In January 2025, CERN Director-General Fabiola Gianotti attended the World Economic Forum’s annual meeting in Davos, Switzerland. She joined world-renowned cellist Yo-Yo Ma on stage for a discussion on the connections between science, nature and art, before accompanying him on the piano for a duet of “Le Cygne” by Camille Saint-Saëns.

During the event, Gianotti highlighted CERN’s successful model of global collaboration.

“Only by uniting brilliant minds from around the world can we hope to find answers to the most complex and profound questions,” she said. “Both physics and music are forms of exploration. Arts, science, philosophy – it’s all culture, they are what make us human.”

During her time as CERN Director-General, Gianotti has been invited to Davos on several occasions, with contributions ranging from participating in debates to co-chairing. And this year’s contribution is not her first time collaborating with Ma. You can watch their CERN Science Gateway performance from December 2023 here.

Data confidentiality, while not paramount for CERN’s physics data, is still important when it comes to protecting sensitive contractual, financial, personal, radiation- and science-related documents and files. Just because CERN is “academic”, this does not and must not imply that data confidentiality is not an issue. On the contrary, it is our joint obligation to keep secret what is intended to be seen by just a few privileged eyes. Otherwise, lost data might become a media nightmare for CERN, or an operational risk, with both reputational damage and potential legal and contractual consequences. That’s why a dedicated Data Governance Office has been created. Before they ask, have you thought about how you handle your private and professional data? Do you let it walk away?

Or do you ensure the confidentiality of your private data on your portable devices (laptop, tablet, smartphone)? How do you store that data? How do you make sure it’s properly backed up? Of course, the first step is access protection – making sure that nobody but you (and your trusted peers) can access your portable device. Password protection. Fingerprint reading. FaceID. Whatever, as long as it is “strong” enough. The next step is local data encryption, if possible. Your Windows computer comes with “BitLocker” – just switch it on (and don’t lose its recovery code). Ditto for your MacBook – “FileVault” is your friend. For Linux, Ubuntu is one example of encryption available during set-up.

Things get a bit more complicated when it comes to backing up using removable media, e.g. flash drives, pluggable hard disks or your “network-attached storage” at home. Ideally, they come with an intrinsic encryption method already installed and ready for you to employ (once again, don’t forget the recovery code). If this is only for back-up, physical protection in a physical safe at home, under lock and key, might suffice. But if the purpose is sharing data with a third party, encryption of any confidential data is a must. Note that email communication is usually not encrypted and is therefore as unprotected as a snail-mail handwritten postcard. As an alternative to encryption, you can use platforms like Dropbox or Google Drive to upload your files and make them available for download via a shared URL (which you should communicate secretly). Of course, you need to trust those platforms’ security policies and their data privacy statements. CERNBox can be a valid alternative as long as your personal usage is not excessive.

For professional data, of course, CERNBox or any other CERN-managed storage system is the best and ONLY official way to share data with your colleagues. The easiest approach is to upload and share by granting access to the relevant CERN computing accounts, always following the “principle of least privilege”. Only those who need to know should be able to access those professional documents. We will discuss this more in a forthcoming Bulletin article on data handling.

And if you happen to use a CERN-owned computer (i.e. paid for via a CERN budget code*), it is imperative that this device has local storage encryption enabled. The Computer Security Office will enforce this in 2025 following a recommendation of the 2023 audit on CERN computer security. In addition, an upcoming Subsidiary Policy will require that local USB storage devices not be used for any professional data classified as other than “public”. Last but not least, remember that sharing (unencrypted) documents via email in no way preserves confidentiality. Just don’t do it unless you have encrypted your files first. Otherwise, your data might just walk away…

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*… but not a “Team” account.

Do you want to learn more about computer security incidents and issues at CERN? Follow our Monthly Report. For further information, questions or help, check our website or contact us at Computer.Security@cern.ch.

In February 2024, the SCE, SY and BE departments launched a pilot project for a new shuttle service between the Meyrin and Prévessin sites – the Meyrin–Prévessin Express. This reinforced version of Circuit 5 increased shuttles during peak times, including over lunchtime.

After one year of service, the results and feedback are very positive. The Meyrin–Prévessin Express has therefore now been made part of the official CERN shuttle service.

