Department of Physics Papers

Document Type

Journal Article

Date of this Version

9-18-2008

Comments

Suggested Citation:
M. Cvetič and P. Langacker. (2008). "D-instanton generated Dirac neutrino masses." Physical Review D. 78, 066012.

© 2008 The American Physical Society
http://dx.doi.org/10.1103/PhysRevD.78.066012

Abstract

We present a stringy mechanism to generate Dirac neutrino masses by D-instantons in an experimentally relevant mass scale without fine-tuning. Within type IIA string theory with intersecting D6-branes, we spell out specific conditions for the emergence of such couplings and provide a class of supersymmetric local SU(5) grand unified models, based on the Z2 × Z'2 orientifold compactification, where perturbatively absent Dirac neutrino masses can be generated by D2-brane instantons in the experimentally observed mass regime, while Majorana masses remain absent, thus providing an intriguing mechanism for the origin of small neutrino masses due to nonperturbative stringy effects.

Date Posted: 13 January 2011

This document has been peer reviewed.