Dark matter induced nucleon decay through the neutron portal

The neutron portal operator provides a theoretically motivated connection between the visible and dark sectors and features in several well-studied asymmetric dark matter models. This operator leads to dark matter induced nucleon decays that mimic the experimental signature of “ordinary” nucleon decays. In this work, we reinterpret Super-Kamiokande nucleon decay searches for <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mi>n</a:mi> <a:mo stretchy="false">→</a:mo> <a:msup> <a:mi>π</a:mi> <a:mn>0</a:mn> </a:msup> <a:mi>ν</a:mi> </a:math> and <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"> <d:mi>p</d:mi> <d:mo stretchy="false">→</d:mo> <d:msup> <d:mi>π</d:mi> <d:mo>+</d:mo> </d:msup> <d:mi>ν</d:mi> </d:math> to constrain dark matter induced nucleon decays. For GeV-scale dark matter, we obtain lower bounds of <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"> <g:mi mathvariant="script">O</g:mi> <g:mo stretchy="false">(</g:mo> <g:mn>1</g:mn> <g:mtext> </g:mtext> <g:mtext> </g:mtext> <g:mi>TeV</g:mi> <g:mo stretchy="false">)</g:mo> </g:math> on the scale of the effective neutron portal operator. We also discuss the prospects for future searches at Hyper-Kamiokande and highlight the importance of a dedicated experimental analysis with reduced systematic uncertainties.