TRR 257:  P3H: Particle Physics Phenomenology after the Higgs Discovery

• Subject Area: Physics
• Term: since 2019
• Website: Homepage
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 396021762

The CRC “Particle Physics Phenomenology after the Higgs Discovery” (P3H) strives to advance the understanding of Nature at its most fundamental level through the study of elementary particles and their interactions. The discovery of the Higgs Boson in 2012 at the Large Hadron Collider (LHC) at CERN completed the so-called Standard Model (SM) of particle physics and therefore marked the beginning of a new era. While current data obtained at high-energy colliders seem to be in almost perfect agreement with the SM, an increasing number of “anomalies'' is found in flavour- and other low-energy experiments. Furthermore, cosmological and astrophysical observations point to the existence of dark matter, dark energy and sources of charge-parity (CP) violation the SM cannot explain. As possible extensions of the SM in the current landscape of particle physics are not guided by the direct detection of new particles, a push towards indirect methods in searches for physics beyond the SM (BSM) is needed, as well as fortified connections between flavour physics and collider physics at the energy frontier. The CRC P3H is a response to the paradigm shift towards precision physics as the driving force for indirect searches of BSM physics. Its long-term research goal is the development of a comprehensive framework to search for, discover and explore BSM physics in a situation where high precision theoretical predictions, to be compared to equally precise data, play a vital role on the way to new discoveries. The research areas include Higgs physics, the physics of top quarks, electroweak gauge bosons and jets, and flavour physics. The different focus areas will be explored with various approaches: BSM effects will be studied via Effective Field Theories as well as through explicit models, machine learning tools will be developed for largely model-independent anomaly searches, and cutting-edge perturbative corrections will be included in the predictions for key processes at the LHC and at flavour factories. World-leading experts in collider- and flavour physics join their forces under the umbrella of the CRC, creating synergies in the development of methodologies and in the creation of new ideas how to get maximal information about the underlying - possibly new - particle dynamics from the upcoming highquality data. Therefore, the Collaborative Research Center P3H is in the position to consolidate and increase its major impact on the international effort to achieve an unprecedented level of precision in particle physics, allowing to identify even small deviations from the SM as New Physics.

• DFG Programme: CRC/Transregios

Current projects

• A1 - Quark-mass effects in Higgs-boson production in gluon fusion (Project Heads Czakon, Michal ;  Harlander, Robert )
• A1 - Higgs boson physics with higher-order corrections and anomalous couplings (Project Heads Harlander, Robert ;  Heinrich, Gudrun ;  Melnikov, Kirill )
• A1 - Higher order QCD corrections to Higgs boson production in weak boson fusion (Project Head Melnikov, Kirill )
• A2 - The effective electroweak Lagrangian in the light of the LHC (Project Heads Kilian, Wolfgang ;  Krämer, Michael ;  Plehn, Tilman )
• A2 - Multi-boson physics at the LHC (Project Heads Butter, Anja ;  Heinrich, Gudrun ;  Kilian, Wolfgang ;  Zeppenfeld, Dieter )
• A3 - Extended Higgs sectors at the LHC (Project Heads Mühlleitner, Milada Margarete ;  Plehn, Tilman )
• A3 - Precision predictions for Higgs boson properties as a probe for New Physics (Project Heads Mühlleitner, Milada Margarete ;  Steinhauser, Matthias )
• B1 - N3LO QCD predictions for production cross sections of colourless systems in association with a resolved jet (Project Heads Bell, Guido ;  Czakon, Michal ;  Melnikov, Kirill )
• B1 - Precision top-quark physics at the LHC (Project Heads Czakon, Michal ;  Heinrich, Gudrun ;  Worek, Malgorzata )
• B1 - Power corrections in collider processes (Project Heads Bell, Guido ;  Czakon, Michal ;  Melnikov, Kirill )
• B2 - Automated Calculations in Soft-Collinear Effective Theory (Project Head Bell, Guido )
• B2 - Anomalous couplings in the top quark sector (Project Heads Heinrich, Gudrun ;  Worek, Malgorzata )
• B3 - Dark sectors at colliders and flavour experiments (Project Heads Kahlhoefer, Felix ;  Krämer, Michael ;  Plehn, Tilman )
• B3 - Anomaly searches in jet physics (Project Heads Krämer, Michael ;  Plehn, Tilman )
• C1 - Inclusive semi-leptonic, rare and radiative decays of B-mesons (Project Heads Huber, Tobias ;  Mannel, Thomas ;  Steinhauser, Matthias )
• C1 - B-Bbar-mixing, CP-violation and lifetimes (Project Heads Lenz, Alexander ;  Nierste, Ulrich ;  Steinhauser, Matthias )
• C1 - Non-perturbative matrix elements for B-mixing and Lifetimes (Project Heads Harlander, Robert ;  Lenz, Alexander ;  Nierste, Ulrich )
• C2 - Hadronic matrix elements and exclusive semi-leptonic decays (Project Heads Feldmann, Thorsten ;  Mannel, Thomas )
• C2 - Exclusive non-leptonic and rare b-quark decay (Project Heads Bell, Guido ;  Feldmann, Thorsten ;  Huber, Tobias )
• C3 - New sources of flavour violation at high transverse momenta (Project Heads Blanke, Monika ;  Krämer, Michael ;  Mühlleitner, Milada Margarete )
• C3 - New Physics models for flavour observables (Project Head Nierste, Ulrich )
• Z - Central Tasks of the Collaborative Research Center (Project Heads Heinrich, Gudrun ;  Melnikov, Kirill )

Completed projects

• B1 - Central jets in vector-boson scattering (Project Head Zeppenfeld, Dieter )
• B1 - Theoretical advances in parton showers (Project Heads Czakon, Michal ;  Gieseke, Stefan )
• B2 - Operator Analysis of New Physics in Top-Quark Observables (Project Head Westhoff, Susanne )

• Applicant Institution: Karlsruher Institut für Technologie
• Co-Applicant Institution: Rheinisch-Westfälische Technische Hochschule Aachen; Universität Siegen
• Participating University: Ruprecht-Karls-Universität Heidelberg
• Spokespersons: Professorin Dr. Gudrun Heinrich, since 1/2023; Professor Dr. Kirill Melnikov, until 12/2022