Professor Watson’s research lies at the interface between particle physics and cosmology, with an emphasis on physics beyond the standard model. As the primordial universe expanded and cooled it passed through a number of transient phases. The behavior of the particles and fields during these transitions resulted in signatures, which allow us to experimentally probe the underlying particle theory. For energies near and below the scale of electroweak symmetry breaking, these cosmological signatures can be combined with particle collider experiments, such as the upcoming Large Hadron Collider (LHC) experiment at CERN, and together they can be used to constrain both cosmological model building and fundamental particle theory. At very high energies, important transitions such as cosmological inflation can give rise to signatures revealing the nature of the earliest moments of the nascent universe. One primary focus of Professor Watson’s research has been in establishing a connection between observations today (such as temperature variations in the cosmic microwave background) with the behavior of particles and fields in the very early universe. In this way, it may be possible with upcoming experiments to probe and test our ideas about quantum theories of gravity -- such as string theory.

Conundrums such as baryon asymmetry, the strong CP problem, neutrino masses, and more conceptual issues, such as naturalness and hierarchies, continue to suggest particle physics beyond the standard model. The current observational status of our universe is that it is comprised of nearly three quarters dark energy driving a period of cosmic acceleration, and the remaining quarter primarily cold dark matter (CDM) – elusive particles which are most likely linked to the scale of new physics. Professor Watson’s research is also focused on exploring and addressing these outstanding issues, by utilizing the intimate connection between cosmology and particle physics.

Dark Matter and LHC: What is the Connection, (G. Kane, S. Watson), Mod. Phys. Lett. A, Vol. 23, No. 26, arXiv:0807.2244 [hep-ph] (2008)

Neutralino Dark Matter from Indirect Detection Revisited, (P Grajek, G. Kane, D. J. Phalen, A. Pierce, S. Watson), arXiv:0807.1508 [hep-ph] (2008)

Non-thermal Dark Matter and the Moduli Problem in String Frameworks, (B. S. Acharya, P. Kumar, K. Bobkov, G. Kane, J. Shao, S. Watson), JHEP 0806:064, arXiv:0804.0863 [hep-ph] (2008).

Geometric Precipices in String Cosmology, (N. Kaloper, S. Watson), Phys. Rev. D77:066002, arXiv:0712.1820 [hep-th] (2008)

Cosmological Moduli Dynamics, (B. Greene, S. Judes, J. Levin, S. Watson, A. Weltman), JHEP 0707:060, hep-th/0702220 (2007)

Inflation without Inflaton(s), (S. Watson, M. J. Perry, G. L. Kane, F. C. Adams), JCAP 0711:017, hep-th/0610054 (2007)

String Gas Cosmology, (T. Battefeld, S. Watson), Rev.Mod.Phys. 78:435-454, hep-th/0510022 (2006)

Moduli Stabilization with the String Higgs Effect, (S. Watson), Phys.Rev.D70:066005, hep-th/0404177 (2004)

Stabilization of Extra Dimensions at Tree Level, (S. Watson, R. Brandenberger), JCAP 0311:008, hep-th/0307044 (2003)