Meet us

Alain Blondel

FCC-ee Physics Co-coordinator, Chair of FCC Physics Coordination Group
Nationality:
French
Home institution:
DPNC, Université de Genève
What we do in our working group:
We do a great team with Patrick Janot and the two theorists, John Ellis and Christophe Grojean, and the conveners of the physics groups. It is a bit difficult to morph "a small group of dedicated individuals", into the "professional design study", but thanks to the presence of our fantastic accelerator colleagues, Michael Benedikt, Frank Zimmermann and Jorg Wenninger, we make great progress in making the whole thing real. It is an extremely stressful but exciting task at the moment: the circular factory felt like a mouse between two (large and) powerful communities, the Hadron collider and the ILC communities, so we were looked at rather suspiciously at the beginning. Little by little the physics is speaking for us, and the idea of a Higgs, Z, W and top Factory is more and more becoming accepted.
Why we need FCC-ee and the FCCs:
I have worked on LEP3, TLEP, FCC-ee since before the beginning. The name LEP3 came up in a question in the joint ECFA-EPS session in Grenoble on 23 July 2011, when I asked Pippa if ATLAS and CMS would be suitable for a Higgs factory that would be 'LEP3' -- she was not sure how to answer the question, but she understood what LEP3 was immediately. The full accelerator concept was born after a presentation on b-factories at the ICFA seminar at CERN in October. Together with Frank Zimmermann, Roy Aleksan and many others, we came up with the idea of building a new tunnel that people wanted anyways for a high energy hadron collider - so it became the '100km', then in summer 2012, 'TLEP'. When CERN decided to create an official design study for the '100km' they "convinced" us to call the machine FCC-ee. This is a name that is difficult to pronounce, even in Russian. It is often called the TeraZ, OkuW, MegaHiggs and Megatops, or Z, W, H, t factory - maybe we should call it the "Electroweak Factory". Some people are pessimistic about funding (time will tell), but these machines are really exciting, and apparently very well fit for the physics situation that nature has placed in front of us.

Krisztian Peters / Markus Klute

Conveners of WG3: H(126) Properties
Nationality:
German-Hungarian / German
Home institution:
CERN / Massachusetts Institute of Technology
What we do in our working group:
The main objectives of our working group is to estimate the potential sensitivity to various Higgs boson property measurements which can be reached with the FCC-ee. Since the ultimate sensitivity naturally depends on the machine and detector parameters, we are currently exploring benchmark processes to understand the necessary detector requirements. The main benchmarks and deliverables are listed on our FCC-ee WG3 webpage. These processes will be the main focus to study in the coming year in order to understand necessary tracking impact parameter and momentum resolution, resolution of the calorimeter to jets, photons and electrons, as well as constraints on the beam energy spread.
Why we need FCC-ee and the FCCs:
A future circular electron-positron collider, such as the FCC-ee, will be the ultimate machine for electroweak precision measurements to pinpoint signs of new physics. The Higgs boson, the only scalar particle of the Standard Model, provides a new and possibly unique way for such discoveries by measuring the properties of the Higgs particle with the greatest possible detail. These measurements are one of the most important goals of the FCC-ee, which could produce more than 2 million Higgs bosons over the period of five years. With the clean environment of electron-positron collisions and the large number of produced Higgs bosons, the FCC-ee could reach model independent Higgs boson coupling measurements down to per-mille level experimental uncertainties, which are potentially sensitive to multi-TeV range new physics interacting with the scalar sector.

Peter Skands

Co-convener of WG5: QCD and gamma-gamma physics
Nationality:
Danish
Home institution:
Monash University Melbourne
What we do in our working group:
In the QCD part of this group, we study what is required of the detectors in terms of coverage, resolutions, tagging efficiencies, and particle identification capabilities, in order to provide a battery of QCD-jet and fragmentation constraints that could improve by an order of magnitude the ones from LEP and other previous ee colliders. The aim is to constrain all aspects of QCD fragmentation to the few-% level and provide a set of high-precision fragmentation models to base the future FCC-hh studies on. These studies are chiefly done at Tera-Z, at which the statistics for Z decays will be a million times that of LEP, such that systematic uncertainties will dominate far into the tails of very rare phenomena such as Sudakov-suppressed regions, multi-jet events with four or more hard jets, subleading-colour effects, and the formation of very rare hadron states, such as triple-strange and heavier baryons.
Why we need FCC-ee and the FCCs:
The full-on excitement and intense stream of scientific results now coming from the LHC are the products of decades of planning and construction. This is the process that is being initiated now with the FCC and FCC-ee studies, with a view decades down the line, to what machines we can provide the post-LHC generation of scientists with. This sort of planning exercise is a fascinating part of basic research to be involved in, allowing one to imagine machines and detectors that do not yet exist, and speculate on what properties they need to have, in order to perform the most revealing measurements.