Mar 30 – 31, 2017
Emmanuel College, Cambridge
Europe/London timezone

Workshop on renormalisation and factorisation scale choices for precision predictions of cross sections at the LHC


  • Perturbative predictions of any LHC observable depend on factorization and renormalization scales
  • Scale choices are important in any kinematics but will be critical for describing still-unexplored regimes like:
    • boosted regime/particle productions at high pT 
    • production and decay of high mass particles
    • jet physics, especially for jets at large rapidity
  • Guessing the right scale for a process is not an easy task
  • Is there such a thing as correct scale choice?
    • Or are there only more-or-less smart choices?
    • There are definitely very wrong choices, which lead to an unstable perturbative behavior


The convening of this meeting has been compelled by a convergence of new LHC-related developments:

  • The calculation of almost all major two-to-two processes at NNLO
  • NLO calculations now allow detailed access to even the most subtle effects
  • Mature LO and NLO merging techniques that have been very successful in bridging various multiplicities
  • Resummation at NNLL is turning into a bread-and-butter phenomenology

These new developments would make it possible to quantify the impact of various scale-setting procedures; this was not possible in the past.

Workshop goals:

  • To draw attention to the last missing piece in the precision physics puzzle: the choice of unphysical factorisation and renormalisation scales
  • Bringing together leading researchers in order to debate ways of setting scales
  • Be the first step towards harmonised scale-setting accord across LHC processes and for the benefit of precision LHC phenomenology

Related Workshop:

The Workshop will immediately follow the annual Workshop on Parton Showers and Resummation PSR2017. Both Workshops will be held in the same venue. Participants may wish to take advantage of this opportunity and attend both meetings. More information about PSR2017 is available here:


  • Michal Czakon (RWTH Aachen University)
  • Joey Huston (Michigan State University)
  • Alexander Mitov (Cambridge University)
  • Bryan Webber (Cambridge University)
  • Malgorzata Worek (RWTH Aachen University)
Emmanuel College, Cambridge
University of Cambridge, Cambridge, UK