Press release Nuclei & Particles CNRS 1st september 2025

The gigantic JUNO detector, currently under construction in China with the participation of IN2P3, will soon be bugging the elusive and mysterious elementary particles that are neutrinos. Its objective: to penetrate the secrets of the discrete waltz interpreted by these ghostly grains of matter, which scientists call oscillations and which so intrigue them. With a year to go before the start of the experiment, we take a look at the images from 700 m underground in the heart of the giant under construction.

More information:

Press release: https://www.in2p3.cnrs.fr/en/cnrsinfo/juno-giant-listen-discrete-waltz-neutrinos

CPPM Contact:

José Busto, teacher-researcher at Aix-Marseille University, researcher on the JUNO project, in the neutrino astroparticule team

CNRS Nuclei & Particles press release, 31 july 2025

Higgs boson self-coupling is a phenomenon whereby the Higgs interacts with itself and which can manifest itself in particle collisions at the LHC at CERN, through the production of pairs of Higgs bosons. This self-coupling is of great interest to physicists because it could provide an unprecedentedly sensitive probe for searching for the influence of as yet unknown particles. Thanks to the development of machine learning techniques and the increasingly efficient accumulation of collision data by the ATLAS and CMS particle detectors, its measurement, considered impossible just a few years ago, now seems to be taking shape.

More information:

Press release (only in french): https://www.in2p3.cnrs.fr/fr/cnrsinfo/letau-se-resserre-sur-la-valeur-de-lauto-couplage-du-boson-de-higgs

Contact at CPPM:

Arnaud Duperrin, ATLAS Team Leader

amU Offer: amU Junior Professor Chair Exploring the Cataclysmic Universe

Aix-Marseille University (amU) intends to recruit a candidate whose scientific excellence and dynamism will enable her/him to address the major questions in astrophysics, astroparticle physics and particle physics through the use of large instruments, focused on the exploration of the cataclysmic Universe by performing multi-messenger astronomy of the violent and transient sky sources. This MULTIVERSE project benefits from close interdisciplinary collaborations between observation with high-energy neutrino detectors and multi-wavelength experiments of violent cosmic phenomena by teams of the CPPM and LAM laboratories, and CPT’s expertise in cosmology and astroparticles.

The selected candidate will play a leading role in these multi-messenger studies of the violent and transient Universe, in particular by exploiting data derived from the KM3NeT underwater neutrino telescope, the SVOM satellite, and/or the COLIBRI robotic telescope (optimised for the detection of Gamma Ray Bursts). Involvement in detector construction is a requirement.

This tenure-track position (known as “CPJ” in the French academic system) includes start-up funds of €200k, which the appointee can use to establish her/his research program and recruit PhD students and postdocs. In addition, this project is strongly supported by CNRS Nucléaire & Particules (IN2P3) through additional funding, in the event of recruitment at CPPM, of a PhD, a postdoc, and operating costs. The CPJ position is a fixed-term contract (CDD) lasting 4 years, during which the researcher will not only conduct research but also have a light teaching load or service responsibilities. At the end of this 4-year period, a tenure-review committee will evaluate the researcher's performance and recommend whether he/he should be granted tenure as an amU Full professor.

The recruited person will perform her/his teaching activities at Aix-Marseille University, for instance within the Physics Department of the Faculty of Science. As such, he/she must be able to teach courses both at the undergraduate and graduate levels (BS/MS).

Importantly, any interested candidate should register via the ODYSSEE website of the Ministry of Higher Education and Research by creating a personal account at: https://odyssee.enseignementsup-recherche.gouv.fr/ where the full position profile and the candidateship form can be found.