Furthermore, to extend its efforts to develop and adopt sustainable and low-carbon solutions for the campus, the SCE department will replace the whole shuttle fleet by 100% electric vehicles from 1 February.

[This article was updated on 4 February 2025]

At its second meeting, the Computer Security Board formally approved several Subsidiary Rules to the Use of CERN computing facilities (Operational  Circular No. 5, OC5) related to Identities, Authentication & Authorisation (IAA). The approved rules (IAA2/3/4/6/7) are now documented on the website of CERN's Computing Rules.

At its third meeting, the Computer Security Board formally approved several Subsidiary Rules to OC5 related to Endpoints (EPT) and Software Restrictions (SWR). The approved rules (EPT1/2/4/5/6 and SWR2/3) are now documented on the website of CERN's Computing Rules.

At its fourth meeting, the Computer Security Board formally approved several Subsidiary Rules to OC5 related to Identities, Authentication and Authorisation (IAA5), IT Service Operations (OPS3) and Networking (NET3/4/8/9). All the approved rules are documented on the website of CERN's Computing Rules.

For more information, read this article: Computer Security: Security Rules revised

In application of Article R V 2.03 of the Staff Regulations, the internal tax scale has been adjusted with effect on 1 January 2024.

The new scale may be consulted via the CERN Admin e-guide.

The notification of internal annual tax certificate for the financial year 2024 takes into account this adjustment.

The United Nations has declared 2025 the International Year of Quantum Science and Technology (IYQ). Kicking off about 100 planned events worldwide was an opening ceremony on 4 February at the UNESCO headquarters in Paris.

Enrica Porcari, Head of CERN’s Information Technology department, attended the opening ceremony: “What matters is how much the planned initiatives will move the needle towards a broader public awareness about the profound implications that quantum science and technology already have and, most importantly, will soon have on society.”

The CERN-based Open Quantum Institute (OQI) is a participating partner in the IYQ and a leading project coordinator for key events around Geneva throughout the year.

Quantum is also the central theme for CERN’s 2025 public events season in CERN Science Gateway, supported by the CERN & Society Foundation.

The public events season begins with De Temps en Temps on 11 February, the International Day of Women and Girls in Science. Physicist Yasmine Amhis from the LHCb experiment and the DoniSSi string quartet invite you to explore the mysteries of time in all its facets. Find out more and register here: https://indico.cern.ch/e/detempsentemps and discover the full programme here: https://visit.cern/events.

CERN’s core business is fundamental science.  However, the Laboratory’s technology and know-how have the potential to drive innovations in a variety of fields, often through collaborations with industrial partners.

If you are working on an exciting technology and wondering how it could make an impact outside of CERN, we encourage you to apply for one of the two funding schemes that help bridge the gap between research and industry: the Knowledge Transfer (KT) Fund and the Medical Applications (MA) Budget. These mechanisms provide resources to help take early-stage, innovative projects from the Laboratory to society.

To be considered, a project must be based on CERN technologies, submitted by a member of the personnel and approved by the latter’s department head. Grants from the KT Fund and the MA Budget can cover material and equipment costs, as well as allowing CERN teams to hire additional team members, typically technical or PhD students or graduates to support the project’s activities. The department must agree to cover the salaries of the applicants. The KT group is available to help you to assess the technology and seek external partners, such as companies, hospitals or universities.

If your technology has the potential for applications in healthcare, you should apply for funding from the MA Budget. Before making your submission, you must present your proposal – even if it’s not yet finalised – at one of the upcoming CERN Medical Applications Project Forum meetings on 12 February or 12 or 19 March 2025.

Please contact kt.medicalapplications@cern.ch as soon as possible to book your slot. The full process is explained here: https://kt.cern/funding/ma-budget

If you are targeting applications outside the healthcare field, please apply for funding from the KT Fund by following the instructions detailed here.

Complete applications must be submitted by 31 March 2025. Applicants will then present their proposals to the selection committee on 8 May 2025.

We encourage you to contact your Knowledge Transfer Internal Network (INET) representatives or the Knowledge Transfer group (kt@cern.ch) as early as possible to discuss opportunities.

For more information about previously funded projects, please consult the list on the KT website.

