Programme Synopsis

Quantum field theory (QFT) provides a universal language for describing many facets of nature, [and] in particular the Standard Model of particle physics. A key part of this theory is Quantum Chromodynamics (QCD), the SU(3) gauge theory of the strong interactions between quarks and gluons. It describes a plethora of interesting emergent phenomena, and remains the most actively studied QFT. Computations in QCD are difficult: while its coupling constant is small at very high energies, allowing for the perturbative description of hard parton collisions, the theory becomes non-perturbative at low energies, where important phenomena occur, such as the confinement of quarks and gluons into observable hadronic bound states like the proton. One important aspect for studying the frontiers of QFT is to explore the dynamics and rich phenomenology of collisions at a proton-proton collider, like the Large Hadron Collider (LHC), which simultaneously probe over two orders of magnitude in length scales. The interplay of these different length scales is responsible for many important features, such as the formation and the properties of jets, the dependence of observable quantities on the fundamental parameters of the Standard Model, and considerably complicates the task of producing precise theoretical predictions. 

The challenging environment of the LHC has initiated a multitude of theoretical developments in the past years. Factorization allows us to efficiently separate dynamical processes governed by separated energy scales, to define field theory quantities that are universal for different processes and to sum up large logarithmic corrections to all orders. Fixed-order perturbative computations of hard scattering amplitudes have reached the NNLO and beyond precision level and are complemented by insights into the all-order structure of perturbation theory and soft and collinear singularities. Effective field theory methods allow for coherent formulations and development of factorized cross sections at the operator level, and enable the study of the limits of factorization as well as subleading power effects. The conceptual development of Monte Carlo event generators, parton shower algorithms and parton branching methods at the amplitude level and beyond leading order are acquiring increasing importance to reliably model the final states at the LHC. They open up the possibility to connect analytic approaches to resummation and cutting-edge development of event generators. Furthermore, theoretical predictions for many crucial processes measured at the LHC, involving the Higgs boson, heavy quarks, electroweak gauge bosons and possibly New Physics effects are continuously improved, and eventually electroweak and QED corrections have to be accounted for in experimental analyses. Progress on many of these theoretical directions will also have a direct impact on the ongoing experimental collider program. In particular, the forthcoming Run 3 of the LHC will provide a vast amount of data to test new theoretical predictions.

The purpose of the workshop is to bring together internationally recognized experts and young researchers at the interface of QFT and collider physics phenomenology. We like to support exchange and collaboration of groups, working on connected directions but using different approaches, to foster new developments and insights into many interesting questions and to contribute towards new developments.

Participants and code of conduct

A list of participants is available here. We ask all participants to respect our code of conduct.

Topics and Structure of the Workshop

The workshop lasts for 5 weeks and each week roughly focuses on one of five focus topics. The tentative schedule is as follows.

July 31 - August 4: Finite-Mass and Electroweak Effects in Gauge Theories  

The week focuses on extending modern QCD factorization techniques to massive and unstable particles and to account for electroweak and QED corrections using different approaches. 

August 7 - 11: Singularity Structure of Quantum Field Theory Beyond the Leading Power

The week focuses on investigating the structure of quantum field theory in singular limits and to explore new universal structures.

August 14 - 18: Factorization Violation and the Space of Universal Functions

The week focuses on exploring the limits of the factorization paradigm, as well as strengthening the mathematical foundations on which it is based.

August 21 - 25: Simulation of the All Order Structure of Scattering Amplitudes

The week focuses on developing new simulation methods for QCD scattering amplitudes to improve the accuracy of theory predictions and event simulations.

August 28 - September 1: Multi-Variable Techniques for All Order Resummations in QFT

The week focuses on investigating multi-variable techniques as a means to probe the rich nature of jet dynamics.