2024/11/19 by Jesús-Valls, César, Petcov, Serguey T., Xia, Junjie
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2411.12344
Using PREM as a reference model for the Earth density distribution we investigate the sensitivity of the Hyper-Kamiokande (HK) detector to deviations of the Earth i) core average density ρC, ii) lower mantle average density ρlman) and iii) upper mantle average density ρuman, from their respective PREM densities. The analysis is performed by studying the effects of the Earth matter on the oscillations of atmospheric νμ, νe, νμ and νe. We implement the constraints on the variations of ρC, ρlman and ρuman following from the precise knowledge of the Earth mass M_⊕ and moment of inertia I_⊕, as well as from the requirement that the Earth be in hydrostatic equilibrium (EHE). These constraints limit in the case of the three layer Earth density structure we are considering the maximal positive deviation of ρC from its PREM value to 10%. Considering the case of normal ordering (NO) of neutrino masses, we present results which illustrate the dependence of sensitivity to the core, lower and upper mantle average densities on the energy and zenith angle resolutions and on the value of θ23. We show, in particular, that in the ''nominal'' case of neutrino energy resolution Eres = 30% and zenith angle resolution θzres = 20^∘ and for, e.g., sin2θ23=0.45~(0.58), HK can determine the average core density ρC at 2σ C.L. after 6500 days of operation with an uncertainty of (-14.5%)/+39.5% ((-9.3%/+31.7%). In the ''more favorable'' case of Eres= 20% and θzres = 10^∘, and if sin2θ23=0.58~(0.45), the core density would be determined at 2σ C.L. with an uncertainty of (-8.3%)/+9.8% ((-9.2%)/+11.3%).