Department of Physics, Engineering Physics & Astronomy

Department of Physics, Engineering Physics & Astronomy
Department of Physics, Engineering Physics & Astronomy

Departmental Colloquium - The Quantum and the Cosmos: the Quest for the Origin of Ordinary and Dark Matter

Stefano Profumo,
University of California, Santa Cruz

Thursday May 7, 2015
10:00 AM in Theatre A

Abstract:

Two mysteries loom at the interface of cosmology and particle physics: why is there more matter than antimatter? and what is the dark matter that dominates the matter content of the universe? In my colloquium, I will discuss progress and directions in formulating experimentally testable theories for the matter-antimatter asymmetry (baryogenesis) and for the nature of the dark matter. 
 
I will present a class of models known as electroweak baryogenesis, where the matter-antimatter asymmetry is generated at the phase transition, in the very early universe, when the Higgs acquires a non-zero vacuum expectation value. Electroweak baryogenesis is being tested with a variety of probes, from primordial gravitational waves, to precision measurements of the permanent electric dipole moment of elementary particles, to the Large Hadron Collider. 
 
I will then outline the current state of the art of searches for the fundamental, particle nature of the cosmological dark matter. I will describe how several intriguing signals, especially from astronomical observations and cosmic-ray data, are affected by subtle astrophysical backgrounds, but might reveal the first hints about the nature of the dark matter.