Nonperturbative flipped SU(5) vacua in heterotic M-theory

por Jose M. Isidro (IFIC)

martes 2 jul. 2002 12:30 → 13:30 Europe/Madrid

Sala Seminarios (Dpto. de Física Teórica (UVEG))

There is experimental support for the embedding of the Standard Model fermions in the chiral ${\bf 16}$ $SO(10)$ representation. Such an embedding is afforded by the realistic free fermionic heterotic--string models. In this paper we advance the study of these string models toward a non--perturbative analysis by generalizing the work of Donagi, Pantev, Ovrut and Waldram from the case of $G=SU(2n+1)$ to $G=SU(2n)$ stable holomorphic vector bundles on elliptically fibered Calabi--Yau manifolds with fundamental group ${\bf Z}_2$. We demonstrate existence of $G=SU(4)$ solutions with three generations and $SO(10)$ observable gauge group over Hirzebruch base surface, whereas we show that certain classes of del Pezzo base surface do not admit such solutions. The $SO(10)$ symmetry is broken to $SU(5)\times U(1)$ by Wilson lines. The overlap with the realistic free fermionic heterotic--string models is discussed.