Nucleon decay and n- n ¯ oscillations in a left-right symmetric model with large extra dimensions NUCLEON DECAY and N- N ¯ OSCILLATIONS in ⋯ GIRMOHANTA SUDHAKANTHA and SHROCK ROBERT

We study baryon-number-violating processes, including proton and bound neutron decays and n-n¯ oscillations, in a left-right-symmetric (LRS) model in which quarks and leptons have localized wave functions in extra dimensions. In this model we show that, while one can easily suppress baryon-number-violating nucleon decays well below experimental bounds, this does not suppress n-n¯ transitions, which may occur at levels comparable to current limits. This is qualitatively similar to what was found in an extra-dimensional model with a Standard-Model low-energy effective field theory (SMEFT). We show that experimental data imply a lower limit on the mass scale Mnn¯ characterizing the physics responsible for n-n¯ oscillations in the LRS model that is significantly higher than in the extra-dimensional model using a SMEFT and explain the reason for this. Our results provide further motivation for new experiments to search for n-n¯ oscillations.