Atoms are made up of protons and neutrons orbited by electrons, which are thousands of times lighter. But that’s not the whole story. Protons and neutrons are themselves composed of trios of particles called quarks, which are only a little heavier than the electrons and contribute less than 1% to the mass of protons and neutrons. So where does the other 99% of the mass of protons and neutrons – and thus of the visible Universe – come from? The answer is “glue” or, more specifically, particles called gluons, which stick the quarks together. Although gluons are massless, their energy provides the other 99% of the mass of protons and neutrons via Einstein’s famous equation E=mc².

However, much remains to be understood about gluon dynamics. The chief experimental challenge is to observe the onset of gluon saturation – a dynamic equilibrium between the splitting of gluons into pairs of gluons and gluon recombination, in which two gluons combine to become one.

In the latest issue of the CERN Courier, Daniel Tapia Takaki of the University of Kansas describes how ultraperipheral, or near-miss, collisions at the Large Hadron Collider (LHC), mediated by high-energy photons, are shedding light on gluon dynamics and could reveal gluon saturation.

Find out more in Takaki’s CERN Courier article and in this article from the ALICE collaboration.

11 Feb 12:00 | At CERN | Restaurant 1 | Women in Technology & Aid For All | EN&FR
Women in Technology (WIT) cake sale in support of Aid For Allon the occasion of the International Day for Women and Girls in Science

11 & 13 Feb 12:00 | At CERN | Restaurants 1, 2 & 3 | Diversity & Inclusion Programme | EN&FR
CERN D&I Programme awareness campaign: learn more about their initiatives, including 25 by ’25

11 Feb 20:00 | Knowledge Sharing | CERN Science Gateway | Public Events | FR
De Temps en Temps– part of CERN's Quantum! season

13 Feb 13:30 | Knowledge Sharing | 160/1-009 | IPPOG & WIT | EN
Special Particle Physics Masterclass for CERN Personnel

14 Feb 13:30 | Knowledge Sharing | CERN Library | Archives, Library and Open Science events | EN
The Voice of Science – "Hollywood physics" by Professor Carsten Welsch

18 Feb 11:00 | Knowledge Sharing | 30/7-018 - Kjell Johnsen Auditorium | Knowledge Transfer | EN
KT fund and MA budget information session

20 Feb 11:00 | Knowledge Sharing | 40/S2-A01 - Salle Anderson | Women in Technology | EN
Particle by Particle: Building Our Equality. A forward-looking discussion uniting women across all generations at CERN

21 Feb 11:00 | Knowledge Sharing | 61/1-009 - Room C | Knowledge Transfer | EN
KT fund and MA budget information session

21 Feb 14:00 | Knowledge Sharing | Council Chamber | Open Source Program Office | EN
Contributing to Open Source

26 Feb 11:00 | Knowledge Sharing | 874/1-011 | Knowledge Transfer | EN
KT fund and MA budget information session

4–6 Mar | Computing | Council Chamber | CERN openlab | EN
2025 CERN openlab Technical Workshop

10–14 Mar | Accelerators | Ferney-Voltaire | CERN Accelerator School | EN
Basics of Accelerator Physics and Technology

14 Mar 14:30 | Knowledge Sharing | Online | CERN Alumni | EN
Moving Out of Academia to Data Science & Analytics (2nd edition)

20 Mar 20:00 | Knowledge Sharing | CERN Science Gateway | Public Events | FR
Les Dieux et le Père Noël : vers une solution quantique– part of CERN's Quantum! season

21 Mar 14:00 | Knowledge Sharing | Online | Micro-Talks | EN
#15 Critical Thinking: Challenge Assumptions, Reframe Issues

Registration now open

15–27 Jun | Accelerators | Bulgaria | CERN Accelerator School | EN
Pushing the Limits: Intensity Limitations in Hadron Beams

17–26 Jun | Experiments | Lithuania | ISOTDAQ | EN
ISOTDAQ 2025 – International School of Trigger and Data AcQuisition

23–27 Jun | Physics | Venice, Italy | Update of the European Strategy for Particle Physics | EN
Open Symposium of the 2026 Update of the European Strategy for Particle Physics

This is a curated list of events relevant to the CERN community.
More events are available here: home.cern/events
Indico also shows ALL events happening today, this week and in a calendar view. 

