Bike to Work is back at CERN, encouraging everyone to leave their car behind and enjoy the benefits of active travel. Choose a healthier and more environmentally friendly way to commute during May and June, or continue biking if you are already regularly in the saddle.

To take part, form a team of four colleagues - one of whom can participate as a pedestrian - and take on the challenge together. The goal is simple: commute by bike (or on foot) regularly, at least one day out of every two during the period of the campaign. It’s not about the number of kilometres you cover but about helping to build consistent, sustainable habits.

Whether you’re a seasoned cyclist or just getting started, every active commute contributes to your well-being, strengthens your connection with your colleagues and helps to reduce your impact on the environment.

Sign up on the Bike to Work website, where you can also apply to join an incomplete team. Ready to get moving?

A big thank you to all of you who sent in your photos for our photo competition on the theme ‘Spring at CERN’. We really enjoyed looking through them and it wasn’t easy to choose the winner. They are now available in a CC-BY photo collection, shown as a slideshow here:

Congratulations to Aneta Sabanovic from the IPT department, who wins the Chocopass kindly offered by the CAGI cultural kiosk at CERN and Geneva Tourism. The pass gives her the chance to explore Geneva for a day and taste chocolate from a range of chocolate shops.

We’d like to thank the International Geneva Welcome Centre (CAGI) and Geneva Tourism for offering a Chocopass to the winner! The CAGI cultural kiosk is located in CERN’s main building and is open from Monday to Friday from 8:30 a.m. to 1:30 p.m. It offers numerous discounts for local activities and events both in Switzerland and in France – Find out more about CAGI on their website.

Ethics is essential, in particular in our workplace. It contributes to a positive and productive work environment while also fostering trust among us, as CERN contributors, as well as the trust of our stakeholders, such as Member States, contractors and research institutions.

At CERN, our ethics-related framework is designed to guide us to act in accordance with the Organization’s values and with the conduct that is expected of us, and to establish and maintain a respectful working environment. It is up to each and every one of us to respect it.

To ensure that everyone is aware of the guidelines of our ethical framework, the HR Department has developed an e-learning course entitled “Ethics at CERN”, which is available in English and French on the CERN Learning Hub. As of now, this course is mandatory for all members of the CERN personnel.

To make our ethics-related framework more easily accessible, all the relevant information and resources can be found here: https://hr.web.cern.ch/ethics. If you have any ethics-related questions, please contact info-codeofconduct@cern.ch.

To go further, take the new e-course “Managing Conflict of Interest”

This online course introduces CERN’s policy on conflicts of interest and explains why identifying and managing such situations is essential for maintaining trust, integrity and fairness in the workplace.

The course addresses the following topics:

• What a conflict of interest is and why it matters
• The difference between actual and perceived conflicts of interest
• Examples of common conflict situations
• CERN’s policy on and official definition of conflicts of interest, including the rules on gifts, favours and hospitality
• Your responsibilities
• Where to find further guidance and support

The module also includes case studies to help you to recognise and respond to conflicts of interest in practice. Register now on the CERN Learning Hub.

On Saturday, 25 April 2026, marking the International Girls in ICT Day, the CERN Science Gateway will be opening its doors to girls aged 12 to 16 for a morning and afternoon dedicated to exploring the digital world.

This global event encourages girls to explore the many opportunities offered by information and communication technologies. 

Discover how artificial intelligence systems like ChatGPT work!  Or how a computer recognises images, sounds and even music. With scientists from CERN, you’ll learn how to train your own AI system and understand its strengths…and its limitations.

What if you created your own smart wristband?  In this workshop, you’ll train a model capable of recognising your movements (walking, jumping, clapping). It’s an amusing way to understand how AI can apply to real life!

Sign up and find out more, and check out the many activities being organised at the CERN Science Gateway throughout the day.

Don’t miss the next lunch & learn conference organised by the CERN Medical Service on the theme of “A healthy mind for a calmer future”. This latest session will be held in the Dirac Room (40/S2-D01) from 11.30 a.m. to 1.30 p.m. on 22 April and will focus on the topic of “Mind-Body connection: science, experience and resilience”. It will feature a talk by Dr Benzakhour from the Geneva University Hospitals (HUG) and a personal account by our colleague Julien Fernandez from the EN Department, who will share his journey on “Learning to live differently’.

