I.F.T.
Almuerzo-Seminario
(Lunch seminar)
April 28th 1998, 1:00 p.m.
A Chiral D=4, N=1 String Vacuum with a Finite Low
Energy Effective Field Theory
Luis Ibáñez
(I.F.T./U.A.M.)
Supersymmetric N=1, D=4 string vacua are known to be finite in
perturbation theory. However, the effective low energy D=4, N=1 field
theory lagrangian does not yield in general finite theories. In this
note we present the first (to our knowledge) such an example. It may
be constructed in three dual ways: i) as a $Z_3$, SO(32) heterotic
orbifold; ii) as a Type -IIB, $Z_3$ orientifold with only ninebranes
and a Wilson line or iii) as a Type-IIB, $Z_6$ orientifold with only
fivebranes. The gauge group is $SU(4)^3$ with three chiral
generations. Although chiral, a subsector of the model is continuosly
connected to a model with global N=4 supersymmetry. From the $Z_6$,
Type IIB orientifold point of view the above connection may be
understood as a transition of four dynamical fivebranes from a fixed
point to the bulk. The N=1 model is thus also expected to be
S-dual. We also remark that, using the untwisted dilaton and moduli
fields of these constructions as spurion fields, yields soft
SUSY-breaking terms which preserve finiteness even for N=0.
The almuerzo-seminario is
intended to be an informal seminar and an open forum for discussion.
You are wellcome to bring your own
bocata (sandwich), or coffee or tea.
Where: Modulo C-XVI, 3rd floor,
Facultad de Ciencias U.A.M., C.U. Cantoblanco, 28049-Madrid
To get more information about this seminar e-mail
Tomás Ortín
or phone +34-1-397-8546
Last modified: Fri Mar 27 17:04:08 WET 1998