If you would like your event to appear on an upcoming Bulletin events list, please contact bulletin-editors@cern.ch

On 11 February, CERN celebrates the International Day of Women and Girls in Science. To celebrate diversity and representation in STEM-related fields, we asked six female scientists from CERN to share their stories and their advice for the future generation of scientists.

Irene is a Spanish theoretical physicist working in the Theory department at CERN. Her research interests include string theory, theoretical cosmology and particle physics.

Sofia is a Greek accelerator physicist with a background in engineering, working at the CERN Control Centre– the nerve centre of the CERN beam systems.

Eva comes from Austria and is currently the run coordinator of the CLOUD experiment, which studies atmospheric and climate science.

Maria is a Spanish computer engineer in the IT department and a member of the steering committee of Women in Technology at CERN.

Asar is Palestinian and she’s a non-Member State doctoral student at ISOLDE, which studies the properties of atomic nuclei, with applications in fundamental studies, astrophysics and material and life sciences.

Marta is a Hungarian and Romanian engineer and leads the work package for the High-Luminosity LHC (HL-LHC) Inner Triplet String.

The Future Circular Collider (FCC) Feasibility Study has also been highlighting the essential role of women in science in a series of 12 videos featuring female scientists, from physicists tackling fundamental theoretical questions to engineers developing cutting-edge detector technologies and more. By highlighting their backgrounds, expertise and passion, this series seeks to inspire the next generation of scientists while highlighting the importance of diversity and inclusion in scientific research.

The European Intergovernmental Research Organisation Forum (EIROforum) is a consortium that unites eight of Europe’s largest intergovernmental research organisations to promote the quality and impact of European research. CERN joined EIROforum in 2001 and has since made concerted efforts to promote science education and inspire young people to pursue careers in science, technology, engineering and mathematics (STEM). To celebrate the International Day of Women and Girls in Science, the EIROforum members participated in the social media #PassThePhone challenge to showcase the incredible work that nine women are doing across STEM fields.

CERN is celebrating the International Day of Women and Girls in Science by shedding light on the variety of career paths for women in STEM. It is an opportunity to remind ourselves that further efforts are needed to ensure gender equality in science, technology, engineering and mathematics.

In 2021, the CERN Diversity & Inclusion programme launched the “25 by ’25” strategy, an aspirational target-based initiative to boost the gender and nationality diversity of CERN’s staff and fellow population by 2025. Find out more about 25 by ’25 here.

2025 Exercise

John Pym and Nick Ziogas have drawn up the following list of staff members from among whom the Chairperson of the Board may be chosen when required:

• Sophie BARON / EP
• Kandy MITCHELL / PF
• Johan BREMER / TE
• Alberto PACE / IT
• Ilias EFTHYMIOPOULOS / BE
• Gabriel THIEDE / FAP
• Quentin KING / SY
• Giovanna VANDONI / ATS
• Sebastian LOPIENSKI / IT
• Andre HENRIQUES / HSE

At last. With Christmas another 300 days away, the season of the “free” is over. Or is it? Not all software, even if labelled “open source” or “free”, is free of charge. The same is true for photos “found” in a web search. They might all be subject to licence fees and copyright. In fact, the CERN Computer Security Officer still receives repeated invitations from companies to “regularise” our mutual licence conditions. On the other hand, in CERN’s academic environment, licence conditions become a PhD in themselves. Let’s delve deep.

Licence conditions are complex – too complex IMHO – but perhaps deliberately complex to make some easy money for the licence holder and blind the user to whether or not it is free, creating doubt and uncertainty, leading them to pay in the end, wary of falling into the trap of licence infringement. And the conditions depend on so many factors: professional vs private use; used by a few, a team or many; used at CERN, or on a CERN-owned device or with a CERN email address. But what do the licence conditions really entail?

Professional vs private: This is the easiest one. According to many terms of use, “private use” is when it is entirely private and never used for any professional purpose. For example, using “TeamViewer” to connect remotely to your Grandma’s PC is fine, but if you use it from your personal laptop at home to connect to your personal PC at CERN, it is not private anymore, even if that connection is “just” to edit holiday pictures. The same holds true for software used to edit those holiday photos when you edit them on a CERN PC. Once “CERN” hardware (or your employer’s hardware) is involved, it usually isn't “private” anymore.

