Deutsches Elektronen-Synchrotron DESY
Notkestraße 85
22607 Hamburg

Universität Hamburg
Institute of Experimental Physics
Luruper Chaussee 149
22761, Hamburg

Karlsruher Institut für Technologie (KIT)
Institut für Experimentelle Kernphysik (IEKP)
Hermann-von-Helmholtz-Platz 1
76344 Eggenstein-Leopoldshafen

The Standard Model (SM) gives a coherent and complete description of the elementary constituents and – apart from gravity – interactions of matter, and has been extraordinarily successful in explaining practically all experimental observations in particle physics. Within the SM, the top quark plays a very special role in the description of the structure of matter and interactions. Being the heaviest fundamental particle, it offers a unique possibility to study bare quark properties and investigate Higgs boson couplings. Together with the Higgsboson mass, the top-quark mass provides insight in the stability of the electroweak vacuum, connected to the ultimate fate of the Universe. Moreover, many scenarios of physics phenomena beyond the Standard Model (BSM) expect the top quark to couple to new particles. Experimentally, Standard Model top-quark processes are a dominant background to many searches for BSM physics. The top quark is, therefore, a key to constraining SM parameters, measuring Higgs boson properties, and discovering a broad range of new
physics phenomena. In this project, advanced studies of the top-quark properties will be performed within the CMS experiment at the Large Hadron Collider (LHC) accelerator. In the light of the recent discovery of a Higgs boson at the LHC, the main objective of this project is the investigation of top-quark pair production in association with a Higgs boson to ascertain its consistency with the SM Higgs boson. Further objectives are precision measurements of differential topquark- pair production cross sections towards constraining theoretical models and searching for novel physics phenomena. Ultimate measurement precision for stringent tests of the SM will be achieved through the combination of results of the ATLAS and CMS experiments at the LHC. With its engagement in both experiments, as well as in high-energy phenomenology, DESY offers a distinguished environment for this project. Since the start of the LHC in 2009, the CMS experiment has been operated very successfully and is scheduled for operation far beyond 2020. Particularly, the excellent performance of the CMS tracking system is an essential prerequisite for the successful continuation of topquark-related measurements. With the LHC luminosity upgrade planned for the beginning of the next decade, the present tracking system will have reached the end of its operational life
span mainly due to the damage caused by radiation, and a new enhanced system must be built which can withstand the aggravated environment. Further objectives of this project will be the development of novel design options for tracker sensor modules, with particular focus on the experimental qualification of innovative high-performance materials. The project group will participate in building and qualifying first functional module prototypes, profiting from the DESY expertise and engineering support.

Leader of the Young Investigators Group of Helmholtz:

Dr. María Aldaya Martín
Deutsches Elektronen-Synchrotron DESY
Notkestr. 85
22607 Hamburg

Phone: +49 40 8998-3858
Email: maria.aldaya@desy.de

University partner

Prof. Dr. Erika Garutti
Universität Hamburg
Institute of Experimental Physics
Luruper Chaussee 149
22761, Hamburg

Prof. Dr. Ulrich Husemann
Karlsruher Institut für Technologie (KIT)
Institut für Experimentelle Kernphysik (IEKP)
Hermann-von-Helmholtz-Platz 1
76344 Eggenstein-Leopoldshafen