Proton decay: flipped vs. unflipped SU(5)
John Ellis, Marcos A. G. Garcia, Natsumi Nagata, Dimitri V. Nanopoulos, Keith A. Olive
Abstract
A bstract We analyze nucleon decay modes in a no-scale supersymmetric flipped SU(5) GUT model, and contrast them with the predictions for proton decays via dimension-6 operators in a standard unflipped supersymmetric SU(5) GUT model. We find that these GUT models make very different predictions for the ratios Γ( p → π 0 μ + ) / Γ( p → π 0 e + ), Γ( p → $$ {\pi}^{+}\overline{\nu} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>π</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:mover> <mml:mi>ν</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> ) / Γ( p → π 0 e + ), Γ( p → K 0 e + ) / Γ( p → π 0 e + ) and Γ( p → K 0 μ + ) / Γ( p → π 0 μ + ), and that predictions for the ratios Γ( p → π 0 μ + ) / Γ( p → π 0 e + ) and Γ( p → $$ {\pi}^{+}\overline{\nu} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>π</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:mover> <mml:mi>ν</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> ) / Γ( p → π 0 e + ) also differ in variants of the flipped SU(5) model with normal- or inverse-ordered light neutrino masses. Upcoming large neutrino experiments may have interesting opportunities to explore both GUT and flavour physics in proton and neutron decays.