I.F.T.

Almuerzo-Seminario

(Lunch seminar)

Oct 3rd 2000, 15:30 p.m.

Type IIB Orientfolds and non-BPS Branes

Angel Uranga

(CERN)

We describe the construction of orientifolds of type IIB string compactifications, with supersymmetric closed string sector but non-supersymmetric open string sector. The latter arises because cancellation of tadpoels is achieved by the introduction of non-BPS configurations of D-branes. The resulting models are non-supersymmetric, but tachyon-free, and stable against decay to supersymmetric configurations. The models can suffer diverse phase transitions (in which the non-BPS configuration of branes changes drastically) which we describe in detail in a concrete example.

Where: Modulo C-XVI, 3rd floor, Facultad de Ciencias U.A.M., C.U. Cantoblanco, 28049-Madrid