University of Pittsburgh

Ayres Freitas

Associate Professor
University of Pittsburgh
403 Allen Hall

(412) 624-9060
(412) 624-9163 (fax)
Research: Particle Physics
Personal Web site: Research and Teaching Website

Grad Students

Stefan Schader Kell


Susanne Westhoff


My research mostly deals with the phenomenology of new particles and interactions at colliders. The breaking of the electroweak symmetry and the stabilization of the electroweak scale has inspired new ideas like the Higgs mechanism, supersymmetry, extra dimensions, technicolor and little Higgs models. I am studying how these models can be constrained by existing precision data and possibly could be discovered at future experiments, most notably at the Large Hadron Collider. Of special interest to me are precision analyses that would allow to reconstruct the underlying framework of a model from experimental data. On the technical side, this involves development of loop calculation techniques and Monte–Carlo tools.  Some of the new physics models quite naturally could explain the origin of ordinary matter and/or dark matter in the universe. This opens up striking connections between collider physics and astrophysics and cosmology.


  • "Precision Measurements of Higgs Couplings: Implications for New Physics Scales," C. Englert, A. Freitas, M. Mühlleitner, T. Plehn, M. Rauch, M. Spira, K. Walz,invited review to appear in J. Phys. G.
  • "Testing the Muon g-2 Anomaly at the LHC," A. Freitas, J. Lykken, S. Kell, S. Westhoff, JHEP 1405, 145 (2014).
  • "Higher-order electroweak corrections to the partial widths and branching ratios of the Z boson," A. Freitas, JHEP 1404, 070 (2014).
  • "Two-loop fermionic electroweak corrections to the Z-boson width and production rate," A. Freitas,  Phys. Lett. B 730, 50 (2014).
  • "High Energy WW Scattering at the LHC with the Matrix Element Method," A. Freitas and J. S. Gainer, Phys. Rev. D 88, 017302 (2013).


Department of Physics and Astronomy
University of Pittsburgh
100 Allen Hall
3941 O'Hara St
Pittsburgh PA 15260
O: (412) 624-9000 | F: (412) 624-9163

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