Precision searches for new physics with boosted bosons combined

• Applicant: Dr. Andreas Hinzmann
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2016 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 312958277

One of the biggest unresolved questions in physics is why there is a hierarchy of many orders of magnitude between the strength of the forces described by the Standard Model (electroweak and strong) and the gravitational force. A unified description of all forces in a common theory must explain this hierarchy. The data recorded by the CMS experiment at the Large Hadron Collider (LHC) in 2015-2018 at a center-of-mass energies of 13 TeV may finally shed light on this question. Popular new physics scenarios providing an explanation to this question are extra spacial dimensions or a composite Higgs boson, exhibiting a fundamental common signature at the LHC: resonant or non-resonant deformations of the invariant mass spectra for pair production of highly boosted W, Z and Higgs bosons. Their measurement at best possible precision at the TeV-scale is thus of highest importance and is the core goal of this project. The highly boosted W, Z and Higgs bosons, which predominately decay to quark anti-quark pairs, form massive jets of particles in the detector that require complex reconstruction techniques based on jet substructure to identify them, posing a major technical challenge for this project. While the CMS experiment will continue to take data for more than a decade to reduce statistical uncertainties of boson pair production measurements, the two most important areas to gain significantly in sensitivity on a short time scale are the statistical combination of multiple measurements and advancements in the calibration and simulation of jet substructure. In this project, firstly, a cross-experiment interpretation of jet substructure measurements to improve its simulation and gauging of uncertainties is pursued. Secondly, a combination of all CMS measurements of boson pair mass spectra and resonance searches with an advanced calibration and simulation of jet substructure is carried out. By understanding the di-boson mass spectra at the highest energies with a precision never reached before, this project possesses significant potential for discovery of new physics.

• DFG Programme: Independent Junior Research Groups