Brief Curriculum Vitae

• since 2006: at IPPP Durham
• 2019-2024: Director of Institute for Data Science
• 2003-2006: Junior Professor at TU Dresden
• 2002-2003: Postdoc at CERN
• 2000-2001: Postdoc at Cavendish Lab, Cambridge, UK
• 1999-2000: Postdoc at Technion, Haifa, Israel
• 1994-1998: PhD student at TU Dresden, supervised by Gerhard Soff
• 1988-1994: Undergraduate studies at TH Darmstadt; diploma thesis supervised by Thomas Mannel and Thorsten Ohl

Publications

Journal Publications
Here’s my listing from Spires, the particle physics database of publications, and here’s the same from google scholar.
Book
Together with John Campbell and Joey Huston I authored The Black Book of Quantum Chromodynamics, a primer on QCD in the LHC era.

Research Areas

Particle Phenomenology
My research area is the phenomenology of particle physics – this is the branch of theoretical physics that bridges the gap between theorists who construct more abstract models for the fundamental interaction of the constituents of the matter in the Universe at the smallest distances, and the experimenters that search for and measure phenomena, for example at the LHC at CERN. Phenomenologists use these models, new and old, to make predictions for observables in experiments or to calculate quantities that allow the experimenters to interpret their data as measurements of fundamental quantities.
Monte Carlo event generators
My role in this is the construction of a simulation tool that tries to describe the experimental reality in great detail. Tools such as the ones I work on are also called event generators, since they generate “events”, the plethora of particles that are produced when particles smash into each other at large energies. In these relatively violent collision the large energies of the incident beam particles are translated into showers of elementary particles which hit the detector at velocities very close to the speed of light. Event generators are the workhorses of particle physics, and are deployed for a wide range of purposes: Their output — the simulated events — is utilised to better understand detector responses to the interaction with incident particles, to help in the planning of analyses by providing an understanding of interesting signals and their backgrounds, to subtract backgrounds from signals, and to compare the most precise calculations directly with data. To fulfil these functions, they must contain all relevant physics, from the highest energies of the order of a few TeV down to the relatively low scales of MeV that characterise hadron physics. Traditional methods of evaluating quantum field theories, based upon the perturbative expansion in coupling constants, cannot fulfil this, due to two limitations: The sheer number of outgoing particles leads to a computational complexity we cannot conquer yet, and many of the produced particles are hadrons, bound states of the fundamental quarks and gluons, which form the hadrons in a phase transition that we cannot yet describe in a quantitative way. These two problems are addressed in event generators by decomposing the simulation into different phases, characterised by vastly different energy scales.

The event generator project I work on – now for more than 25 years – is called SHERPA.

We are a team of about 10 people or so from 5 countries on two continents, who work on the development, maintenance, deployment and validation of our tool.

To be more specific (and more for the specialists), here are my current research topics:

• better description of perturbative QCD radiation through parton showers
• the connection of the parton showers to the hard sub-process – by now this can be done at next-to leading order accuracy in Sherpa for practically arbitrary processes and at next-to-next-to leading order for two relatively simple ones
• automatic calculation for multi-leg processes in – nearly arbitrary – models (matrix element generation and phase spacing)
• the interface to non-perturbative QCD (fragmentation of the partons into colourless hadrons)
• multiple interactions and the structure of hadrons
• (new) physics at collider experiments

In addition, I collaborated with experimenters from the ATLAS collaboration on measurements of Double Parton Scattering – events where more than one pair of energetic quarks or gluons collides inside a single proton-proton scattering and gives rise to highly energetic particles.

 
Data Science
From 2019-2024 I was the founding director of Durham’s Institute for Data Science. Before that I was one of two co-directors of the Durham Centre for Doctoral Training in Data-Intensive Science, held between our colleagues from Astronomy and the IPPP. We have a cohort of 15 students funded between STFC and Durham University who started in 2017, 7 students who started in October 2018, and 3 more students in 2020.

 
A foray into epidemiology
Driven by the recent COVID-19 emergency I undertook a foray into the world of epidemiology. With a number of students and colleagues we wrote a simulation that describes the spread of an infectious disease through a virtual population. We build the latter based on the very granular census of the UK – specifically England and Wales – from 2011. Our code, called JUNE is freely available on github and has been published in Royal Society Open Science. It has also been adapted by three of the students, in collaboration with the UN and WHO, to the situation in refugee camps. Its granularity allowed us in collaboration with researchers from the WHO and UN Global Pulse to infer, for the first time, social mixing matrices in these camps with a mixed-method approach.

Our model and code is being used by public health bodies, and adapted to their respective populations and some new epidemics such as the measles. Here’s also a little video where we talk about some more recent work on using satellite data to quickly model the population of refugee camps, helping us to understand and better mitigate against the spread of epidemics in these camps.