Deadline for submitting application: September 1st 2025, 4h PM (Paris time)

For further questions, please contact at CPPM: Vincent Bertin

Further informations:

• CPJ or Chaires de Professeur Junior: https://www.enseignementsup-recherche.gouv.fr/fr/des-carrieres-plus-attractives-les-chaires-de-professeur-junior-46095

• KM3NeT at CPPM: https://www.cppm.in2p3.fr/transfert/KM3NeT/CPJ/HE_neutrino_astronomy_with_KM3NeT_at_CPPM.pdf

• KM3NeT on CPPM Web Site: https://www.cppm.in2p3.fr/web/en/research/astroparticles/index.html#Neutrinos

Some significant photos: https://phototheque.in2p3.fr/index.php?/category/1440

CNRS Offer: CPJ-2025-028. CNRS Junior Professor Chair Understanding the extreme Universe with CTAO

The French National Centre for Scientific Research (CNRS) is offering a tenure-track position focused on the Cherenkov Telescope Array Observatory (CTAO) at one of the following French laboratories: CPPM (Marseille), IRAP (Toulouse), or either LLR or LUX (both in the Paris region).

The selected candidate will lead a program on the theme "Understanding the Extreme Universe with CTAO," capitalizing on the capabilities of CTAO to explore the non-thermal Universe. This research should align with the Key Science Projects outlined in Science with CTA and may include participation in the commissioning, validation, and calibration of the telescopes, the development and commissioning of the associated computing infrastructure, as well as the exploitation of CTAO during the initial science phase.

This tenure-track position (known as “CPJ” in the French academic system) includes start-up funds of €200k, which the appointee can use to establish their research program. The position begins as a fixed-term contract (CDD) lasting between 3 and 6 years, during which the researcher will have a light teaching load or service responsibilities in addition to conducting research. At the end of this period, a tenure-review committee will evaluate the researcher's performance and recommend whether they should be granted tenure as a CNRS research director (DR).

Those who are interested should apply through the following link: https://emploi.cnrs.fr/Offres/CPJ/CPJ-2025-028/Default.aspx?lang=EN

The deadline for this application is July 14th, 2025.

For further questions, please contact:

• Cristinel Diaconu for CPPM, Marseille

• Pierre Jean for IRAP, Toulouse

• Steve Fegan for LLR, Palaiseau

• Andreas Zech for LUX, Meudon

The candidates should arrange for their letters of recommendation to be sent directly to the president of the recruitment committee. Contact: Nicolas Leroy, IN2P3 Deputy Scientific Director "Astroparticles and Cosmology"

For CPPM the service responsibility will consist in service work for CTAO.

Further informations:

• CTAO at CPPM: https://www.cppm.in2p3.fr/transfert/CTAO/CTAO-group-CPPM.pdf

• CTAO on CPPM Web Site: https://www.cppm.in2p3.fr/web/en/research/astroparticles/index.html#Photons

Some significant photos: https://phototheque.in2p3.fr/index.php?/category/1441

The ATLAS experiment has set a new limit on the production of a pair of Higgs bosons (HH) decaying into a pair of b quarks and a pair of photons with data collected in 2022, 2023, and 2024, combined with data from Run 2. This is the first result from ATLAS with a record integrated luminosity of 308 fb-1. The upper limit observed on the cross section is 3.8 times that of the Standard Model with a confidence level of 95%. The ratio of the calculated cross section to the predicted cross section is measured to be 0.9+1.4-1.1, in full agreement with the Standard Model. This is an important result for ATLAS, paving the way for tighter constraints on Higgs self-coupling with Run 3 data. The results were presented at the Higgs Pairs Workshop, May 11-17, 2025.

The ATLAS group at CPPM contributed significantly to this analysis by participating in the development of the analysis code, data production, validation of di-Higgs reconstruction techniques, and statistical analysis. The group also contributed to the preparation of photon identification efficiency corrections, which are essential for this analysis.

This result is an important achievement for the ATLAS CPPM group after a long-standing contribution to the main elements of this analysis. The CPPM led the upgrade of the electronics of the liquid argon calorimeter trigger system with significant improvements to the photon triggers used in this analysis. In addition, the group's contribution to b-jet identification with increasingly powerful algorithms based on state-of-the-art machine learning techniques has had a significant impact on improving the selection efficiency of the rare HH->bbγγ signal.

