Julian Heeck

Postdoc in the research group in Theoretical Physics (Service de Physique Théorique) at the Université Libre de Bruxelles (ULB), Belgium.
Supported by the F.R.S.-FNRS as a Chargé de Recherches.

Previously postdoc in Dr. Werner Rodejohann's research group MANITOP, part of the Lindner division Particle and Astroparticle Physics at the Max-Planck-Institut für Kernphysik (MPIK) in Heidelberg, Germany.
Alumni of the International Max Planck Research School for Precision Tests of Fundamental Symmetries (IMPRS-PTFS).





Julian Heeck
Service de Physique Théorique, CP225
Université Libre de Bruxelles
Boulevard du Triomphe (Campus de la Plaine)
1050 Bruxelles

Office: 2.N.7.216
Phone: +32 2 650 55 75
Email: julian.heeck [at] ulb.ac.be

Research interests:

  • Neutrino physics
  • Additional gauge symmetries
  • Dark matter
  • Leptogenesis
  • Sterile neutrinos
  • Flavor physics
  • Rare decays
  • ...

Publications and preprints:

A full list can be found at INSPIRE, arXiv, NASA ADS or Scopus.

Conferences, schools, talks, and proceedings:


PhD thesis:

    Neutrinos and Abelian Gauge Symmetries [pdf],
    Heidelberg University and Max-Planck-Institut für Kernphysik (MPIK) in Heidelberg, May 2014.


    We study the intimate connection between neutrinos and simple abelian gauge symmetries U(1), starting from the observation that the full global symmetry group of the Standard Model, G = U(1)BL × U(1)LeLμ × U(1)LμLτ, can be promoted to a local symmetry group by introducing three right-handed neutrinos—automatically making neutrinos massive. The unflavored part U(1)BL is linked to the Dirac vs. Majorana nature of neutrinos; we discuss the B L landscape—including lepton-number-violating Dirac neutrinos—and implications for neutrinos, the baryon asymmetry, and experiments. Flavored subgroups U(1)G can shed light on the peculiar leptonic mixing pattern and mass ordering; we show how normal, inverted, and quasi-degenerate mass hierarchy can arise from a U(1)in a simple and testable manner. We furthermore present all U(1)G that can enforce viable texture zeros in the neutrino mass matrices. Beyond G, symmetries U(1)DM in the dark matter sector can give rise to naturally light sterile neutrinos, which provide a new portal between visible and dark sector, and also resolve some longstanding anomalies in neutrino experiments. Further topics under consideration are the mixing of vector bosons with the Z boson, as well as the Stückelberg mechanism. The latter raises the question why the photon should be massless—or stable for that matter!