 
Past and current students
I enjoy the privilege of having worked or still working with a number of highly talented and motivated young scientists:

Academic lectures on phenomenology at collider experiments, Monte Carlo event generators etc.:

• “Monte Carlo” (3 lectures, CTEQ school 2019, Pittsburgh, July 2019)
• “QCD” (5 lectures, TASI school 2018, “Theory in an era of data”, Boulder, June 2018)
• “Simulations for High-Energy Physics”(3 lectures, Cours de Printemps du LAL, Orsay, May 2018)
• “QCD & Monte Carlo Event Generators”(3 lectures, during Maria Laach school 2016, Maria Laach, September 2016 and TRISEP school, Vancouver, June 2016)
• “QCD and Event Generators”(15 hours lectures during “Heidelberger Graduiertentage”, Heidelberg, October 2014)
• “Precision Monte Carlo”, during CTEQ school, Pittsburgh, July 2015
• “Introduction to Event generators”
  (latest lectures linked from series of four lectures, at HiggsTools school, Pre Saint-Didier, June 2015; the MCnet summer school, Kyoto, September 2011; DESY MC school, Hamburg, March 2011; MCnet summer school, Lund, July 2009; Galileo Galilei Institute, September 2007; Fermilab-CERN Hadron Collider School, June 2007)
• “Phenomenology at colliders” (series of eight lectures, at the RAL high-energy physics summer school, 2008-2009)

Some recent (and not so recent) Talks

Particle Physics

• “Sherpa for EIC” (EIC UK Meeting, York, March 2024)
• “Precision QCD simulations” (FNAL Theory Seminar, April 2023)
• “Constraining Pesky Higgs Branching Ratios at the LHC and Beyond” (Higgs Days, Santander, September 2022)
• “Measurements to Improve Hadronization Models” (ECFA Workshop, Virtual, October 2022)
• “A new approach to color-coherent parton evolution: ALARIC” (Gearing up for High-Precision LHC Physics, Workshop at MIAPbP Munich, August 2022)
• “The Edge of Precision in simulations for the LHC” (Fermilab Wine & Cheese, July 2019)
• “Sherpa status” (MCnet meeting, CERN, April 2018)
• “The Quest for Precision in Simulations for the LHC” (Seminar, Madrid, January 2018)
• “QCD at the Energy Frontier” (WE Heraeus School on “QCD — Old Challenges and New Opportunities”, September 2017)
• “Monte Carlo — the Quest for Precision” (Higgs Days Santander, September 2017)
• “DGLAP @ NLO in Showers” (HiggsTools meeting, Torino, May 2017)
• “Precision Simulations for LHC physics and beyond” (Seminar, Tsukuba, March 2017)
• “Quest for Precision in Simulations for the LHC” (CERN TH Colloquium, CERN, November 2016)

I also gave a fun talk in the department on the status of particle physics (or, better, my perception of it). I guess it is still somewhat interesting and amusing

• “Complexity to Simplicity and Back” (Durham, September 2017)

JUNE

• “Data, Models, and Reality” (Data Science Colloquium, Victoria University, Wellington, December 2023)
• “Introducing JUNE: an open-source epidemiological simulation” (WHO Impact Modelling Sub-Group, Virtual, May 2022)
• “JUNE – open-source individual-based epidemics model” (DESY Data Science Colloquium, April 2021)

University Teaching

Current lectures in Durham

• Relativistic Quantum Mechanics (undergraduate course, Michaelmas terms 2019-, with revision lecture)

Past lectures in Durham

• Numerical Methods (postgraduate course, Epiphany terms 2017 & 2018)
• QCD (postgraduate course, Epiphany terms 2015-2016)
• Theoretical Physics 2B – Quantum Mechanics, for second year students (Epiphany terms 2011-2014)
• Standard Model (postgraduate course, Michaelmas terms 2007-2009, with Problems)
• Simulations in High-Energy Physics (postgraduate course, Easter terms 2007-2010)
• Computational Physics, for second year students (Michaelmas term 2008, epiphany term 2010)
• Introduction to Particle Physics (Epiphany terms 2008-2010 & 2012)
• Maths, Part IB, for second year students (Michaelmas terms 2006-2009 with Example classes)

Past lectures (in Dresden)

• Quantum Field Theory (summer term 2004, winter term 2005/6, with Example classes and more example classes)
• Gauge Field Theory (winter term 2003/4, with Example classes)
• Quantum Mechanics for High-School Teacher students (summer term 2006, with Example classes)
• Relativistic Physics for High-School Teacher students (summer term 2006, with Example classes)
• Electrodynamics for High-School Teacher students (winter term 2004/5, with Example classes)
• Symmetries in Quantum Mechanics (winter term 2000/1)
• Quarks and Leptons (together with H.Lacker, summer term 2005)
• Computer Methods for Physics students (summer term 2002)

Other activities

Saturday Morning Science
In 2015 I introduced “Saturday Morning Physics”, a series of 6-8 lectures for the general public. In 2018, we promoted this to Saturday Morning Science, a series of 22 lectures that cover research interests from all departments in the faculty of Sciences.
Outreach lecture (last)

• “Particle Physics at the LHC” (given at Ripon Grammar School, March 2014, 2015, 2016)