More information : ATLAS public web site

CPPM contact: Georges Aad, CNRS researcher CNRS in the ATLAS team

CERN press release, 7 april 2025

The Breakthrough Prize in Fundamental Physics was awarded to the ALICE, ATLAS, CMS and LHCb collaborations during a ceremony held in Los Angeles on 5 April. This weekend, the ALICE, ATLAS, CMS and LHCb collaborations at the Large Hadron Collider at CERN were honoured with the Breakthrough Prize in Fundamental Physics by the Breakthrough Prize Foundation. The prize is awarded to the four collaborations, which unite thousands of researchers from more than 70 countries, and concerns the papers authored based on LHC Run-2 data up to July 2024. It was received by the spokespersons who led the collaborations during that time.

More information :

Press release: https://home.cern/news/press-release/knowledge-sharing/lhc-experiment-collaborations-cern-receive-breakthrough-prize

CPPM Contacts:

Arnaud Duperrin, CNRS researcher, lead of ATLAS team

Olivier Leroy, CNRS researcher, lead of LHCb team

Press release, 31 march 2025

In 2020, the CERN Council requested a feasibility study for a future circular collider at CERN (FCC).

Published on March 31, the report on the project's feasibility study will serve as a contribution to the European strategy for particle physics and will be evaluated by the CERN Council in the coming months.

The report also summarizes the developments made in recent years in preparation for this project, both in terms of the measurements and research planned at the FCC, and in terms of the accelerators, civil engineering studies, and efforts to develop environmentally friendly equipment.

More information:

Press release: https://home.cern/news/news/accelerators/cern-releases-report-feasibility-possible-future-circular-collider

Contact at CPPM :

Cristinel Diaconu, director of CPPM

Nuclei & Particles CNRS press release, 31 march 2025

The decay of the Λb0 (lambda b) baryon, a particle composed of three quarks, like protons and neutrons, produces new particles of matter and antimatter (equivalent to a particle of matter but with the opposite sign) in slightly different proportions, whereas one would have expected perfect equality. This discrepancy, measured by the LHCb experiment at CERN, is the first of its kind observed in baryons, particles containing three quarks. It could help explain why antimatter seems to be virtually absent from our Universe.

More information:

Press release (only in french): https://www.in2p3.cnrs.fr/fr/cnrsinfo/la-collaboration-lhcb-observe-une-asymetrie-chez-une-particule-trois-quarks

Contact at CPPM :

Olivier Leroy, CNRS researcher, lead of LHCb team

Nuclei & Particles CNRS press release, 19 march 2025

The Euclid space telescope, nicknamed “the detective of the dark universe,” has now delivered its first sample of scientific data characteristic of its mission (Quick-release 1 or Q1). With highly detailed images of entire sections of the Universe, this space survey, which covers barely 0.5% of the expected total coverage, is already full of promise. France is playing a leading role through the massive involvement of the CNRS and its laboratories, both in the design and construction of the instruments and in the processing and analysis of the data.

More information:

Press release (only in french): https://www.in2p3.cnrs.fr/fr/cnrsinfo/le-telescope-spatial-euclid-devoile-sa-premiere-moisson-dimages-de-lunivers

Contacts at CPPM :

Stéphanie Escoffier, researcher at CNRS, Euclid-France scientific manager, in Renoir, cosmology team

William Gillard, Professor and researcher at Aix-Marseille University, head of the Renoir team

Nuclei & Particles CNRS press release, 19 march 2025

The fate of the Universe depends on the balance between matter and dark energy. The latter is the fundamental ingredient that fuels its accelerating expansion. The new results from the DESI (Dark Energy Spectroscopic Instrument) collaboration are based on the largest 3D map of our Universe ever made to trace the influence of dark energy over the last 11 billion years. Researchers have found that dark energy, previously widely considered a “cosmological constant,” may in fact evolve over time in unexpected ways.