Team size: Some software, like “Slack”, can be used for free but also offer a “Pro” subscription for “small teams”. But what “small” and “team” means, they don’t really say. The Computer Security team is small (eight fine people using lovely Mattermost), as are many other teams at CERN. But if you include people from all over the Organization, “small” becomes “large”. And the licence conditions change drastically.

Locality: And then there is “locality”. The conditions may state that the software may only be run, for example, at CERN. What does that mean? On a device connected to the CERN network with an IP address assigned to CERN? What about CERN Terminal Servers running that software or me remotely connecting to a PC in my CERN office? Does it run at CERN or outside since it is ported to my display abroad? What about having it installed on a device owned by CERN but connected somewhere else? Can or can’t I use that software on my CERN laptop from home? Or while waiting in the airport lounge? Or should the airport pay the licence for me (which they won’t)? Or my internet service provider? Few licence conditions are crystal clear on that.

In addition, we have had cases where the “free” software was registered with a CERN email address. But what does that imply? Is CERN liable? Is Google liable if I register with an @gmail address? I think you get the idea.

As far as CERN is concerned, CERN IT acts as a service provider to its community, providing network connectivity, (virtualised) computing clusters, databases and storage spaces. And CERN provides a plethora of IT services and applications with the corresponding licences (e.g. for Windows, Linux,  macOS, control systems). Most of those services and applications come conveniently free. Some others might require a contribution to their costs. Additional services and software may be purchased via an EDH purchase requisition (DAI) but are subject to the approval of the CERN Cloud or Software Licence Offices, the Web Governance Board, the CERN Electronics Engineering Committee (ELEC) or the Computer Aided Engineering Committee (CAEC) in order to avoid creating a cacophony of similar solutions and spending money on software that has already been purchased centrally.

So, before using any cloud service, software or application, check its licence conditions. Similarly for any software you purchased via your institute, university or even privately: can it be used (for free) for professional purposes at CERN? Please check with the CERN Cloud or Software Licence Offices if in doubt. Because very often “free+free” can become costly...

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Do you want to learn more about computer security incidents and issues at CERN? Follow our Monthly Report. For further information, questions or help, check our website or contact us at Computer.Security@cern.ch.

Courtesy of the State of Geneva, Unireso travel passes for the Geneva public transport network (TPG) are now available free of charge for the following people:

• 18–24-year-olds (inclusive) who live in the Canton of Geneva and:
  • are enrolled in an educational establishment in the Canton of Geneva
  • are enrolled in an educational establishment outside the Canton of Geneva
  • earn less than 50 000 CHF per year
• 18–24-year-olds (inclusive) who live outside the Canton of Geneva and:
  • are enrolled in an educational establishment in the Canton of Geneva
• under-18-year-olds who live in the Canton of Geneva

Please note that if you are living outside the Canton of Geneva and are not affiliated with a Geneva-based educational establishment, you are not entitled to a free pass.

To get your travel pass, you will need to provide proof of your status. This includes proof of address for those living in Geneva and, for students, an education certificate from your institution (not CERN).

Please note that CERN will not sign these certificates. This is because CERN is not an educational establishment and CERN internships and studentships include a subsistence allowance to cover living expenses, including travel.

Applications for the free travel pass can only be made online (if you have a SwissPass) or in the Rive, Cornavin and Lancy TPG ticket offices. For more information, visit the TPG website. You can also buy and renew TPG tickets and other passes at the CAGI cultural kiosk in CERN’s Main Building.

While the year-end technical stop (YETS) is still in full swing in the LHC and progressing as planned, the injector complex is gradually being restarted. A week ago, Linac4, the PS Booster (PSB), the PS and their transfer lines were closed again.

Before powering the equipment or even considering injecting a beam, the operations team carries out mandatory patrols to ensure that no one is present in the tunnels. Closing the machine means that the access control and safety systems are fully operational, preventing any unauthorised entry when the beam is active and ensuring that no beam can be injected when access is granted.

As mentioned in my first report of 2025, the final step in this process is the DSO tests, which are designed to confirm that the system is functioning as it should. These tests were successfully completed on 10 February for Linac4, the PSB, the PS and their transfer lines. With this milestone achieved, everything is now in place for the restart of the machines.

