Neutrino Parameters from Reactor and Accelerator Neutrino Experiments

We revisit correlations of neutrino oscillation parameters in reactor and long-baseline neutrino oscillation experiments. A framework based on an effective value of $\theta_{13}$ is presented, which can easily reproduce experimental results. It also clarifies why current and future long-baseline experiments will have less precision on values around $\delta_{CP} = \pm \pi/2$ than on values around $\delta_{CP} = 0$. Optimization potential for the determination of the theoretically very interesting values around $\delta_{CP} = -\pi/2$ is also pointed out, which would require that future runs of accelerator experiments are not equally shared $1:1$ in neutrino and antineutrino modes, but rather $2:1$. Recent hints on the CP phase and the mass ordering are then considered from the point of view that different reactor and long-baseline neutrino experiments provide currently different best-fit values of $\theta_{13}$ and $\theta_{23}$. We point out that the significance of the hints changes for the different available best-fit values.Comment: 16pages, 9 figures, matches the version to be published in PR

Hadron Production Measurements for Long-Baseline Neutrino Experiments with NA61/SHINE

A precise prediction of the neutrino flux is a key ingredient for achieving the physics goals of long-baseline neutrino experiments. In modern accelerator-based neutrino experiments, neutrino beams are created from the decays of secondary hadrons produced in hadron-nucleus interactions. Hadron production is the leading systematic uncertainty source on the neutrino flux prediction; therefore, its precise measurement is essential. The NA61/SHINE is a fixed-target experiment at the CERN Super Proton Synchrotron, which studies hadron production in hadron-nucleus and nucleus-nucleus collisions for various physics goals. For neutrino physics, light hadron beams (protons, pions, and kaons) are collided with a light nuclear target (carbon, aluminum, and beryllium) and spectra of outgoing hadrons are measured. These proceedings will review the recent results and ongoing hadron production measurements with NA61/SHINE for the precise neutrino flux predictions in the T2K and Fermilab long-baseline neutrino experiments. It will also discuss the prospects for future hadron production measurements with NA61/SHINE beyond 2020, after the Long Shutdown 2 of the accelerator complex at CERN.Comment: Talk presented at CIPANP2018. 8 pages, LaTeX, 8 figures. arXiv admin note: text overlap with arXiv:1705.0053

Where we are on θ13\theta_{13}: addendum to "Global neutrino data and recent reactor fluxes: status of three-flavour oscillation parameters"

In this addendum to arXiv:1103.0734 we consider the recent results from long-baseline $\nu_\mu\to\nu_e$ searches at the T2K and MINOS experiments and investigate their implications for the mixing angle $\theta_{13}$ and the leptonic Dirac CP phase $\delta$. By combining the $2.5\sigma$ indication for a non-zero value of $\theta_{13}$ coming from T2K data with global neutrino oscillation data we obtain a significance for $\theta_{13} > 0$ of about $3\sigma$ with best fit points $\sin^2\theta_{13} = 0.013(0.016)$ for normal (inverted) neutrino mass ordering. These results depend somewhat on assumptions concerning the analysis of reactor neutrino data.Comment: 5 pages, 2 figures and 1 tabl

Status of three-neutrino oscillation parameters

Here we review the current status of global fits to neutrino oscillation data within the three-flavour framework. In our analysis we include the most recent data from solar and atmospheric neutrino experiments as well as the latest results from the long-baseline accelerator neutrino experiments and the recent measurements of reactor neutrino disappearance reported by Double Chooz, Daya Bay and RENO. We present updated determinations for the two neutrino mass splittings and the three mixing angles responsible for neutrino oscillations that, for the first time, have all been measured with 1 sigma accuracies ranging from 3 to 15%. A weak sensitivity for the CP violating phase is also reported from the global analysis

Global neutrino data and recent reactor fluxes: status of three-flavour oscillation parameters

We present the results of a global neutrino oscillation data analysis within the three-flavour framework. We include latest results from the MINOS long-baseline experiment (including electron neutrino appearance as well as anti-neutrino data), updating all relevant solar (SK II+III), atmospheric (SK I+II+III) and reactor (KamLAND) data. Furthermore, we include a recent re-calculation of the anti-neutrino fluxes emitted from nuclear reactors. These results have important consequences for the analysis of reactor experiments and in particular for the status of the mixing angle $\theta_{13}$. In our recommended default analysis we find from the global fit that the hint for non-zero $\theta_{13}$ remains weak, at 1.8$\sigma$ for both neutrino mass hierarchy schemes. However, we discuss in detail the dependence of these results on assumptions concerning the reactor neutrino analysis.Comment: 15 pages, 10 figures and 2 tables, v2: corrected version, main conclusions unchanged, references adde

Probing Dual NSI and CP Violation in DUNE and T2HK

The latest results from the long baseline neutrino experiments show a hint of non-zero CP violation in the neutrino sector. In this article, we study the CP violation effects in the upcoming long-baseline neutrino experiments DUNE and T2HK. Non-standard interactions can affect the cleaner determination of CP violation parameter. It has been argued that the NSI can help alleviate the tension between the recent $\delta_{CP}$ measurements of NO$\nu$A and T2K experiments. We consider here the dual NSI due to $\epsilon_{e\mu}$ and $\epsilon_{e\tau}$, arising simultaneously to see the effects in neutrino oscillation probabilities. Moreover, the CP asymmetry parameter $A_{CP}$ exhibits a clear distinction between normal and inverted mass orderings in the DUNE experiment.Comment: 30 pages, 46 figures. arXiv admin note: text overlap with arXiv:2302.0959