More information:

Press release (only in french): https://www.in2p3.cnrs.fr/fr/cnrsinfo/vers-la-fin-de-la-constante-cosmologique-les-nouveaux-resultats-de-la-collaboration-desi

Contacts at CPPM :

Stéphanie Escoffier, CNRS researcher, Scientific Manager, eBoss/DESI, in Renoir, the cosmology research team

William Gillard, Professor and researcher at Aix-Marseille University, head of the Renoir team

Nuclei & Particles CNRS press release, 13 march 2025

The Vera Rubin Observatory (*) has reached a key milestone with the installation of the LSST camera on its telescope. The installation of the final optical component marks the start of the final testing phase. Next step: capturing the first light, before the launch of the LSST (Legacy Survey of Space and Time). Equipped with the largest digital camera ever designed, Rubin is preparing to collect an unprecedented volume of data on the visible universe, surpassing that of any other observatory in the world.

(*) The Vera Rubin Observatory, formerly known as the Large Synoptic Survey Telescope (LSST).

More information :

Press release (only in french): https://www.in2p3.cnrs.fr/fr/cnrsinfo/lobservatoire-vera-rubin-installe-la-camera-lsst-sur-son-telescope

Contacts at CPPM :

Dominique Fouchez, researcher at chercheur CNRS, LSST scientific manager at CPPM, in the cosmology research team, Renoir

Aurélien Marini, engineer at CNRS, LSST technical manager at CPPM

William Gillard, Professor and researcher at Aix-Marseille University, head of the Renoir team.

Nuclei & Particles CNRS press release, 14th february 2025

Type Ia supernovae are the dramatic explosions of white dwarf stars at the ends of their lives. Approximately 2 weeks later, each single event reaches a peak luminosity of 10 millions sun-like stars with a remarkable consistency between different events. We call these objects “standard candles”. Cosmologists have learned to use them to probe distances across the universe by comparing their fluxes, as further objects appear dimmer. The acceleration of the Universal expansion, awarded by the Nobel prize in 2011, has been discovered in the late 90s using ~100 of these Supernovae. Since then, cosmologists are investigating the reason for this acceleration caused by the dubbed dark energy that plays the role of an anti-gravity force across the Universe. Recent state-of-the-art Type Ia Supernovae datasets compile ~2000 objects gathered from many different telescopes and acquired for the last two decades. Interestingly, analyses of these samples suggest that dark energy may be more complicated than a simple mathematical constant in Einstein’s equation as assumed since its first discovery ; but then what ? Unfortunately, improvement of our understanding of the dark energy properties has been limited by our sparse knowledge of the exact physics responsible for the Type Ia Supernovae astrophysical phenomenon, which in turn affects our ability to derive precision distances to probe the fundamental physics of the Universe.

Press release: https://www.in2p3.cnrs.fr/en/cnrsinfo/zwicky-transient-facility-survey-publishes-its-long-awaited-sample-3628-type-ia-supernovae

CPPM Contacts:

Benjamin Racine, CNRS researcher, ZTF scientific manager, in Renoir team

William Gillard, teacher-researcher at Aix-Marseille University, head of the Renoir team

Nuclei & Particles CNRS Press release, 14th january 2025

After nine years of construction, the Vera C. Rubin Observatory (*) is just a few months away from the start of its ten-year mission: to make a film about the fine evolution of our night sky and the depths of the cosmos on the scale of an entire hemisphere. In preparation for this monumental production, the observatory has just successfully completed a series of comprehensive tests of the observing system using a technical test camera (ComCam), marking the green light for the final stage of Rubin's construction: the installation of the 3200-megapixel LSST camera (LSSTCam), the world's largest digital camera.

The test camera, or commissioning camera (ComCam), consists of a mosaic of nine CCD sensors totalling 144 megapixels and covering an area almost twice the size of the full moon. During the seven-week ComCam technical test campaign, from October 24 to December 11, 2024, around 16,000 images were taken to test the Rubin Observatory's hardware and software systems, as well as the image processing pipeline.

(*) The Vera C. Rubin Observatory, formerly known as the Large Synoptic Survey Telescope (LSST).

