J. García-Ravelo | Searcharxiv

arXiv2026

Theoretical analysis of the effect of the kinetic energy operator on double heterostructure spectra

We report an analytical and numerical study of the effect of kinetic energy operator (KEO) ambiguity on the energy spectra of double heterostructures when the mass of the charge carriers, subjected to a potential, depends on position. The spectra are calculated using two complementary techniques. In the first case, which is not always possible, the energy spectrum satisfies a transcendental equation, which is obtained through an analytical process. While in the second, which can be used practically in any double heterostructure (DH), the energy spectra correspond to the poles of the reflection coefficient of the heterostructure. The spectra thus obtained complement those already reported in a previous reference, since we now include the spectra of another KEO. Finally, we show how these methods allow us to critically analyze some statements that have been made about the relevance of some kinetic energy operators in some simpler heterostructures.

math-ph↗

arXiv2018

Confidence regions for neutrino oscillation parameters from double-Chooz data

In this work, an independent and detailed statistical analysis of the double-Chooz experiment is performed. To have a thorough understanding of the implications of the double-Chooz data on both oscillation parameters $\sin^{2}(2θ_{13})$ and $Δm^2_{31}$, we decided to analyze the data corresponding to the Far detector, with no additional restriction. By doing this, confidence regions and best fit values are obtained for ($\sin^{2}(2θ_{13}),Δm^2_{31}$). This analysis yields an out-of-order $Δm^2_{31}$ minimum, which has already been mentioned in previous works, and it is corrected with the inclusion of additional restrictions. With such restrictions it is obtained that $\sin ^{2}(2 θ_{13})=0{.}084_{-0{.}028}^{+0{.}030}$ and $Δm^2_{31}=2.444^{+0.187}_{-0.215} \times 10^{-3}$ eV$^2$/c$^4$. Our analysis allows us to study the effects of the so called "spectral bump" around 5 MeV, it is observed that a variation of this spectral bump may be able to move the $Δm^2_{31}$ best fit value, in such a way that $Δm^2_{31}$ takes the order of magnitude of the MINOS value. Finally, and with the intention of understanding the effects of the preliminary Near detector data, we performed two different analyses, aiming to eliminate the effects of the energy bump. As a consequence, it is found that unlike the Far Detector analysis, the Near detector data may be able to fully determine both oscillation parameters by itself, resulting in, $\sin^2(2θ_{13}) = 0.095 \pm 0.053$ and $Δm^{2}_{31} = 2.63^{+0.98}_{-1.15} \times 10^{-3} \text{eV}^2 / \text{c}^4$. The later analyses represent an improvement with respect to previous works, where additional constraints for $Δm^2_{31}$ were necessary.

hep-ph↗