Base programmes 2020


Programme Leader

Robert Fleischer

Spectrum of research highlights

  • E. Laenen, J. Sinninghe Damste, L. Vernazza, W. Waalewijn and L. Zoppi, Towards all-order factorization of QED amplitudes at next-to-leading power
  • A. Basdew-Sharma, F. Herzog, S. Schrijnder van Velzen and W.J. Waalewijn, One-loop jet functions by geometric subtraction
  • C.B. Marinissen, R. Rahn and W.J. Waalewijn, …, 83106786, 114382724, 1509048322, 2343463290, 27410087742, … efficient Hilbert series for effective theories
  • M. van Beekveld and W. Beenakker, The role of the threshold variable in soft-gluon resummation of the t\bar{t}h production process
  • F. Faura, S. Iranipour, E. R. Nocera, J. Rojo and M. Ubiali, The Strangest Proton?
  • R. Abdul Khalek, J.J. Ethier, J. Rojo and G. van Weelden, nNNPDF2.0: quark flavor separation in nuclei from LHC data
  • J.J. Ethier and E.R. Nocera, Parton Distributions in Nucleons and Nuclei
  • A. Garcia, R. Gauld, A. Heijboer and J. Rojo, Complete predictions for high-energy neutrino propagation in matter
  • R. Gauld, A. Gehrmann-De Ridder, E.W.N. Glover, A. Huss and I. Majer, Precise predictions for {WH}+jet production at the LHC
  • M.Z. Barel, K. De Bruyn, R. Fleischer and E. Malami, In Pursuit of New Physics with B_d^0\to J/\psi K^0 and $B_s^0\to J/\psi\phi$ Decays at the High-Precision Frontier
  • M.F.M. Lutz, U. Sauerwein and R.G.E. Timmermans, On the axial-vector form factor of the nucleon and chiral symmetry
  • R. Beekveldt, M. Borinsky and F. Herzog, The Hopf algebra structure of the R$^{∗}$-operation
  • M. Borinsky, Tropical Monte Carlo quadrature for Feynman integrals
  • T. Ueda, T. Kaneko, B. Ruijl and J.A.M. Vermaseren, Further developments of FORM
  • Y.P. Wu and K. Petraki, Stochastic Baryogenesis
  • J. Fumagalli, M. Postma and M. Van Den Bout, Matching and running sensitivity in non-renormalizable inflationary models
  • M. Boers and E. Pallante, Conserved vector current in QCD-like theories and the gradient flow
  • S. Biondini, D. Boer and R. Peeters, The hierarchy problem and fine-tuning in a decoupling approach to multi-scale effective potentials
  • J.W. van Holten, Conformal symmetry and supersymmetry in Rindler space
  • A. Anabalon, B. de Wit and J. Oliva, Supersymmetric traversable wormholes

Computer codes

  • Work towards FORM 5.0


  • For an overview of the outreach and activities in the theory group, follow social media channels (instagram and twitter):,
  • Nikhef magazine DIMENSIES (Autumn 2020) with a spotlight on the theory group.
  • Thesis summary prize winner Melissa van Beekveld: ‘Written for my parents’
  • INTERVIEW  (Bert Schellekens) ‘Snaartheorie geeft geen uniek antwoord, en dat is goed nieuws’
  • INTERVIEW (Piet Mulders) ‘De vraag waaróm kun je altijd blijven stellen’


In view of the coronavirus pandemic, the visitor program has put on hold. We stay in touch with our international colleagues virtually.

Physics Data Processing

Programme Leader

Jeff Templon

Main points: scientific

  • Acceptance of Nikhef-led “Allen” GPU-based framework as the baseline for LHCb’s High-Level Trigger.
  • Start of FuSE (Fundamental Sciences e-Infrastructure), a joint Dutch computing infrastructure for large-scale science (LHC, SKA, and KM3NeT), in collaboration with ASTRON and SURF.
  • Progress on the European Open Science Cloud, based on the Nikhef-driven, AARC-based common identity federation.  This follows from one of the main thrusts of the Nikhef group, “Interoperability of trust and identity standards among global infrastructures.”

Main points: technical

  • 400 Gb connection to CERN realised; the first international 400 Gb connection worldwide.
  • New compute nodes
    • 57 AMD EPYC 64-core machines
    • GPU-enabled nodes for the local “stoomboot” cluster
      • 7 with dual AMD Radeon MI50 cards
      • 2 with dual Tesla V100 cards
  • Experimental AMD GPU cluster installed (collaboration with SURFsara and AMD)
  • New storage : 1.6 petabyte housed in NetApp systems
  • The new storage powered the retirement of our venerable DPM-based grid storage system and the migration of existing data and capacity to dCache.
  • ARC Computing Element implemented for users of the European Grid Infrastructure and the LHC Computing Grid
  • Installation of new HTCondor cluster for Gravitational Waves
  • Retirement of the last CentOS 6 systems.