More information:

Press release (only in french): https://www.in2p3.cnrs.fr/en/cnrsinfo/rubin-observatory-declared-fit-after-3-months-tests-test-camera

CPPM Contacts:

Dominique Fouchez, CNRS researcher, LSST scientific manager at CPPM, Renoir team

Aurélien Marini, CNRS engineer, LSST technical manager at CPPM.

William Gillard, teacher-researcher at Aix-Marseille University, head of the Renoir team

An extraordinary event consistent with a neutrino with an estimated energy of about 220 PeV (220 x 1015 electron volts or 220 million billion electron volts), was detected on February 13, 2023, by the ARCA detector of the kilometre cubic neutrino telescope (KM3NeT) in the deep sea. This event, named KM3-230213A, is the most energetic neutrino ever observed and provides the first evidence that neutrinos of such high energies are produced in the Universe. After long and meticulous work to analyse and interpret the experimental data, today, February 12, 2025, the international scientific collaboration of KM3NeT reports the details of this amazing discovery in an article published in Nature.

The detected event was identified as a single muon which crossed the entire detector, inducing signals in more than one third of the active sensors. The inclination of its trajectory combined with its enormous energy provides compelling evidence that the muon originated from a cosmic neutrino interacting in the vicinity of the detector.

“KM3NeT has begun to probe a range of energy and sensitivity where detected neutrinos may originate from extreme astrophysical phenomena. This first ever detection of a neutrino of hundreds of PeV opens a new chapter in neutrino astronomy and a new observational window on the Universe”, comments Paschal Coyle, KM3NeT Spokesperson at the time of the detection, and researcher at CNRS Centre National de la Recherche Scientifique – Centre de Physique des Particules de Marseille, France.

Contacts:

Paschal Coyle, CNRS researcher, previous spokesperson for the KM3NeT Collaboration, Manager for Laboratoire Sous-marin Provence Méditerranée

Damien Dornic, CNRS resarcher, deputy spokesperson for the KM3NeT Collaboration

More information:

• CNRS press release: https://www.cnrs.fr/en/press/first-detection-ultra-high-energy-neutrino

• Publication « Observation of an ultra-high-energy cosmic neutrino with KM3NeT » : https://doi.org/10.1038/s41586-024-08543-1

• Multimedia folder : https://images.cnrs.fr/en/node/102771

• Videos - Resources : https://www.cppm.in2p3.fr/web/en/research/astroparticles/index.html

CNRS press release, February 4, 2025

The ODISSEE project, funded by the European Union, aims to develop innovative technologies and methodologies for processing the unprecedented volume of scientific data produced by research infrastructures such as CERN's HL-LHC and SKAO. In particular, it plans to use AI to process data on the fly. On-the-fly data processing is a major challenge in research in the physical sciences, and SLICES RI's contribution will be crucial to the project's success. Coordinated by Damien Gratadour, a CNRS researcher at the Laboratoire d'instrumentation et de recherche en astrophysique (CNRS/Observatoire de Paris-PSL/Sorbonne Université/Université Paris Cité), ODISSEE draws on the European HPC ecosystem to open up a new era in science, helping to unravel fundamental mysteries such as the nature of dark matter

More information:

Press release (only in french): https://www.cnrs.fr/fr/presse/lancement-du-projet-europeen-odissee-lia-pour-traiter-le-deluge-de-donnees-du-skao-et-du-hl

CPPM Contact:

Dorothea vom Bruch, CNRS researcher, LHCb team.

CNRS Nuclei & Particles press release, January 8, 2025

The European Commission announced this Tuesday, January 7, that it has granted the Cherenkov Telescope Array Observatory (CTAO) the status of a European Research Infrastructure Consortium (ERIC), a specific legal form under European Union law that facilitates the creation and operation of research infrastructures of European interest. CTAO thus becomes the 29th ERIC created since 2009.

More information:

Press release: https://www.in2p3.cnrs.fr/en/cnrsinfo/ctao-gamma-ray-observatory-promoted-european-research-infrastructure-consortium

CPPM Contact:

Heide Costantini, head of the astroparticle photon team.