Louis Lyons traces the origins of the “five sigma” criterion in particle physics, and asks whether it remains a relevant marker for claiming the discovery of new physics. Disentanglement A Jackson ...

André de Gouvêa explains why neutrino masses imply the existence of new fundamental fields. Misfits Massive neutrinos are not part of the Standard Model. Credit: Symmetry After all these years, ...

The development at CERN of magnesium diboride cables and other advanced superconducting systems for the High-Luminosity LHC is also driving applications beyond fundamental research, describes Amalia ...

With a new measurement imminent, the Courier explores the experimental results and theoretical calculations used to predict ‘muon g-2’ – one of particle physics’ most precisely known quantities and ...

Jochen Klein and Marco van Leeuwen describe the physics motivation, detector concept and projected performance of a next-generation heavy-ion programme for LHC Runs 5 and 6. Brand new ALICE 3 is built ...

In lead collisions at the LHC, some of the strongest electromagnetic fields in the universe bombard the inside of the beam pipe with radioactive gold. By following the collision fragments, John Jowett ...

Patrick Koppenburg and Marco Pappagallo survey the 23 exotic hadrons discovered at the LHC so far. Twenty-three exotic states Five pentaquarks and 18 tetraquarks have been discovered so far at the LHC ...

Marek Karliner and Jonathan Rosner ask what makes tetraquarks and pentaquarks tick, revealing them to be at times exotic compact states, at times hadronic molecules and at times both – with much still ...

From targets to absorbers, beam-intercepting devices are vital to CERN’s accelerator complex. Marco Calviani describes the major upgrades taking place to prepare for the high-luminosity LHC, and the ...

What a proton is depends on how you look at it, or rather on how hard you hit it. A century after Rutherford’s discovery, our picture of this ubiquitous particle is coming into focus, says Amanda ...

In the summer of 1968, while a visitor in CERN’s theory division, Gabriele Veneziano wrote a paper titled “Construction of a crossing-symmetric, Regge behaved amplitude for linearly-rising ...

Vivian Poulin asks if the tension between a direct measurement of the Hubble constant and constraints from the early universe could be resolved by new physics. On large scales the dominant motion of ...