Disputation: Vanja Morisbak

Doctoral candidate Vanja Morisbak at the Department of Physics, Faculty of Mathematics and Natural Sciences, is defending the thesis 

         "Searching for new forces of Nature

  New neutral gauge bosons in dimuon final states with                            the ATLAS detector at the LHC"

for the degree of Philosophiae Doctor.

portrait of the candidate

The PhD defence and trial lecture are fully digital and streamed using Zoom.  The chair of the defence will moderate the disputation.

Ex auditorio questions: the chair of the defence will invite the audience to ask ex auditorio questions either written or oral. This can be requested by clicking 'Participants' and then choose 'Raise hand'. 

Trial lecture

"The search for gravitational waves: Motivation and results"




Main research findings

The smallest parts of the world that we live in are described mathematically by the hugely successful Standard Model of Particle Physics. Nevertheless, during the last several decades researchers within physics have observed many phenomena that cannot be explained within this framework. Among the most noticeable observations are the fact that the Standard Model only describes 5% of the energy content of the whole Universe. There is a worldwide search ongoing for a more complete understanding, and the analysis described in this thesis is a small part of this comprehensive work.

Some theories beyond the Standard Model include new, electrically neutral, massive, force carrying particles called Z'. These might be produced at the Large Hadron Collider (LHC) at CERN in the energetic collisions between protons. Using data from the ATLAS detector, one of the four main experiments at the LHC, I have searched for Z' particles in final states with two muons (elementary particles), without finding it. In the absence of a detected signal, I set limits on the lowest possible mass of the Z' in several theories, between 3.8 and 4.4 TeV. My results are comparable to the recent published results from the ATLAS Collaboration and the CMS Collaboration.

many Z's


Contact information to Department: Line Trosterud Resvold

Published Dec. 30, 2020 10:59 AM - Last modified Jan. 15, 2021 2:58 PM