Future Collider Forum: Welcome & Scope and Organisation Karsten Köneke, Frank Simon, Georg Weiglein April 16 2021 Present situation: Higgs and beyond The Higgs-boson discovery at the LHC in 2012 has established a non-trivial structure of the vacuum, i.e. of the lowest-energy state in our universe. The origin of mass of elementary particles is related to this structure: mass arises from the interaction with the Higgs field. The vacuum structure is caused by the Higgs field through the Higgs potential. We lack a deeper understanding of this! We do not know where the Higgs potential that causes the structure of the vacuum actually comes from and which form of the potential is realised in nature. Experimental input is needed to clarify this! → Identify the underlying dynamics of electroweak symmetry breaking; so far only phenomenological description (similar to Ginzburg-Landau theory of superconductivity) 2 Further science goals and open questions ● Determine the structure of the Higgs potential ● Discriminate between: - single doublet and extended Higgs sector (new symmetry?) - fundamental scalar and compositeness (new interaction?) ● Find out what protects the Higgs mass from physics at high scales ● Unravel the connection to dark matter, to the imbalance between matter and anti-matter in the universe, and to the phase of inflation in the early universe; nature of the ``dark sector’’ of the universe (accounts for 96% of it)? ● Origin of the observed patterns of flavour (quarks, neutrino physics)? ● How is gravity related to the quantum world? Quantum structure of space-time? Are there more than three dimensions of space? 3 ● Unification of the fundamental interactions of nature? Future Collider Forum: Motivation & Goals ● Within the context of the Terascale Alliance a successful Linear Collider Forum has been established that serves as a platform for the German community in this area regarding activities at the accelerator, detector and theory level (Convenors: Ivor Fleck, Gudrid Moortgat-Pick, Sabine Riemann, Frank Simon) ● In light of the recent update of the European strategy for particle physics, and as a long-term preparation for the upcoming one, the idea was raised to widen the scope of the existing forum to a Future Collider Forum ● The goal of this forum is to support the activities in Germany regarding future colliders at the energy frontier ○ Forum for all projects: Compact Linear Colider (CLIC), Future Circular Collider (FCCee/eh/hh), International Linear Collider (ILC), Muon Collider,... ○ Foster the interaction between physics studies (experiment and theory) and activities on the detector and accelerator side 4 ○ Exploit synergies between the activities on the different future projects Motivation & Goals ● Reduce the threshold for contributions in individual groups: one Forum for Future Collider (FC) activities and exchange on the “working level” ○ Allow to reach critical mass also with smaller contributions ○ ``Community Meeting’’, increase of visibility, especially for younger members ● Foster connections with ongoing activities at the national (e.g. ``Future Facilities Platform’’ of the Quantum Universe Excellence Cluster (Hamburg), ...) and international level (European Committee for Future Accelerators (ECFA) study on a Higgs factory, Snowmass process, ILC International Development Team (IDT) structure, international working groups, …) 5 Organization, Communication & Concepts Organization: ● Three coordinators: Karsten Köneke, Frank Simon, Georg Weiglein ● Get in touch: [email protected] Communication: ● Mailing list: [email protected] To subscribe: email with subject “subscribe fcforum” to [email protected] Concept: Central element: Workshops - an individual workshop per year and in addition a meeting as part of the Terascale Alliance yearly meeting ○ “Working meetings” - with contributions from individual studies, especially from students and postdocs; interaction between different projects; long-term: coherent comparisons ○ Getting started: make use of the “tutorials” for future colliders in the Snowmass context 6 Kick-off Meeting: the Plan for Today Main idea: give everybody the opportunity to see what other groups are doing and planning to do… get to know our community! On today’s agenda: ● Introduction: Strategies, Projects & Initiatives ○ To summarize the background, environment, and to set the scene ● Brief overview of ongoing and planned activities from many groups ○ This is where you will get to know the groups ● Discussion: Organisation; Strategy & Germany; What do we need beyond LHC? ○ Presentation and discussion on ideas and plans for our organization of the Future Collider Forum ○ Open discussion on how to go forward... 7.