The Linac4 source was restarted over a week ago. It is currently pulsing every 1.2 seconds, producing a beam current of 40 mA. Until 19 February, the extracted particles will be absorbed by a beam dump located just downstream of the source. This allows measurements of the beam current to be taken while preventing further acceleration within Linac4.

During this period, the operations team, together with equipment experts, is gradually bringing all of Linac4’s subsystems back online, including the RF accelerating structures, the magnet systems and the beam diagnostic systems, in preparation for injecting and accelerating the beam. This will ensure that the beam is ready to be received by the PSB for commissioning on 27 February.

By that date, the PSB’s subsystems will also have been fully restarted and will be operational. The PSB is then expected to provide its first beams for the PS beam commissioning, which is scheduled to begin on 5 March.

Some of you may recall that, in previous years, the Linac4 source provided a beam current of 35 mA for all operational beams. This year, following successful tests at up to 45 mA, we have decided to start and operate with a beam current of 40 mA.

The total number of protons injected into the PSB is determined by the combination of the Linac4 beam current and the duration of its pulse. By increasing the beam current by 15%, the pulse length and thus the duration of injection into the PSB, can be reduced by the same percentage. While this adjustment is not strictly necessary for any of the currently required operational beams, gaining experience with this mode of operation could be valuable for future beam configurations and help to improve performance.

Of course, our primary objective is still the delivery of stable, high-quality beams to all the experiments. If we observe any degradation of beam performance due to this change, the Linac4 beam current can be readjusted to 35 mA. With a few hours of fine-tuning, all beams could then be restored to the exact same conditions as last year. If that is the case, it will be essential to study and understand the cause of any performance variations. However, at this stage, there is no indication that the change of the Linac4 source current will negatively impact the beam delivery to the experiments.

The Chamonix Workshop 2025, held from 27 to 30 January, brought together CERN’s accelerator and experimental communities to reflect on achievements, address challenges and chart a course for the future.

As the discussions made clear, CERN is at a pivotal moment. The past decade has seen transformative developments across the accelerator complex, while the present holds significant potential and opportunity.

Reviewing accelerator operations

The workshop opened with a review of accelerator operations, supported by input from December’s Joint Accelerator Performance Workshop. Maintaining current performance levels requires an extraordinary effort across all the facilities. Performance data from the ongoing Run 3 shows steady improvements in availability and beam delivery. These results are driven by dedicated efforts from system experts, operations teams and accelerator physicists, all working to ensure excellent performance and high availability across the complex.

Attention is now turning to Run 4 and the High-Luminosity LHC (HL-LHC) era. Several challenges have been identified, including the demand for high-intensity beams, electron cloud effects and radiofrequency (RF) power limitations. Measures to address these issues will be implemented during Long Shutdown 3 (LS3), ensuring CERN’s accelerators continue to meet the demands of its diverse physics community.

Preparing for Long Shutdown 3 and the High-Luminosity LHC

LS3 will be a crucial period for CERN. In addition to the deployment of the HL-LHC and major upgrades to the ATLAS and CMS experiments, it will see a widespread programme of consolidation, maintenance and improvements across the accelerator complex to secure future exploitation over the coming decades.

Progress on the HL-LHC upgrade was reviewed in detail, with a focus on key systems – magnets, cryogenics and beam instrumentation – and on the construction of critical components such as crab cavities. The next two years will be decisive, with significant system testing scheduled to ensure these technologies meet ambitious performance targets.

Planning for LS3 is already well advanced. Coordination between all stakeholders has been key to aligning complex interdependencies, and the experienced teams are making strong progress in shaping a resource-loaded plan. The scale of LS3 will require meticulous coordination, but it also represents a unique opportunity to build a more robust and adaptable accelerator complex for the future.

A diverse and evolving physics programme

Looking beyond LS3, CERN’s unique accelerator complex is well positioned to support an increasingly diverse physics programme. This diversity is one of CERN’s greatest strengths, offering complementary opportunities across a wide range of fields.

The high demand for beam time at ISOLDE, n_TOF, AD-ELENA and the North and East Areas underscores the need for a well-balanced approach that supports a broad range of physics. The discussions highlighted the importance of balancing these demands while ensuring that the full potential of the accelerator complex is realised.