Key positions in collaborations

WLCG Overview Board: Jeff Templon

Dutch National e-Infrastructure Executive Team: Jeff Templon and David Groep

Computer codes

OpenID Connect Federation – Metadata Signing Service

OpenID Connect Federation – Trust Chain Validation Library

Main paper

Allen: A High-Level Trigger on GPUs for LHCb, R. Aaij et al., Computing and Software for Big Science Vol. 4, Article number: 7 (2020).

Detector R&D

Programme Leader

Niels van Bakel

Main points: scientific

  • The DR&D group, together with the three Nikhef LHC experiments and the Electronics department, will focus on fast sensors for 4D tracking in LHC detector upgrades. Next to the ongoing research on fast hybrid detectors, we started working on monolithic active pixel sensors (MAPS). The ultimate goal is to reach order ten picosecond timing (rms) in pixel chips.
  • Advanced Virgo reached the observing-run three (O3) target sensitivity: a binary-neutron star (BNS) detection range of 60 megaparsecs.

Main points: technical

  • The Timepix4 pixel chip arrived, and most of the first version of the chip worked right away! Remaining issues are understood and resolved in the next version. This new pixel chip with 80 picosecond time resolution (rms) makes faster timing possible in tracking detectors and X-ray imaging.
  • Our latest SPIDR4 readout system, capable of 160 Gb/s data rate per chip, has been used for testing the Timepix4 pixel chip.
  • Installation and commissioning of the two-photon absorption (TPA) set-up in the DR&D lab allows us to study the charge collection properties of semiconductor sensors in great detail by liberating charge in a voxel instead of along a line.
  • The first wavefront sensors for the Laser Interferometer Space Antenna (LISA), a detector in space to accurately measure gravitational waves, are fabricated and extensively tested. The results of these Indium-Gallium-Arsenide quadrant photo-diodes are promising, and plans for further development became concrete.
  • The first measurement of frequency-dependent squeezing below 100 Hz has been performed in the Japanese TAMA prototype, a former gravitational wave detector currently used to develop new technologies.
  • Development and realization of many parts of the frequency depending squeezer for Advanced Virgo – together with the Nikhef Gravitational Wave group.
  • Upgrade our X-ray setup to perform ‘colour micro computerized tomography (CT)’ scans to improve image resolution and better material decomposition.
  • Development of a muon tomography system in collaboration with TU-Delft Faculty of Aerospace Engineering for Asteroid Muography; using muons to characterize the interior of near-earth astroids via a detector on board a small satellite.
  • A next-generation miniaturized accelerometer is under development, a sensor measuring acceleration with integrated signal processing, aiming at 1 ng/sqrt(Hz) sensitivity. This sensor is fabricated in micro-electro-mechanical systems (MEMS) technology, and we improved the MEMS production process. Besides, a next test chip is submitted for fabrication to test the different signal processing blocks.

Key positions in collaborations

  • Commissioning coordinator Advanced Virgo – Matteo Tacca
  • Chair of the wavefront sensing and control work package in the Optics Division of the Einstein Telescope Instrument Science Board – Martin van Beuzekom
  • European Community for Future Accelerators (ECFA), Detector R&D Roadmap – Niels van Bakel
  • NWO research community Physics for Technology and Instrumentation (PTI) – Niels van Bakel


  • AIDAinnova – Advancement and Innovation for Detectors at Accelerators – Horizon 2020 project approved for funding – Martin van Beuzekom
  • NWA-ORC Dutch Black Hole consortium approved: including a work package on R&D for thermal noise in cryogenic systems – Matteo Tacca, Alessandro Bertolini

Main papers in 2020

  • Frequency-Dependent Squeezed Vacuum Source for Broadband Quantum Noise Reduction in Advanced Gravitational-Wave Detectors – Yuefan Guo, Matteo Tacca, Marco Vardaro et. al., Phys. Rev. Lett. 124, 171101 – Published 28 April 2020.
  • Charge collection properties of prototype sensors for the LHCb VELO upgrade – R. Geertsema, K. Akiba, M. van Beuzekom, et al – Accepted for JINST (arXiv:2010.10147).