Forschergruppe5.jpg DFG Research Unit 2239: New Physics at the LHC

The Large Hadron Collider (LHC) at CERN is the flagship research facility of particle physics for the next decade. After the discovery of a Higgs particle in the first phase of the LHC in 2012, the key scientific goal for the second phase, starting in 2015, is to search for and explore physics beyond the Standard Model (SM). The existence of new physics at the Tera-electronvolt (TeV) scale, i.e. in reach of the LHC, is motivated by two fundamental questions left unanswered by the SM: the hierarchy problem and the nature of dark matter. The hierarchy problem refers to the instability of the Higgs mass at the electroweak scale under quantum fluctuations originating from high-scale physics. It can be solved, for example, through new TeV -scale particles partnering the SM top quark. Dark matter, on the other hand, is explained naturally by stable, weakly interacting particles with masses near the TeV scale. Such particles are predicted in many extensions of the SM, which attempt to solve the hierarchy problem, like supersymmetry or models with extra space dimensions. At the LHC, new physics can be searched for either directly, for example in signatures with a transverse momentum imbalance caused by escaping dark matter particles, or through precision studies which attempt to establish deviations from the Standard Model in a global theoretical analysis of all existing experimental observables, including in particular the Higgs sector.

In the Research Unit “New Physics at the LHC” we pursue theoretical calculations and analyses of new physics scenarios at the LHC which address the hierarchy problem, the origin of dark matter, or both. They comprise, in particular, precision calculations for the production and decay of new particles, the exploration of the top-Higgs sector and models of dark matter, a systematic study of top-partner and dark matter production and detection at the LHC, and global fits of Higgs properties and new physics models. These theoretical analyses shall provide the basis for the interpretation of new physics searches during the second phase of the LHC, and are crucial in order to fully exploit its potential.

Research Program


The goal of the Research Unit “New Physics at the LHC” is to provide theoretical calculations and numerical tools for TeV -scale new physics searches and exploration at the LHC, motivated by the hierarchy problem, the search for the origin of dark matter, or both. We pursue precision calculations and the developments of tools, explore the top-Higgs sector and models of dark matter, and test new physics scenarios through global fits. Specifically, we
  • A develop automated tools for calculating the production and decay of new particles at the LHC, including next-to-leading order QCD corrections and the resummation of large logarithmic corrections;
  • B explore the top-Higgs sector in strongly or weakly interacting theories and in multiscale models, and analyze their LHC phenomenology in QCD signatures and through simplified models;
  • C probe the nature of dark matter at the LHC in a model-independent way based on simplified models with tree- and loop-level couplings, taking into account the most important QCD effects, and study the interplay of LHC searches and other probes of dark matter;
  • D develop theoretical methods and tools to improve global fits of Higgs properties and more generic new physics models, like those performed within the SFITTER and FITTINO collaborations.

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Members


RWTH Aachen University

University of Bonn

Heidelberg University

Johannes Gutenberg University Mainz

Events


Publications