This is a month of change at the CERN particle-physics lab near Geneva with the Italian physicist and former ATLAS spokesperson Fabiola Gianotti becoming the15th director-general of the lab since it was founded in 1953. On 1 January she succeeded Rolf-Dieter Heuer, who has stepped down after seven years in charge to take up a place on a new seven-member panel that will provide scientific advice to the European Commission.
Gianotti was chosen to succeed Heuer in late 2014 and spent last year shadowing her German predecessor to get prepared for the role. “My priority as CERN director-general will be to expand and maintain CERN’s excellence in four areas: science; technology and innovation; education; and peaceful collaboration,” Gianotti told physicsworld.com.
To help her accomplish these goals, in late 2015 she announced three new CERN directors, whose appointments were quickly approved by the lab’s council that is run by its 21 member states. They also took the reins of the lab on 1 January. Gianotti’s fresh management team is made up of four other CERN directors. The quartet includes the particle physicist Eckhard Elsen, who was formerly at the University of Hamburg and the DESY lab in Hamburg. He is the new director for research and computing, taking over from the Italian physicist Sergio Bertolucci, who had held the position since 2009.
Change at the top
Gianotti has also changed the structure of the directorate to introduce two new roles. Previously, CERN had a director for administration and general infrastructure – a position held by Sigurd Lettow. This position has now been split into two. Martin Steinacher, a former chair of CERN’s finance committee, will become the lab’s director for finance and human resources, while Charlotte Warakaulle, former head of the United Nations Library in Switzerland, will be CERN’s director for international relations.
Meanwhile, the CERN council also approved the re-appointment of Frédérick Bordry as director for accelerators and technology. He has been at the lab since 1986 and has been director of accelerators and technology since 2014 when he replaced Lyn Evans. “We have made some changes in the organizational structure”, says Gianotti. “But it is no big revolution.”
Targeting high luminosity
During his five-year term, Elsen will be in charge of the entire scientific programme carried out at CERN. Elsen has extensive experience in particle physics, having worked on a range of experiments such as JADE and H1 at DESY, OPAL at CERN, as well as DELCO and BaBar at the SLAC National Accelerator Laboratory in the US. Until 2014 he was also chairman of the Large Hadron Collider Committee (LHCC), which plans, discusses and reviews the entire research programme carried out at the LHC.
“If new physics is there we can discover it, but it is in the hands of nature” Fabiola Gianotti, CERN director-general
Elsen told physicsworld.com that one of his first priorities will be to see what comes out of the LHC’s “Run II”, which began last year and will continue until 2018. It has routinely achieved collision energies of 13 TeV – almost double that reached during the LHC’s first run, when the Higgs boson was discovered. LHC physicists are hoping that Run II will not only lead to a better understanding of the Higgs mechanism, but also could throw up new particles and physics beyond the Standard Model. “My aim for the year is to do our best to deliver and collect high-quality data from the 13 TeV run,” says Gianotti. “If new physics is there we can discover it, but it is in the hands of nature.”
The LHC was originally designed for collisions at 14 TeV, rather than the current maximum of 13 TeV, and running at the higher energy will require the magnets being “trained” for that energy. However, Gianotti admits that running at 14 TeV is not at the top of her to-do list. “We will have to see how the magnets react to training for higher energies,” she says. “We will evaluate later on whether to go to 14 TeV or not.” Elsen highlights the LHC’s high-luminosity upgrade, dubbed “HL-LHC“, as another of the lab’s priorities for the new directorate.
HL-LHC will have a beam luminosity 10 times that of the current LHC and will require upgrades to the collider’s injection system to ensure the beam quality is good and stable enough. Improvements must also be made to the LHC’s main detectors – ATLAS, CMS, ALICE and LHCb – to handle the increased number of events.
Plans in place
Elsen says that CERN is “near to completing how to fund” HL-LHC, adding that it would cost around €500m for ATLAS and CMS, while the price tag for the other experiments will be around €60m. Bordry agrees with Elsen that HL-LHC is a big priority for the lab. “We now have all the plans,” he says. “So we have to implement it.” CERN’s directors are also interested in what will come beyond the LHC. Bordry highlights two studies, both led by CERN, for future particle colliders that would replace the LHC. “The role of director is a strategy role,” says Bordry. “My role is to prepare the future of CERN and particle physics.”
One design is the Compact Linear Collider (CLIC), which would smash electrons and positrons together at 3 TeV. Unlike protons – which are made of quarks – electrons and positrons are fundamental particles and this means that their collisions produce far fewer unwanted particles. As a result, such a collider could be used to make high-precision measurements of the Higgs as well as other particles that the LHC may find in the future. Construction of CLIC could begin in the 2030s when the LHC shuts down.
The other collider is a much more ambitious circular proton–proton machine that could run at 100 TeV to search for new particles. Such a collider would have a circumference of 80–100 km, making it much larger than the 27 km LHC. Yet Bordry is keeping his options open in terms of developing novel technologies. “We also have to look at how plasmas could be used to drive a proton beam,” he says.