Future opportunities such as those highlighted by the Physics Beyond Colliders study will be shaped by discussions being held as part of the update of the European Strategy for Particle Physics (ESPP). Defining the next generation of physics programmes entails striking a careful balance between continuity and innovation, and the accelerator community will play a central role in setting the priorities.

The Future Circular Collider and long-term vision

A forward-looking session at the workshop focused on the Future Circular Collider (FCC) Feasibility Study and the next steps. The physics case was presented alongside updates on territorial implementation and civil engineering investigations and plans. How the FCC-ee injector complex would fit into the broader strategic picture was examined in detail, along with the goals and deliverables of the pre-technical design report (pre-TDR) phase that is planned to follow the Feasibility Study’s conclusion.

While the FCC remains a central focus, other future projects were also discussed in the context of the ESPP update. These include mature linear collider proposals, the potential of a muon collider and plasma wakefield acceleration. Development of key technologies, such as high-field magnets and superconducting RF systems, will underpin the realisation of future accelerator-based facilities.

Looking to the future

The next steps – preparing for Run 4, implementing the LS3 upgrade programmes and laying the groundwork for future projects – are ambitious but essential. CERN’s future will be shaped by how well we seize these opportunities.

The shared expertise and dedication of CERN’s personnel, combined with a clear strategic vision, provide a solid foundation for success. The path ahead is challenging, but with careful planning, collaboration and innovation, CERN’s accelerator complex will remain at the heart of discovery for decades to come.

CERN is committed to maintaining a secure environment for its personnel, site and assets. In line with this commitment, the Director-General has adopted the CERN Security Policy in order to set out the framework for the physical protection of CERN personnel and any other contributors on the CERN site, of the CERN site itself and of the property and assets in the Organization’s custody.

The Security Policy aims to prevent, avoid or mitigate risks against the Organization while preserving the campus spirit.

CERN contributors are expected to familiarise themselves with this Policy and with their responsibility to contribute to a secure working environment. A dedicated online course “Security Awareness / Sensibilisation à la sûreté” is available on the CERN Learning Hub.

To support the implementation of this Policy, the Director-General appointed a Security Committee in October 2024. This Committee has been established to advise the Director-General on security matters, to recommend updates to the Security Policy and measures and to monitor its implementation. It consists of the Head of the department in charge of security (SCE) acting as Chair, the Head of the Security Service, and one representative from each of the following: the Human Resources department, the Legal Service, the Occupational Health and Safety and Environmental Protection unit, and the Host State Relations service.

We appreciate your cooperation in fostering a secure and protected environment at CERN. For further information, please contact the Security service.

Registration is now open for the Open Symposium of the 2026 Update of the European Strategy for Particle Physics.

The symposium is a major step of the process to involve the full community in discussing inputs submitted by 31 March. The ongoing strategy update will guide the direction of the field for the forthcoming years.

The Open Symposium will take place in Venice Lido, Italy, on 23–27 June 2025. Early attendance fees are available until 13 April and reductions are available for students. The registration period closes on 13 June.

All organisational details, including travel and accommodation can be found at: https://agenda.infn.it/event/44943/overview and the scientific programme is available at https://agenda.infn.it/event/44943/program.

During the period from 16 June to 5  September 2025 inclusive, there will be a limited number of jobs for summer work at CERN (normally unskilled work of routine nature), which will be made available to children of members of the personnel (i.e. anyone holding an employment or association contract with the Organization). Candidates must be aged between 18 and 24 inclusive on the first day of the contract and must have insurance covering illness.

Candidates must already hold a residence permit granted by one of CERN's host states (France or Switzerland) at the time of their application and must have a valid residence permit. Proof will be required.

The duration of all contracts will be 4 consecutive weeks and the allowance will be CHF 1587 for this period. Candidates should apply via HR department’s electronic recruitment system, SmartRecruiters: https://smrtr.io/pvMNv          

Completed application forms must be returned by 16 March 2025 at the latest. To allow as many people as possible to benefit, each child may participate in this programme only once.

The results of the selection will be available mid of May 2025.

If you have any questions, please contact us here.

Virginie Galvin
HR department

Note that only authorised private parties can take place in Restaurant no.1. The authorisation has to be sought, at least 48 hours in advance, through CERN Service Portal: Authorisation request to organise a drink in the Restaurant 1 extension.

