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

Problems with the MSSM : mu & proton decay

This paper describes a set of discrete R symmetries which can be used to define the minimal supersymmetric standard model or singlet extensions of it.Comment: Contribution to KMI Inauguration Conference "Quest for the Origin of Particles and the Universe" (KMIIN), 24-26 Nov. 2011, KMI, Nagoya Universit

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

Neutrino Masses and SO(10) SUSY GUTs

In this talk I discuss the qualitative features of an SO(10) SUSY GUT with an SU(2)x U(1)$^n$ family symmetry. I then describe the global fit of this theory to precision electroweak data [including charged fermion masses and mixing angles]. Finally, the predictions of the model for neutrino masses and mixing are discussed. The most predictive version of the model naturally fits atmospheric neutrino data with maximal $\nu_\mu \longrightarrow \nu_\tau$ oscillations and solar neutrino data with small mixing angle MSW $\nu_e \longrightarrow \nu_{sterile}$ oscillations.Comment: 5 pages, talk presented at NOW2000, Otranto, Italy, Sept. 2000 on work in collaboration with T. Blazek and K. Tob