Study of quantum decoherence at the Protvino to ORCA experiment

Protvino to ORCA (oscillation research with cosmics in the abyss) (P2O) is an upcoming neutrino oscillation experiment with a very long baseline of 2595 km. Because of the substantial baseline, this experiment provides a unique opportunity to study the Earth matter effects over very large distances. This makes it a suitable experiment to investigate the environmental decoherence in neutrino oscillations, where the neutrino system could interact with a stochastic environment and lead to a loss in the coherence of neutrino states. In this work, we consider an open quantum system framework to simulate the neutrino oscillations in the P2O experiment and obtain bounds on the decoherence parameters in different phenomenological models. Here, we also consider that the decoherence parameter <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi mathvariant="normal">Γ</a:mi></a:math> depends on neutrino energy <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"><d:msub><d:mi>E</d:mi><d:mi>ν</d:mi></d:msub></d:math> as <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" display="inline"><f:msub><f:mi mathvariant="normal">Γ</f:mi><f:mrow><f:mi>j</f:mi><f:mi>k</f:mi></f:mrow></f:msub><f:mo stretchy="false">(</f:mo><f:msub><f:mi>E</f:mi><f:mi>ν</f:mi></f:msub><f:mo stretchy="false">)</f:mo><f:mo>=</f:mo><f:msub><f:mi mathvariant="normal">Γ</f:mi><f:mn>0</f:mn></f:msub><f:mo stretchy="false">(</f:mo><f:mfrac><f:msub><f:mi>E</f:mi><f:mi>ν</f:mi></f:msub><f:msub><f:mi>E</f:mi><f:mn>0</f:mn></f:msub></f:mfrac><f:msup><f:mo stretchy="false">)</f:mo><f:mi>n</f:mi></f:msup></f:math>. Furthermore, assuming the presence of decoherence in nature, we study the effect of it on the determination of neutrino mass hierarchy and <n:math xmlns:n="http://www.w3.org/1998/Math/MathML" display="inline"><n:mrow><n:mi>C</n:mi><n:mi>P</n:mi></n:mrow></n:math> violation at the P2O experiment.