Dutch contributions to the detector upgrades of the Large Hadron Collider experiments at CERN

The Large Hadron Collider (LHC) at CERN is the world’s most powerful particle accelerator, installed in a 27 km circumference underground ring straddling the border between Switzerland and France near Geneva. Two counterrotating beams of particles are accelerated to world-record energies to collide at four locations along the ring. The collision points are viewed by huge particle detectors (ATLAS, ALICE, CMS and LHCb), to study elementary particles and their interactions. The first years of LHC operation were very successful, with as undisputed highlight the discovery of the Higgs particle in 2012. Presently, the LHC accelerator complex is being refurbished to allow operation at its full design energy and intensity. After completion in 2015, the LHC will be in an excellent position to unveil the hitherto unexplored TeV (1012 eV) energy scale. The LHC discovery potential includes: the detailed roperties of the just-discovered Higgs particle, which is supposed to be responsible for all known elementary particle masses; the nature of the matter-antimatter differences, essential to explain the matter dominance in the Universe today, 13.8 billion years after the Big Bang; the structure of the quark-gluon plasma, a state of matter assumed to have existed briefly after the Big Bang; and last, but not least, proof of physics beyond the so-called Standard Model, the immensely successful theoretical framework that accurately describes a wealth of experimental observations, but amongst others falls short to explain the nature of the mysterious dark matter in the Universe. Because of this tremendous discovery potential, the LHC is consistently ranked as the top-priority project in particle physics. As a founding member of CERN in 1954, the Netherlands has a strong track record at CERN and in particle physics. Dutch scientists have held top management positions at CERN, notably as Director General and as Research Director. Simon van der Meer’s 1984 Nobel prize (for decisive contributions to the large project, which led to the discovery of the field particles W and Z, communicators of weak interaction) was entirely CERN related while the 1999 Nobel prize for ’t Hooft and Veltman (for elucidating the quantum structure of electroweak interactions in physics) made explicit reference to the superb results of CERN’s LEP project. Since 1975 Nikhef, National Institute for Subatomic Physics, coordinates the Dutch activities at CERN. Nikhef was a founding member of the general purpose ATLAS experiment, and of the LHCb experiment dedicated to the study of the matter-antimatter differences in systems with beauty (b) quarks. In 1994 Nikhef joined the ALICE experiment, which is optimized to study the quark-gluon plasma. Nikhef has made major contributions often in collaboration with (Dutch) industry, to the construction of all three detectors. Moreover within the context of BiG Grid, the Dutch e-Science Grid, the Netherlands created NL/Tier-1, one of the 11 world-wide Tier-1 grid centres for LHC data analysis. In the second half of this decade major upgrades of both the LHC achine and the LHC experiments are envisaged to increase the event rate by an order of magnitude, to further boost the LHC discovery otential. These upgrades are essential to assess the intricacies of the Higgs mechanism (ATLAS); to reach the ultimate precision in specific b-quark systems (LHCb); to maximize the reach for the discovery of new particles (ATLAS); and to allow complementary studies of quarks and gluons under extreme conditions (ALICE). The detector upgrades heavily rely on state-of-the-art silicon strip and –pixel technologies and fast electronics, areas in which Nikhef has an excellent track record. To deal with the data analysis challenges inherent to high-luminosity LHC-operations, the NL/Tier-1 grid facility must be upgraded as well. Whereas the upgrade of the LHC machine proper is funded from the annual contributions of the CERN member-states, the upgrades of the LHC detectors and the (grid) computing facilities must be funded by the experimental collaborations. In this proposal we request in total 18.4 M€ investment funding: 12.4 M€ for the upgrades of the ATLAS, LHCb and ALICE detectors and 6 M€ for the continuation of NL/Tier-1. Dutch (high-tech) industries will be involved in the realization of these upgrades. The LHC project is a curiosity-driven research activity and attracts as such a huge interest from the general public and from the next generation of scientists. Particle physics has also proven significant societal impact, notably in high-tech areas –one of the nine recently identified research priorities (‘topsectoren’) of the Dutch government– such as nformation technology and (medical) diagnostic systems. State-of-the-art pixel detectors originating from LHC detector R&D are now used in commercially available X-ray diffraction systems. The World Wide Web (WWW), invented at CERN in the early nineties, partially explains the thriving AMS-IX location at Nikhef. Nikhef’s pioneering role in the grid compute concept is one of the reasons why the European Grid Infrastructure (EGI) is headquartered at Science Park Amsterdam.