June’s festival of physics

This week has seen Physics at the LHC (PLHC) 2012, the last of the particle physics conferences before ICHEP, the major conference for our field this year. Whereas at ICHEP we can look forward to the first results from analyses of 2012 data, PLHC, held in Vancouver, was an opportunity to see the impressive amount of physics that has already been extracted from last year’s data. From new measurements of known physics with unprecedented precision to the first observations of new composite particles, the breadth and depth of physics on display was impressive.

But with the focus on the LHC, it’s important to remember that our flagship facility is not the only show in town. Next week, Fermilab will be celebrating the incredible journey of the Tevatron, a machine that was at the forefront of our field for a quarter of a century, and whose data are still yielding good results a year after its last beams were extracted. I will have the honour of representing CERN at that celebration, and will have many valuable memories to share to illustrate the deep-rooted collaboration between our laboratories.

Another component of June’s celebration of particle physics is this week’s neutrino conference in Kyoto, which saw the final chapter in the story of the time it takes for neutrinos to travel from CERN to the Gran Sasso laboratory. This has been an interesting chapter in our history, and in many ways has revealed much of the best about the scientific method. When the OPERA experiment found a measurement it could not explain, there was no hesitation to hold it up for greater scrutiny. No extravagant claims were made by the collaboration, which simply stated a desire to understand the measurement. In response to that call, particle physicists did what they do best: they collaborated.

In Kyoto, four experiments from Gran Sasso and one from Fermilab presented their results, which all now show beyond a shadow of doubt that neutrinos do indeed respect Einstein’s cosmic speed limit. This is a story that’s been much in the public eye, most of the time for the right reasons. People are interested in science and in the way science works. Through this story, they’ve been able to follow that process, in all its detail, and in the words of Le Monde newspaper, it illustrated ‘Scientific doubt, an exemplary attitude’. In another development reported in Kyoto, the OPERA experiment showed evidence for the appearance of a second tau neutrino in the CERN muon-neutrino beam. This is an important step towards understanding the fascinating science of neutrino oscillations.

As we look forward to ICHEP and beyond, we, and the watching world, can look forward to new physics, and to many more stories that reveal the nature of the scientific method: through careful, evidence-based and self-critical analyses, with competitive collaboration leading to corroborated results. This is, without a doubt, the best methodology humanity has ever devised.

Rolf Heuer