The terms and conditions are the following:

• Operational Circular No.08 Dealing with alcohol-related problems shall be observed.
• Private events shall not disturb activities of the Organization in any respect. Any noisy disturbance has to be avoided after 22:00.
• The party organiser bears the responsibility for the event and for security reasons, shall be on site for the duration of the event.
• All participants have to observe CERN Code of Conduct in every respect.
• The party shall be stopped at the latest at 23:30 (except for Saturdays and Sundays 21:30)
• The furniture (tables, chairs, etc.) shall not be moved; any damages shall be borne by the organiser
• Immediately after the event, the cutlery, plates and glasses shall be cleared and put back at the right place. The tables and the place in general shall be cleaned properly. The waste shall be put in the appropriate bins. Glass bottles shall be removed, no glass recycling being available at the restaurants. Any additional cleaning to be provided by the restaurant staff will be charged to the organiser.

The Standard Model of particle physics is based on the idea that if you simultaneously swap a matter particle for its antimatter version (changing the sign of its charge), flip its spatial coordinates as if viewed through a mirror (parity) and reverse the direction of time, then there should be no difference in the behaviour of the two particles. Due to the central role of fundamental symmetry in quantum field theory, discovering even a small violation of this principle, known as charge-parity-time (CPT) symmetry, would suggest that our understanding is incomplete and could point to new physics beyond the Standard Model.

Experiments at CERN’s Antimatter Factory test fundamental principles such as CPT symmetry by studying the properties and behaviour of antimatter and comparing them with normal matter. The ALPHA experiment performs such tests through spectroscopy of antihydrogen – that is, by measuring the frequencies of transitions in the anti-atom using laser light or microwaves. If the results match those of normal hydrogen, the measurement is consistent with CPT symmetry. These frequencies, measured in units of Hz, equivalent to one per second, correspond to the energy level intervals in atoms and the spectral lines that arise when they make quantum transitions between levels. To accurately compare matter and antimatter, the frequencies must be determined incredibly precisely, requiring ultra-precise clocks. That’s why a caesium fountain clock was recently installed in ALPHA and a new optical fibre link between the experiment and the French National Metrological Institute in Paris is now online. Both the clock and the optical link will help improve the precision of ALPHA’s antihydrogen measurements by orders of magnitude.

“For our previous measurement of the transition between the ground state and the first excited state of antihydrogen, we used a simpler clock made out of a quartz oscillator referenced via GPS satellite as a frequency reference, and we reached a precision on the transition frequency of two parts per trillion (2×10^-12),” says physicist Janko Nauta from the ALPHA collaboration. “However, the equivalent measurement on hydrogen, performed a few years before our antihydrogen measurement, has an even higher precision, of four parts per quadrillion (4×10^-15), calling for a better clock to look for potential differences between matter and antimatter.”

“For ALPHA, both the optical fibre link and the caesium fountain clock play important roles in making antihydrogen measurements with a precision that matches that of the hydrogen measurements,” continues Nauta. “While we rely on the clock, the link helps us to reduce noise in the measurement and to better evaluate the clock in the long term, to verify that it stays accurate. In addition, the link will make it possible to use signals from optical quantum clocks in the future, surpassing the stability of clocks that currently realise the SI second.”

The link is part of the REFIMEVE+ network, a project that distributes an ultra-stable optical frequency reference to research laboratories across France and beyond via existing optical cables on the French internet network. It is a pilot implementation of a new project that aims to connect multiple experiments at CERN to REFIMEVE+. This has the potential to improve the precision of clocks across CERN and could provide a new way for the Laboratory to access Coordinated Universal Time (UTC) – the global standard for timekeeping. The optical signal from the link can synchronise with UTC more precisely than via GPS satellite, which is currently used across CERN.

“The CERN Quantum Technology Initiative envisages having more precise frequency signals delivered to CERN from other national metrology institutes and distributing them to all the interested experiments at the Laboratory,” says Edoardo Martelli from CERN’s IT department. “Having more sources allows a more precise synchronisation of the local clocks and increases the robustness of the service.”

ALPHA’s most recent precise measurement of the transition between the ground state and the first excited state of antihydrogen has placed tighter constraints on violations of CPT symmetry than its previous measurement. With the new optical link, the collaboration hopes to put CPT symmetry to even more stringent tests.