Deutsches Elektronen-Synchrotron DESY
Notkestraße 85
22607 Hamburg

Universität Hamburg
Institut für Experimentalphysik
Luruper Chaussee 149
22761 Hamburg

Johannes Gutenberg-Universität Mainz
Saarstr. 21
55122 Mainz

The Standard Model of particle physics explains the origin of particle masses via their interaction with the Higgs field. Experimentally most of the Standard Model predictions have been confirmed and only the carrier of the Higgs field, the Higgs boson, remains undiscovered yet. The mass of the Higgs boson can be constrained in the Standard Model indirectly by e.g. precision measurements of electroweak parameters. Among those a precise measurement of the top quark mass is crucial to pin down the prediction for the Higgs mass and will improve the sensitivity to physics beyond the Standard Model. Moreover, after the Higgs discovery the precise knowledge of the top quark mass is needed to test the consistency of the Standard Model with much better precision. At the Large Hadron Collider (LHC) at CERN the high energy proton beams will be brought in collision at a centre of mass energy of 14 TeV aiming the discovery of the Standard Model Higgs and the study of its production. The LHC will also be a top quark factory. The most probable channel for Higgs and top quark production in proton-proton collisions is the interaction between gluons of the colliding protons, the so called gluon-gluon fusion process. On the other hand this process is also the main source of huge backgrounds. The success of the LHC effort in studying the Standard Model and its possible extensions demands a correct description of the processes originating from gluon-gluon fusion. This makes the gluon density distribution in the proton a key issue for LHC physics. The exact knowledge of the gluon density distribution in the proton can be provided by electron-proton scattering experiments at HERA. Recent upgrades in accelerator performance, detector hardware and the event reconstruction at the HERA experiments allows the high precision measurements of the gluon density via photon-gluon fusion processes which was not feasible before to the desired accuracy. In the photon-gluon fusion process the gluon is always directly involved. This is a big advantage of such a process in comparison to measurements of inclusive cross sections in deep inelastic scattering, from which the gluon density is usually determined. As a result of the first years of the project the extracted gluon density will be provided just at the moment where the data of LHC will be available for physics analysis. Predictions for the Higgs and top quark production cross sections will be made. With the first data of LHC available the top quark production cross section will be studied and the top quark mass will be measured.

This project takes part in the interplay of both HERA experiments, theory, and the first analyses of the CMS experiment at LHC in the common effort of the understanding of the Standard Model of high energy physics.

Leader of the Young Investigators Group of Helmholtz:

Dr. Katerina Lipka
Deutsches Elektronen-Synchrotron
Notkestr. 85
22607 Hamburg
Office: 1a/601
Tel.: +49-40-8998-1983
Email: katerina.lipka@desy.de

Host Scientist

Prof. Dr. Joachim Mnich
Deutsches Elektronen-Synchrotron
Notkestr. 85
22607 Hamburg
Tel.: +49-40-8998-1921
Fax: +49-40-8998-4304
Email: joachim.mnich@desy.de

University Partners

Prof. Dr. Robert Klanner
Universität Hamburg
Institut für Experimentalphysik
Luruper Chaussee 149
22761 Hamburg
Office: 68/132
Tel.: +49-40-8998-2558
Email: robert.klanner@desy.de

Prof. Dr. Hubert Spiesberger
Institut für Physik (WA THEP)
Johannes-Gutenberg-Universität
D-55099 Mainz
Staudingerweg 7, 04-124
Tel.:+49-6131-39 23 682
Fax: +49-6131-39 24 611
Email: hspiesb@thep.physik.uni-mainz.de

Privat Dozentin Dr. Karin Daum
Universität Wuppertal
Standort DESY in Hamburg
Notkestrasse 85
D-22607 Hamburg
Tel.: +49-40-8998 2364
Email: karin.daum@desy.de