Description
The process of shaping the input from the Netherlands for the European Strategy Update has been led by the Dutch National Institute for Subatomic Physics Nikhef. It has been a structured, open and iterative effort, starting early-2024 by broadly informing our community, followed by multiple days of in-depth presentations and discussions. We concluded the process with an open session to refine the statements that were formulated during the process, and that now form the basis of this document. As the detailed ESPP inputs for the future collider options will become available after the March deadline, this document focusses on which considerations are viewed as most important in deciding on the next flagship collider.
We are convinced that a new flagship collider is essential and that it should be located at CERN, but it should not affect the completion of the high-luminosity phase of the LHC (HL-LHC). We see physics as the primary motivation for a future collider, with the study of the Higgs boson and the search for physics beyond the Standard Model as main targets. While physics is the primary driver, other considerations were also viewed as important in deciding on the next collider: it should offer an attractive and innovative R&D programme and the time gap between the HL-LHC and the next flagship collider has to be small or there should be an attractive physics programme in the gap.
Flexibility is important to adapt to new physics results and new technologies, and environmental impact must be addressed. Furthermore, sufficient career opportunities are essential to continue to attract and foster physicists and technologists, and a strong communication strategy is imperative for the viability of our field.
Finally, there was a strong sentiment that non-collider (astro)particle physics should be included in the ESPP, and that the next collider project should not come at the expense of a diverse scientific programme in Europe in terms of resources.
