The 14th edition of QCD@LHC, aiming at fostering discussions and collaboration between experimenters and theorists working on strong interactions at the LHC, will be held in Freiburg, Germany
Topics and conveners:
Talks by invitation only. In case you are interested in giving a talk, please contact the respective conveners.
International Advisory Committee:
Sergey Alekhin (DESY), Johannes Blümlein (DESY), Claude Duhr (Bonn), Keith Ellis (Durham), Thomas Gehrmann (Zürich), Nigel Glover (Durham), Joey Huston (Michigan State), Judith Katzy (DESY), Frank Krauss (Durham), Jean-Philippe Lansberg (Orsay), Fabio Maltoni (Louvain), Michelangelo Mangano (CERN), Zoltan Nagy (DESY), Eram Syed Rizvi (QMUL), Frank Siegert (Dresden), Dominik Stöckinger (Dresden), Zoltan Trocsanyi (Budapest), Doreen Wackeroth (Buffalo), Ciaran Williams (Buffalo),
Local Organizing Committee:
Stefan Dittmaier, Karl Jakobs, Heidi Rzehak, Markus Schumacher, Maximilian Stahlhofen, Christian Weiser, Christina Skorek (secr.), Susanne Trauth (secr.)
Group Photo from the conference
The availability of high-multiplicity multi-loop scattering amplitudes in QCD provides invaluable data for studying the theory under special kinematic configurations. Recent calculations of two-loop full-colour QCD amplitudes for the scattering of five partons have enabled us to explore their high-energy limit, known as Multi-Regge Kinematics (MRK). In this limit, a universal factorisation pattern is expected for the amplitude. However, starting at the next-to-next-to-leading logarithmic order (NNLL), the exchange of multiple reggeons (MR) disrupts this factorisation.
In this talk, I will first review the effective theory that accurately describes the high-energy limit and how it predicts the MR contributions. Once the latter are properly accounted for, the universal factorisation pattern is restored. This restoration allowed us to extract a fundamental ingredient for the factorisation at NNLL: the Lipatov vertex at two-loop order. I will also delve into various technical details of how this calculation was carried out.
I'd like to present the numerical calculation of the Nf-part of the 2-loop 5-point massive virtual amplitudes for qq->ttH production based on arXiv:2402.03301, describing the methods (i.e. sector decomposition), the tools (pySecDec and Ratracer), and the outlook for the remaining work.
We present a lattice QCD calculation of the distribution amplitudes for pseudoscalar mesons, specifically the pion and kaon, as well as for polarized vector mesons, K* and φ, using large momentum effective theory. This study employs the clover fermion action across three ensembles with 2+1+1 flavors of highly improved staggered quarks, as generated by the MILC Collaboration at physical pion mass and lattice spacings of {0.06, 0.09, 0.12} fm. The lattice matrix elements obtained are nonperturbatively renormalized using a recently proposed hybrid scheme with self-renormalization, and they are reliably extrapolated to both the continuum and the infinite momentum limits. We also investigated the systematic uncertainties from various aspects.
Using the recent calculation of GPD moments by the Hadstruc collaboration in the pseudo-distribution formalism, I will present the possibilities and challenges faced in terms of uncertainty. I will notably discuss the questions of the continuum limit, higher twist contamination, perturbative matching and inverse problem reconstruction for the x-dependence.