Rikkert Frederix

Former member
Member from December 2005 to September 2009
Current position: Post-doc in Zurich
Oct. 2008 - Sep. 2009
Marie Curie Early Training Theory Fellow at CERN.

Dec. 2005 - Sep. 2009 (expected)
PhD Student at the Centre for Cosmology, Particle Physics Phenomenology at the UCLouvain. Supervisor: Fabio Maltoni.

Sep. 2004 - Nov. 2005
Master's research on "Wilson lines in pQCD" under supervision of Eric Laenen at the nikhef institute, Amsterdam.

Sep. 2000 - Nov. 2005
(Under)graduate student at Utrecht University.
Research Activities
My research interests are focused on the study of the phenomenology of the standard model (SM) and its extensions.

I have started my Ph.D. working on the MadGraph/MadEvent (MG/ME) event generator. I have implemented new interactions, in particular the effective couplings between (pseudo-)scalars and gluons/photons. This has allowed me to familiarize with the implementation of new helicity routines and vertex structures in the MG/ME framework. I have also developed a code, MadAnalysis, suitable to analyze event files (LHEF and LHCO), i.e., produce plots, set analysis cuts, etc.

ZZ resummation
I have used the expertise gained during my Master's research on perturbative QCD, and in particular in the resummation of soft radiation in production and decays of strongly interacting particles, to calculate of the NLL soft gluon effects in double Z boson production at the LHC with Massimiliano Grazzini. We have implemented the results in a Monte Carlo program and compared our results with a fixed NLO calculation and with the results from the MC@NLO event generator.

Top quark phenomenolgy
Furthermore I am interested in the phenomenology of top quark production and decays. In my first year of my PhD research I have take part to a common theoretical/experimental effort in our Centre (CP3), and proposed an improved method to set model independent bounds on the third row of the CKM matrix. In my second year I have spend quite some time to study the phenomenology of ttbar production, both in the SM and in 'model-independent' extensions. In this work we proposed a the possibility for a mass measurement of the top quark mass from the ttbar invariant mass and also a three-step analysis to discover and measure the properties of new physics resonances.

At the moment I am working in collaboration with John Campbell, Francesco Tramontano and Fabio Maltoni to study the NLO corrections to the t-channel single top production (starting from the 2->3 Born amplitude (4 flavor)).

Together with Thomas Gehrmann and Nicolas Greiner I am working on automatizing the dipole subtraction formalism for NLO in QCD calculations within the MadGraph/MadEvent framework. This includes automatic generation of the subtraction terms for the reals as well as the virtuals, and doing being able to do the (then finite) phase space integration.
Research directions:
Phenomenology of elementary particles

Non-active projects
Publications in IRMP
All my publications on Inspire

Number of publications as IRMP member: 17
Last 5 publications


CP3-16-60: The complete NLO corrections to dijet hadroproduction
Frederix, Rikkert and Frixione, Stefano and Hirschi, Valentin and Pagani, Davide and Shao, Hua-Sheng and Zaro, Marco

[Abstract] [PDF] [Journal] [Dial]
Refereed paper. December 10.
CP3-16-11: Mass effects in Higgs plus jets production
R. Frederix, S. Frixione, E. Vryonidou and M. Wiesemann

to be submitted to JHEP
Refereed paper. April 4.


CP3-14-18: The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
Alwall, J. and Frederix, R. and Frixione, S. and Hirschi, V. and Maltoni, F. and others

[Abstract] [PDF] [Journal] [Dial]
to be submitted
Refereed paper. April 4.


CP3-12-38: Diphoton production in the ADD model to NLO+parton shower accuracy at the LHC
R. Frederix, Manoj K. Mandal, Prakash Mathews, V. Ranvidran, Satyajit Seth, P. Torrielli, M. Zaro

[Abstract] [PDF] [Journal] [Dial]
10 pages
Refereed paper. September 28.


CP3-09-39: Automation of next-to-leading order computations in QCD: the FKS subtraction
Rikkert Frederix, Stefano Frixione, Fabio Maltoni and Tim Stelzer

[Abstract] [PDF] [Journal] [Dial]
Published in JHEP10(2009)003.
Refereed paper. August 14.

More publications