F SU (5)
Abstract
We construct three flipped SU (5) × U(_{1)X} models from Ftheory, and consider two such models from free fermionic string model building. To achieve the decoupling scenario in Ftheory models and the stringscale gauge coupling unification in free fermionic models, we introduce vectorlike particles at the TeV scale that can be observed at the Large Hadron Collider. We study gauge coupling unification, and find that proton decay is within the reach of the future HyperKamiokande experiment. In these models, the doublettriplet splitting problem and monopole problem can be solved, the neutrino masses and mixings can be explained via the double seesaw or seesaw mechanism, the observed baryon asymmetry can be obtained through leptogenesis, the hybrid inflation can be realized, and the correct cosmic primordial density fluctuations can be generated.
 Publication:

Physics Letters B
 Pub Date:
 June 2009
 DOI:
 10.1016/j.physletb.2009.05.012
 arXiv:
 arXiv:0811.2807
 Bibcode:
 2009PhLB..677..322J
 Keywords:

 11.10.Kk;
 11.25.Mj;
 11.25.w;
 12.60.Jv;
 Field theories in dimensions other than four;
 Compactification and fourdimensional models;
 Strings and branes;
 Supersymmetric models;
 High Energy Physics  Theory;
 High Energy Physics  Phenomenology
 EPrint:
 RevTex4, 5 pages, 1 figure, 2 tables, typos corrected, to appear in PLB