1993/04/06 by Peter Cho · 4 citations
Physics and Astronomy · #Neutrino Physics Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1103/physrevd.48.5331
published as Phys.Rev.D48:5331-5341,1993 · 22 pages with 2 figures not included but available upon request, CALT-68-1859
arxiv created 1993/04/06 · openalex publication_date 1993/12/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A set of grand unified theories based upon the gauge groups SU(5)L\ifmmode×\else\texttimes\fiSU(5)R, SO(10)L\ifmmode×\else\texttimes\fiSO(10)R and SU(4)C\ifmmode×\else\texttimes\fiSU(4)L\ifmmode×\else\texttimes\fiSU(4)R is explored. Several novel features distinguish these theories from the well-known SU(5), SO(10), and SU(4)C\ifmmode×\else\texttimes\fiSU(2)L\ifmmode×\else\texttimes\fiSU(2)R models which they generalize. Firstly, standard model quarks and leptons are accompanied by and mix with heavy SU(2)L\ifmmode×\else\texttimes\fiSU(2)R singlet partners. The resulting fermion mass matrices are seesaw in form. Discrete parity symmetries render the determinants of these mass matrices real and eliminate CP-violating gauge terms. The unified seesaw models consequently provide a possible resolution to the strong CP problem. Secondly, sin2\mathrm\ensuremathθW at the unification scale is numerically smaller than the experimentally measured Z scale value. The weak angle must therefore increase as it evolves down in energy. Finally, proton decay is suppressed by small seesaw mixing factors in all these theories.