Proton Decay in Supersymmetric $SU(4{)}_c\times SU(2{)}_L\times SU(2{)}_R$

Abstract

We discuss proton decay in a recently proposed model of supersymmetric hybrid inflation based on the gauge symmetry $SU(4{)}_c\times SU(2{)}_L\times SU(2{)}_R$. A $U(1)R$ symmetry plays an essential role in realizing inflation as well as in eliminating some undesirable baryon number violating operators. Proton decay is primarily mediated by a variety of color triplets from chiral superfields, and it lies in the observable range for a range of intermediate scale masses for the triplets. The decay modes include $p\to e^{+}({\mu }^{+})+{\pi }^0$, $p\to \bar{\nu }+{\pi }^{+}$, $p\to K^0+e^{+}({\mu }^{+})$, and $p\to K^{+}+\bar{\nu }$, with a lifetime estimate of order $10^{34}-10^{36}$ yrs and accessible at Hyper-Kamiokande and future upgrades. The unification at the Grand Unified Theory (GUT) scale $M_{\mathrm{GUT}}$ ($\sim 10^{16}$ GeV) of the Minimal Supersymmetric Standard Model (MSSM) gauge couplings is briefly discussed.

Comments: Version-2: 20 pages, 7 figures, version published in JHEP