Spaces are limited, so register now!

The event will also be webcast and recorded.

14 Apr 10:00 | Physics | Salle Dirac & Online | QTI Seminars | EN
Atom interferometry : from practical quantum sensing to fundamental physics searches

14 Apr 11:00 | Physics | Main Auditorium & Online | LHC Seminars | EN
Study of top quark pair production at the threshold using CMS data

14 Apr 14:00 | Physics | TH Conference Room & Online | String Theory Seminars | EN
Taxonomy of branes in infinite-distance limits

15 Apr 12:00 | Knowledge Transfer | IdeaSquare | IdeaSquare Workshops & Events | EN
Prototyping at CERN

16 Apr 17:00 | Knowledge Transfer | Online | CERN Alumni | EN
R1 Talk: Responsible AI: Lessons from Building WORB

16 Apr 17:00 | Knowledge Transfer | 774/R-013 | CERN Venture Connect | EN
Scientist to Founder: From Research to Venture Creation

17 Apr 17:00 | At CERN | CERN Alumni | EN
Soon-to-be alumni networking event (for contracts coming to an end between April and June)
Email alumni.relations@cern.ch to register

17–18 Apr 10:00 | At CERN | Meyrin Centre, Geneva | World Liver Day | EN
Free liver scanning

23 Apr 10:00 | At CERN | CERN Science Gateway Auditorium & Online | Director General | EN & FR
Town Hall

24 Apr 16:00 | Accelerators | BE Auditorium Meyrin & Online | BE Seminars | EN
Performance limitations due to beam-beam interactions and wakefields in high energy lepton colliders

25 Apr 08:30 | Knowledge Transfer | CERN | Public Events | FR
Girls in ICT 2026 – Découverte de l'informatique au CERN

28 Apr 17:30 | At CERN | Main Auditorium | Staff Association | EN
Steer Your Own Path: Resilience and mindset lessons from a 46,000 km bicycle journey around the world

28 Apr 18:30 | At CERN | IdeaSquare | IdeaSquare Workshops & Events | EN
HOPE Networking Event

29 Apr 20:00 | At CERN | CERN Science Gateway | Public Events | EN & FR
Hunting the Higgs

4–8 May | Knowledge Transfer | TH Conference Room & Online | TH Workshops | EN
Gravitational waves from amplitudes

7 May 12:15 | At CERN | CERN | Staff Association | EN & FR
54th CERN Relay Race

8 May 10:00 | At CERN | Library | Archives, Library & Open Science Events | EN
Meet the author of "A concise history of radiation detectors: Hunting for the unknown"

13 May 16:00 | At CERN | Library | Archives, Library & Open Science Events | EN
Meet the author of "STARBORN: How the stars made us - and who we would be without them"

Save the date: 18 July | At CERN | CERN | Staff Association | EN & FR
CERN Hardronic Music Festival 2026

4–8 May | Computing | CERN | SC4RC | EN
Sustainability Conference for Responsible Research Computing

5 May–24 Nov | Knowledge Transfer | CERN | Knowledge Transfer | EN
CERN Entrepreneurship Academy 2026

20 May | Knowledge Transfer | Lausanne | FameLab | EN
FameLab Switzerland Lausanne Heat

22 May 14:00 | At CERN | Online | Micro-Talks | EN
Thriving with Confidence: Moving Past Imposter Syndrome

25–29 May | Computing | Chulalongkorn University | CHEP | EN
28th Conference on Computing in High Energy and Nuclear Physics (CHEP 2026)

8–12 Jun | Knowledge Sharing | CERN | CERN IdeaSquare | EN
CERN IdeaSquare Journal of Experimental Innovation Summer School

15–26 Jun | Accelerators | Jūrmala, Latvia | CERN Accelerator Schools | EN
CAS course on Medical Accelerators

19 Jun–2 Jul | Physics | Ostróda, Poland | CERN Schools | EN
European School of High-Energy Physics

22 Jun–28 Aug | Experiments | CERN | CERN NextGen Triggers | EN
CERN STEAM Academy

1–10 Jul | Physics | Bucharest, Romania | CERN Schools | EN
16th International School of Trigger and Data Acquisition (ISOTDAQ 2026)

14 Sep–18 Sep | Engineering | Rio de Janeiro | RPC Conference | EN
XVIII Conference on Resistive Plate Chambers and Related Detectors

