Neutrino Lorentz invariance violation and ultralight axionlike dark matter searches at the European Spallation Source

The dark matter conundrum stands out as one of the central challenges to understand in both particle physics and cosmology. The ultralight axionlike particle (UALP) is an appealing dark matter candidate that can be searched for in neutrino oscillation experiments. In this work, we examine the interaction among neutrinos and a UALP—such interaction might induce violations of the Lorentz and <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>C</a:mi><a:mi>P</a:mi><a:mi>T</a:mi></a:math> symmetries. We assess the sensitivity to both the isotropic <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mi>C</c:mi><c:mi>P</c:mi><c:mi>T</c:mi></c:math>-odd standard model extension coefficients <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mo stretchy="false">(</e:mo><e:msub><e:mi>a</e:mi><e:mi>L</e:mi></e:msub><e:msup><e:mo stretchy="false">)</e:mo><e:mi>T</e:mi></e:msup></e:math> and effective neutrino-UALP couplings <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:mover accent="true"><i:mi>g</i:mi><i:mo stretchy="false">˜</i:mo></i:mover></i:math> at the next-to-next-generation neutrino oscillation experiment at the European Spallation Source. Published by the American Physical Society 2024