Leptonic dynamical Yukawa couplings

Abstract

Journal of High Energy Physics 2013.8 (2013): 069 reproduced by permission of Scuola Internazionale Superiore di Studi Avanzati (SISSA) ; A dynamical origin of the Yukawa couplings is a promising scenario to explain the flavour puzzle. The focus of this letter is set on the role of the neutrino Majorana character: when an O(2)N flavour symmetry acts on the right-handed neutrino sector, the minimum of the scalar potential allows for large mixing angles -in contrast to the simplest quark case- and predicts a maximal Majorana phase. This leads to a strong correlation between neutrino mass hierarchy and mixing pattern. Realistic solutions point to the existence of three heavy right-handed neutrinos ; We acknowledge partial support by European Union FP7 ITN INVISIBLES (Marie Curie Actions, PITNGA-2011-289442), CiCYT through the project FPA2009-09017, CAM through the project HEPHACOS P-ESP-00346, MICINN through the grant BES-2010-037869 and the Juan de la Cierva programme (JCI-2011-09244), Italian Ministero dell'Universitá e della Ricerca Scientifica through the COFIN program (PRIN 2008) and the contracts MRTN-CT-2006- 035505 and PITN-GA-2009-237920 (UNILHC). The authors also acknowledge the support of the Spanish MINECO's "Centro de Excelencia Severo Ochoa" Programme under grant SEV-2012-0249