arXiv subjects

P. Fernández

Publications and source records attributed to P. Fernández.

3 recordsLinked to original sources

arXiv2024

Measuring Oscillations with A Million Atmospheric Neutrinos

After two decades of measurements, neutrino physics is now advancing into the precision era. Withthe long-baseline experiments designed to tackle current open questions, a new query arises: can atmospheric neutrino experiments also play a role? To that end, we analyze the expected sensitivity of current and near-future water(ice)-Cherenkov atmospheric neutrino experiments in the context of standard three-flavor neutrino oscillations. In this first in depth combined atmospheric neutrino analysis, we analyze the current shared systematic uncertainties arising from the common flux and neutrino-water interactions. We then implement the systematic uncertainties of each experiment in detail and develop the atmospheric neutrino simulations for Super-Kamiokande, with and without neutron-tagging capabilities, IceCube Upgrade, ORCA, and Hyper-Kamiokande detectors. We carefully review the synergies and features of these experiments to examine the potential of a joint analysis of these atmospheric neutrino data in resolving the $θ_{23}$ octant at 99% confidence level, and determining the neutrino mass ordering above 5$σ$ by 2030. Additionally, we assess the capability to constrain $θ_{13}$ and the CP -violating phase ($δ_{CP}$) in the leptonic sector independently from reactor and accelerator neutrino data. A combination of the atmospheric neutrino measurements will enhance the sensitivity to a greater extent than the simple sum of individual experiment results reaching more than 3$σ$ for some values of $δ_{CP}$ . These results will provide vital information for next-generation accelerator neutrino oscillation experiments such as DUNE and Hyper-Kamiokande.

hep-ph↗

arXiv2023

Growth of Zr/ZrO2 core-shell structures by Fast Thermal Oxidation

This research has been conducted to characterize and validate the resistive heating as a synthesis method for zirconium oxides (ZrO$_2$). A wire of Zr has been oxidized to form a core shell structure, in which the core is the metal wire, and the shell is an oxide layer around 10$μ$m thick. The characterization This research has been conducted to characterize and validate the resistive heating as a synthesis method for zirconium oxides (ZrO$_2$). A wire of Zr has been oxidized to form a core shell structure, in which the core is the metal wire, and the shell is an oxide layer around 10$μ$m thick. The characterization of the samples has been performed by means of Scanning Electron Microscopy (SEM). The chemical composition was analysed by X-ray spectroscopy (EDX). X-ray diffraction (XRD) and Raman spectroscopy have been used to assess crystallinity and crystal structure. Photoluminescence (PL) and cathodoluminescence (CL) measurements have allowed us to study the distribution of defects along the shell, and to confirm the degree of uniformity. The oxygen vacancies, either as isolated defects or forming complexes with impurities, play a determinant role in the luminescent processes. Colour centres, mainly electron centres as F, F$_A$ and F$_{AA}$, give rise to several visible emissions extending from blue to green, with main components around 2eV, 2.4-2.5eV and 2.7eV. The differences between PL and CL are also discussed.

cond-mat.mtrl-sci↗

arXiv2015

Physics Potential of a Long Baseline Neutrino Oscillation Experiment Using J-PARC Neutrino Beam and Hyper-Kamiokande

Hyper-Kamiokande will be a next generation underground water Cherenkov detector with a total (fiducial) mass of 0.99 (0.56) million metric tons, approximately 20 (25) times larger than that of Super-Kamiokande. One of the main goals of Hyper-Kamiokande is the study of $CP$ asymmetry in the lepton sector using accelerator neutrino and anti-neutrino beams. In this paper, the physics potential of a long baseline neutrino experiment using the Hyper-Kamiokande detector and a neutrino beam from the J-PARC proton synchrotron is presented. The analysis uses the framework and systematic uncertainties derived from the ongoing T2K experiment. With a total exposure of 7.5 MW $\times$ 10$^7$ sec integrated proton beam power (corresponding to $1.56\times10^{22}$ protons on target with a 30 GeV proton beam) to a $2.5$-degree off-axis neutrino beam, it is expected that the leptonic $CP$ phase $δ_{CP}$ can be determined to better than 19 degrees for all possible values of $δ_{CP}$, and $CP$ violation can be established with a statistical significance of more than $3\,σ$ ($5\,σ$) for $76\%$ ($58\%$) of the $δ_{CP}$ parameter space. Using both $ν_e$ appearance and $ν_μ$ disappearance data, the expected 1$σ$ uncertainty of $\sin^2θ_{23}$ is 0.015(0.006) for $\sin^2θ_{23}=0.5(0.45)$.

hep-ex↗