-term strategy report that will be released well in time for the Town Meeting on 9-10 June 2022. For transparency, your feedback will become available publicly after when the final SAC mid-term review will be submitted to the community as input for the Town Meeting.
The input from the Town Meeting will serve as input for the Strategy Update document that the APPEC SAC will prepare for submission to the APPEC GA after the 2022 summer holidays. The GA will then release it as the European Astroparticle Physics Strategy 2022-2026 Update.
The European Astroparticle Physics Strategy 2022-2026 Update will also serve as an input to the process to establish the new European Astroparticle Physics Strategy after 2026.
From Sep. 29th until Oct. 1st the LNGS Laboratories hosted an international, hybrid workshop on Neutrinoless Double Beta decay focussed on a common strategy of European and North American agencies on that topic, see https://agenda.infn.it/event/27143/ .
The main projects and experiments included in the APPEC roadmap and the DOE Portfolio Review, the corresponding science, on-going R&D activities for even more ambitious future projects, as well as the capabilities of the relevant Underground Laboratories have been discussed at this workshop. Four major projects have been discussed in depth: CUPID, nEXO, LEGEND and NEXT. CUPID, LEGEND and nEXO were part of the DOE Portfolio Review, while CUPID, LEGEND and NEXT are parts of the APPEC Roadmap on Neutrino-less Double Beta Decay.
After three days of fruitful and deep discussion, the representatives of several European and North American funding agencies, Ministerial representatives and Laboratory Directors have met in a closed session. They unanimously agreed that the strong scientific motivation and the need to cross-check any potential signal with different isotopes justifies the effort to support three experiments, CUPID at Gran Sasso, and LEGEND and nEXO, where one should be located in North America and one in Europe.
The NEXT experiment is highly valued and considered as a future development, but the general consensus is that it then needs to be discussed further once its scalability to large detector masses has been demonstrated.
All participants are aware that this ambitious programme will require additional funding beyond that already secured. Therefore, discussions between the agencies and the scientific community will continue.
Ideally, the strategy update document will be much shorter, and hence it will contain much less detail than the review document. Yet, all relevant information from the Town Meeting will have to be included. This is a daunting challenge, to which the SAC will set itself over the summer of 2022. Basically, it means that the strategy update will be written from scratch, following the format of the current strategy document. The strategy update will also contain many more pictures than the single one in the current review document. The SAC wanted the review document to be picture free, but the only one included replaced a lot of text to explain the interrelations of all sorts of neutrino properties and their measurements and is therefore included. Not as an illustration of the text, but as the replacement of a potential lengthy text paragraph.
Starting in May 2020 with an EPPSU mandate to ECFA to develop a raodmap for detector R&D efforts in Europe, ECFA implemented a process to deliver such an document. This task was now succefully finished and the 
From Sep. 29th until Oct. 1st the LNGS Laboratories hosted an international, hybrid workshop on Neutrinoless Double Beta decay focussed on a common strategy of European and North American agencies on that topic, see 
