Mark Rayner

home.cern — Neutrinos are tricky beasts. Alone among known fundamental particles, they suffer from an identity crisis - if it were possible to put them on a weighing scale, you would unpredictably measure one of three possible masses.

home.cern — Picture two children playing on swings in a playground. One is a daredevil, launching themselves high off the ground in big arcs. The other daydreams, swinging gently. Now picture the children holding either end of a long spring. Tension in the spring now accelerates the daydreaming child forwards and backwards to follow their friend, whose swings are slowed and shortened.

home.cern — CERN is launching a new podcast series on artificial intelligence. The series looks forward to the first edition of the Sparks! Serendipity Forum in September, when over 30 leading thinkers will converge on the laboratory for high-level multidisciplinary discussions designed to spark ethical innovation.

CERN Courier — The existence of an eV-scale sterile neutrino looks less likely today than at any time in the past 20 years. Such a particle has long been considered to be the simplest explanation for several related anomalies in neutrino physics, but results released yesterday by Fermilab's MicroBooNE collaboration disfavour its existence relative to the Standard Model.

CERN Courier — The BICEP/Keck collaboration has published the strongest constraints to date on primordial gravitational waves, ruling out parameter space for models of inflation in the early universe.

CERN Courier — Excitement is building in the search for sterile neutrinos - long-predicted particles which would constitute physics beyond the Standard Model. Although impervious to the electromagnetic, weak and strong interactions, such a fourth "right-handed" neutrino flavour could reveal itself by altering the rate of standard-neutrino oscillations - tantalising hints of which were reported by Fermilab's MiniBooNE experiment in 2007.

CERN Courier — Residents of the Vatican Observatory describe life as a full-time physicist in the church. "Our job is to be part of the scientific community and show that there can be religious people and priests who are scientists," says Gabriele Gionti, a Roman Catholic priest and theoretical physicist specialising in quantum gravity who is resident at the Vatican Observatory.

CERN Courier — The first Sparks! Serendipity Forum at CERN will bring together world experts in artificial intelligence in a spirit of multidisciplinary collaboration. Mark Rayner spoke to some of the participants in the run-up to the September event.

CERN Courier — The COMPASS experiment at CERN has reported the first direct evidence for a long-hypothesised interplay between hadron decays which can masquerade as a resonance. The analysis, which was (1420)" signal published last week in Physical Review Letters, suggests that the "a observed by the collaboration in 2015 is not a new exotic hadron after all, but the first sighting of a so-called triangle singularity.

CERN Courier — In a significant technological advance for antimatter research, the BASE (Baryon Antibaryon Symmetry Experiment) collaboration has used laser-cooled ions to cool a proton more quickly and to lower temperatures than is possible using existing methods.

CERN Courier — All the exotic hadrons that have been observed so far decay rapidly via the strong interaction. The ccūd̄ tetraquark (T cc + ) just discovered by the LHCb collaboration is no exception. However, it is the longest-lived state yet, and reinforces expectations that its beautiful cousin, bbūd , will be stable with respect to the strong interaction when its peak emerges in future data.

home.cern — Update: Did you enjoy our April Fools' day story? If you want to find out about the antimatter research that is really going on at CERN, check out this recent update: https://home.cern/news/press-release/experiments/alpha-cools-antimatter-using-laser-light-first-time, and read all about the Antiproton Decelerator: https://home.cern/science/accelerators/antiproton-decelerator. "Do antimatter apples fall up?"