20 Sep–3 Oct | Accelerators | Peebles, Scotland | CERN Accelerator Schools | EN
Introduction to Accelerator Physics

22 Sep–1 Oct | Knowledge Transfer | Sarajevo, Bosnia and Herzegovina | I.FAST | EN
I.FAST 2026 Challenge

14–27 Oct | Physics | Taouyuan, Taiwan | CERN Schools | EN
2026 Asia Europe Pacific School of High-Energy 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

In order to help members of the personnel who may need assistance, the Organization has decided to set up individual tax consultation sessions with the French tax authorities (Service des Impôts des Particuliers (SIP) de Valserhône) to answer questions on income tax matters in France. 

These consultations will take place on the Meyrin site, on Friday 17 April 2026 and will be run by ten representatives of the SIP. The sessions will require pre-booking an appointment via this portal.

There are a limited number of time slots available, so we recommend you sign up early.

Please note that these meetings will be in French. Should you need any assistance with the language, we advise you to ask a French-speaking colleague for help.

For any questions regarding these meetings, please contact  SIPTax.support@cern.ch.

As nature awakens and we embrace the joys of spring, it’s important to remember that ticks are also becoming active. These tiny parasites can pose serious health risks by transmitting infections such as Lyme disease (Lyme borreliosis) and tick-borne encephalitis (TBE). While Lyme disease is treatable with antibiotics, TBE is rarer, with up to 12 000 cases reported globally each year, but can be prevented with vaccination. The TBE vaccine is recommended for anyone, including children, living in or travelling to high-risk areas. In Europe, these areas include Switzerland, Austria, Czech Republic, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Slovakia, Slovenia and Sweden.

If you find a tick on your body, visit the CERN Medical Service infirmary for safe removal and expert advice.

For more information on ticks, tick-borne diseases, vaccination options and prevention tips, visit the dedicated Medical Service webpage: hse.cern/ticks.

CERN’s vast site hosts a variety of buildings and installations, as well as diverse groups of people, from seasoned personnel to first-time visitors. Fire safety measures are implemented to protect this diverse population, but also CERN’s costly infrastructure and the environment. Ensuring safe evacuation is a priority in this context, with building layouts designed to facilitate quick, orderly exits. But even the best infrastructure relies on effective human response.

A recent planned evacuation of most of the Main Building complex (R1 and Buildings 500, 503, 61, 62, 63 and 64, but not 60) offered valuable insights in this respect. At 2.07 p.m. on a cold and cloudy afternoon, sirens blared. While the sirens were loud and clear and the fire doors and lifts responded as designed, human behaviour varied. Many of the approximately 220 people who were present evacuated to the assembly point. However, half of them hesitated before starting to move, some left the building but stayed near the exits, eight re-entered the building and ten entered during the alarm. Two of the emergency exits in the Main Building complex were obstructed by equipment. Thanks to individuals taking the lead, notably restaurant staff, who acted as emergency guides, the evacuation finally got under way. The event highlighted the importance of keeping exits clear and of being familiar with procedures, as well as the power of leading by example in emergencies.

We all play a role in ensuring that CERN is a fire-safe place: make sure that you know and understand the applicable evacuation procedures and that you are aware of the nearest emergency exits and assembly points, and communicate this information to newcomers and visitors. Further, CERN regularly organises planned evacuations like the one mentioned above. They prepare us all for real emergencies: treating every drill as if it were real can make the difference between confusion and calm in a crisis.

If you see blocked exits or unsafe practices, speak up and inform your TSO or DSO. To find out more about fire safety in general, consult the dedicated Fire Safety Risks webpages. If you have specific queries about fire safety, reach out to the Fire Safety Engineering team: hse-fset@cern.ch.

Safety first. Safety always.

