Computation of D-brane instanton induced superpotential couplings

• Verfasst von: Cvetič, Mirjam [VerfasserIn]
• Verfasst von: Richter, Robert [VerfasserIn]
• Verfasst von: Weigand, Timo [VerfasserIn]
• Titel: Computation of D-brane instanton induced superpotential couplings
• Titelzusatz: Majorana masses from string theory
• Verf.angabe: Mirjam Cvetic, Robert Richter and Timo Weigand
• Fussnoten: Gesehen am 09.01.2018
• Titel Quelle: Enthalten in: De.arxiv.org
• Jahr Quelle: 2007
• Band/Heft Quelle: (2007) Artikel-Nummer 0703028, 33 Seiten
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1566966906

Abstract

We perform a detailed conformal field theory analysis of D2-brane instanton effects in four-dimensional type IIA string vacua with intersecting D6-branes. In particular, we explicitly compute instanton induced fermion two-point couplings which play the role of perturbatively forbidden Majorana mass terms for right-handed neutrinos or MSSM mu-terms. These results can readily be extended to higher-dimensional operators. In concrete realizations of such non-perturbative effects, the Euclidean D2-brane has to wrap a rigid, supersymmetric cycle with strong constraints on the zero mode structure. Their implications for Type IIA compactifications on the T^6/(Z_2 x Z_2) orientifold with discrete torsion are analyzed. We also construct a local supersymmetric GUT-like model allowing for a class of Euclidean D2-branes whose fermionic zero modes meet all the constraints for generating Majorana masses in the phenomenologically allowed regime. Together with perturbatively realized Dirac masses, these non-perturbative couplings give rise to the see-saw mechanism.