Electroweak symmetry breaking at the LHC

• Grant number: 11/10199-3
• Support type: Scholarships abroad - Research
• Effective date (Start): October 03, 2011
• Effective date (End): October 02, 2012
• Field of knowledge: Physical Sciences and Mathematics - Physics - Elementary Particle Physics and Fields
• Principal researcher: Rogério Rosenfeld
• Grantee: Rogério Rosenfeld
• Host: Christophe Grojean
• Home Institution: Instituto de Física Teórica (IFT). Universidade Estadual Paulista (UNESP). Campus de São Paulo. São Paulo , SP, Brazil
• Research place: European Organization for Nuclear Research (CERN), Switzerland

Abstract

The Standard Model (SM) of the electroweak and strong interactions is a great successin describing a large amount of experimental data collected over several decades in many experiments at different energy scales. It has been tested with great precision, and calculations using quantum field theory at higher order in perturbation theory are necessary in order to reach agreement between theory and experiments. However, there are evidences that the SM is incomplete. They come mainly from the possible existence of dark matter, as inferred from several astrophysical observations, and the small but nonzero masses of neutrinos. More importantly, the SM has not yet been probed in one of its most fundamental aspect: the breaking of electroweak symmetry, which makes the electromagnetic and weak interactions so different from each other and generates masses for the particles. At the heart of the breaking of electroweak symmetry is the Higgs mechanism described by the Higgs sector of the SM. It predicts the existence of an elementary scalar particle, the Higgs boson. The search for the Higgs boson is certainly the top priority at the LHC. The Higgs sector of the SM presents serious difficulties associated with the so-called naturalness orhierarchy problem: in the absence of further symmetries it is not possible to mantain in a natural way a hierarchy between two different energy scales, such as the Planck and electroweak scales, without introducing an unnaturally largeamount of fine-tuning in the parameters. There are several models that go beyond the SM andameliorate this problem. An incomplete list comprises supersymmetric extensions, technicolor models, Higgs as a pseudo Nambu-Goldstoneboson and the more recent models with compact extra dimensions (large, universal and warped). The purpose of this Project is to explore models of electroweak symmetry breaking beyond the usual Higgs sector of the SM and study their signatures at the LHC. In most of these models there are new particles and their detection can be a smoking gunfor the physics of the electroweak breaking mechanism. In particular, one of our concerns will be the radion, a particle that arises from the fluctuations of the radius of the extra dimension, that will be studiedin warped models. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BELYAEV, A.; OLIVEIRA, A. C. A.; ROSENFELD, R.; THOMAS, M. C. Multiple Higgs and vector boson production beyond the Standard Model. Journal of High Energy Physics, n. 5 MAY 2013. Web of Science Citations: 3.