16–27 Mar | At CERN | Main Building | CERN Staff Association | EN & FR
Nuits blanches exhibition

25 Mar 14:00 | Physics | TH Conference Room & Online | Theory Colloquia | EN
Cosmic structure formation

26 Mar 16:00 | Knowledge Transfer | Online | CERN Alumni | EN
HOPE Networking Event

26 Mar 16:00 | At CERN | IdeaSquare | IdeaSquare Workshops & Events | EN
Review of Medical Physics in Africa

27 Mar 11:00 | Experiments | 222/R-001 & Online | Detector Seminars | EN
A new dimension for ATLAS: The High Granularity Timing Detector

30 Mar–10 Apr | At CERN | Main Building | CERN Staff Association | EN & FR
The Quantum Botijo

31 Mar 14:00 | Physics | TH Conference Room | String Theory Seminars | EN
Polar states in AdS3 holography

31 Mar 20:00 | At CERN | CERN Science Gateway | Public Events | EN
Rising Stars

1 Apr 11:00 | At CERN | Library | Archives, Library & Open Science Events | EN
Meet the author of "Space Times Matter: One Hundred Short Stories About the Universe"

9 Apr 10:00 | Physics | Salle Bohr | QTI Seminars | EN
Formalism for simulating lattice gauge theories coupled to matter on a quantum computer

15 Apr 12:00 | Knowledge Transfer | IdeaSquare | IdeaSquare Workshops & Events | EN
Prototyping at CERN

23 Apr 10:00 | At CERN | CERN Science Gateway Auditorium & Online | Director General | EN & FR
Town Hall

29 Apr 20:00 | At CERN | CERN Science Gateway | Public Events | EN & FR
Hunting the Higgs

7 May 12:15 | At CERN | CERN | Staff Association | EN & FR
54th CERN Relay Race

13 May 16:00 | At CERN | Library | Archives, Library & Open Science Events | EN & FR
Meet the author of "STARBORN: How the stars made us - and who we would be without them"

Save the date: 18 July | At CERN | CERN | Staff Association | EN & FR
CERN Hardronic Music Festival 2026

5 May–24 Nov | Knowledge Transfer | CERN | Knowledge Transfer | EN
CERN Entrepreneurship Academy 2026

4–8 May | Computing | CERN | SC4RC | EN
Sustainability Conference for Responsible Research Computing

20 May | Knowledge Transfer | Lausanne | FameLab | EN
FameLab Switzerland Lausanne Heat

25–29 May | Computing | Chulalongkorn University | CHEP | EN
28th Conference on Computing in High Energy and Nuclear Physics (CHEP 2026)

8–12 Jun | Knowledge Sharing | CERN | CERN IdeaSquare | EN
CERN IdeaSquare Journal of Experimental Innovation Summer School

15–26 Jun | Accelerators | Jūrmala, Latvia | CERN Accelerator Schools | EN
CAS course on Medical Accelerators

19 Jun–2 Jul | Physics | Ostróda, Poland | CERN Schools | EN
European School of High-Energy Physics

22 Jun–28 Aug | Experiments | CERN | CERN NextGen Triggers | EN
CERN STEAM Academy

1–10 Jul | Physics | Bucharest, Romania | CERN Schools | EN
16th International School of Trigger and Data Acquisition (ISOTDAQ 2026)

20 Sep–3 Oct | Accelerators | Peebles, Scotland | CERN Accelerator Schools | EN
Introduction to Accelerator Physics

22 Sep–1 Oct | Knowledge Transfer | Sarajevo, Bosnia and Herzegovina | I.FAST | EN
I.FAST 2026 Challenge

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

The CERN Relay Race, organised by the Running Club and the Staff Association, will be back on Thursday, 7 May for its 54th edition.

This now legendary race – the first edition took place in 1971 – returns with the same ingredients as in past years, which led to record numbers of participants in 2025: 183 teams and over 1100 runners/walkers in total. The goal of the 2026 edition is thus clear: to beat that record!

The main race will start at 12.15 p.m. in front of Building 40, closely followed by the walkers’ race and the children’s race, which is being organised with the support of the Jardin des Particules.

The CERN Alumni Network will be taking part in the event thanks to an online relay race challenge: teams composed of CERN alumni from across the globe will be able to run the CERN Relay Race distances in their different locations.

The social part of the event won’t be forgotten, with the participation of various CERN clubs and Staff Association partners that will be presenting their activities, and there will be a professional DJ to liven up the event. As always, runners are more than welcome to participate in fancy dress and to compete in the costume contest.

No doubt the spectators will be out in force cheering all the teams on and the sun will shine, making the 54th edition the best one yet.

Register on the CERN Running Club webpage.

Due to civil engineering works, the Meyrin inter-site tunnel will be exceptionally closed to traffic from Monday 30 March to Thursday 2 April inclusive.

Thanks for your understanding.