Resolving the octant of theta(23) via radiative mu-tau symmetry breaking

We point out that the observed neutrino mixing pattern at low energies is very likely to originate from the 3 x 3 Pontecorvo-Maki-Nakagawa-Sakata (PMNS) lepton flavor mixing matrix U which possesses the exact mu-tau permutation symmetry vertical bar U-mu i vertical bar = vertical bar U-tau i vertical bar (for i = 1, 2, 3) at a superhigh energy scale Lambda(mu tau) similar to 10(14) GeV. The deviation of theta(23) from 45 degrees and that of delta from 270 degrees in the standard parametrization of U are therefore a natural consequence of small PMNS mu-t symmetry breaking via the renormalization-group equations (RGEs) running from Lambda(mu tau) down to the electroweak scale Lambda(EW) similar to 10(2) GeV. We find that the RGE-corrected value of theta(23) is uniquely correlated with the neutrino mass ordering. In the minimal supersymmetric standard model, the best-fit results theta(23) similar or equal to 42.4 degrees reported by Capozzi et al. (or theta(23) similar or equal to 48.9 degrees reported by Forero et al.) at Lambda(EW) can arise from theta(23) = 45 degrees at Lambda(mu tau) if the neutrino mass ordering is inverted (or normal). Accordingly, the preliminary best-fit results of d at Lambda(EW) can also evolve from delta = 270 degrees at Lambda(mu tau) no matter whether the massive neutrinos are Dirac or Majorana particles.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000344111100001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)4ARTICLEluoshu@xmu.edu.cn; xingzz@ihep.ac.cn7null9