Testable flavored TeV-scale resonant leptogenesis with MeV-GeV dark matter in a neutrinophilic two-Higgs-doublet model

We explore flavored resonant leptogenesis embedded in a neutrinophilic two-Higgs-doublet model. Successful leptogenesis is achieved by the very mildly degenerate two heavier right-handed neutrinos (RHNs) <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msub><a:mi>N</a:mi><a:mn>2</a:mn></a:msub></a:math> and <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msub><c:mi>N</c:mi><c:mn>3</c:mn></c:msub></c:math> with a level of only <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mrow><e:mi mathvariant="normal">Δ</e:mi><e:msub><e:mrow><e:mi>M</e:mi></e:mrow><e:mrow><e:mn>32</e:mn></e:mrow></e:msub><e:mo>/</e:mo><e:msub><e:mrow><e:mi>M</e:mi></e:mrow><e:mrow><e:mn>2</e:mn></e:mrow></e:msub><e:mo>∼</e:mo><e:mi mathvariant="script">O</e:mi><e:mo stretchy="false">(</e:mo><e:mn>0.1</e:mn><e:mo>%</e:mo><e:mi>–</e:mi><e:mn>1</e:mn><e:mo>%</e:mo><e:mo stretchy="false">)</e:mo></e:mrow></e:math>. The lightest RHN, with a MeV–GeV mass, lies below the sphaleron freeze-out temperature and is stable, serving as a dark matter candidate. The model enables TeV-scale leptogenesis while avoiding the extreme mass degeneracy typically plaguing conventional resonant leptogenesis. Baryon asymmetry, neutrino masses, and potentially even dark matter relic density can be addressed within a unified, experimentally testable framework.