Three Family Models from the Heterotic String

In this talk I outline work done in collaboration with R.J. Zhang and T. Kobayashi. We show how to construct the equivalent of three family orbifold GUTs in five dimensions from the heterotic string. I focus on one particular model with E(6) gauge symmetry in 5D, the third family and Higgs doublet coming from the 5D bulk and the first two families living on 4D SO(10) branes. Note the E(6) gauge symmetry is broken to Pati-Salam in 4D which subsequently breaks to the Standard Model gauge symmetry via the Higgs mechanism. The model has two flaws, one fatal and one perhaps only unaesthetic. The model has a small set of vector-like exotics with fractional electromagnetic charge. Unfortunately not all of these states obtain mass at the compactification scale. This flaw is fatal. The second problem is R parity violating interactions. These problems may be avoidable in alternate orbifold compactification schemes. It is these problems which we discuss in this talk.Comment: 5 pages, 6 figures, plenary talk given at PASCOS 2005, May 30 - June 4, Gyeongju, Kore

SO(10) Yukawa Unification after the First Run of the LHC

In this talk we discuss SO(10) Yukawa unification and its ramifications for phenomenology. The initial constraints come from fitting the top, bottom and tau masses, requiring large $\tan\beta \sim 50$ and particular values for soft SUSY breaking parameters. We perform a global $\chi^2$ analysis, fitting the recently observed `Higgs' with mass of order 125 GeV in addition to fermion masses and mixing angles and several flavor violating observables. We discuss two distinct GUT scale boundary conditions for soft SUSY breaking masses. In both cases we have a universal cubic scalar parameter, $A_0$. In the first case we consider universal gaugino masses, and universal scalar masses, $m_{16}$, for squarks and sleptons; while in the latter case we have non-universal gaugino masses and either universal scalar masses, $m_{16}$, for squarks and sleptons or D-term splitting of scalar masses. We discuss the spectrum of SUSY particle masses and consequences for the LHC.Comment: 12 pages, talk presented at the VIIth International Conference on Interconnections between Particle Physics and Cosmology and CETUP* 2013, Lead, S

String Model Building

In this talk I review some recent progress in heterotic and F theory model building. I then consider work in progress attempting to find the F theory dual to a class of heterotic orbifold models which come quite close to the MSSM.Comment: 11 pages, 10 figures, plenary talk submitted for the proceedings of SUSY 2009, June 5 - 10, Northeastern University, Boston, M

Higgs and SUSY Particle Predictions from SO(10) Yukawa Unification

In this talk we assume SO(10) boundary conditions at the GUT scale, including unification for the third generation Yukawa couplings $\lambda_t = \lambda_b = \lambda_\tau$. We find that this assumption is only consistent with the low energy data in a narrow region of soft SUSY breaking parameter space. We discuss the consequences of this result for Higgs and SUSY searches.Comment: 8 pages, talk given at the 1st InternationalConference on String Phenomenology, Oxford, UK, July 6 - 11, 200