A Search for Neutral Current Single Gamma with ND280 at T2K

The methodology and preliminary results for the search of single photons initiated by Neutral Current neutrino interactions with the ND280 detector at the T2K experiment are presented. This measurement aims to set the first limit on single-photon neutrino production below 1~GeV. Neutrino production of single photon is a subdominant process in neutrino interactions. Because photons and electrons have very similar signatures in neutrino detectors, careful estimations need to be made not to bias the \nue appearance oscillation results of accelerator neutrino experiments. The single photons are created by a nuclear resonance (typically $\Delta$(1232)) after interaction of the neutrino. The cross section is expected to be of the order of $10^{-42} cm^{2}$. The main background is composed of $\pi^{0}$ decaying into two photons, where only one photon is detected, and $\pi^{0}$ events creating photons from outside of the fiducial volume.Comment: Submitted for NuInt2015 proceeding

A search for neutrino-induced single photons and measurement of oscillation analysis systematic errors with electron and anti-electron neutrino selections, using the o -axis near detector of the Tokai to Kamioka experiment

PhDThis thesis describes the search for neutrino-production of single photons using the o - axis near detector at 280 metres (ND280) of the T2K experiment. A photon selection is used to perform the searches using the rst Fine Grained Detector (FGD1) of the ND280. The thesis also highlights the importance of systematic uncertainties in the analysis, since the selection is background dominated. After careful characterisation of the systematic uncertainties and estimation of the e ciency, it is concluded that, with the selected 39 data events and the expected background of 45 events, the limit for neutrino-induced single photons, at T2K energies, is 0:0903 x 10-38cm2=nucleon. This result can be com- pared with the expected limit of 0:1068 x 10-38cm2=nucleon. Using ND280's neutrino energy distribution (peaked at 600 MeV), NEUT predicts a ux-averaged cross section of 0:000239 x 10-38cm2=nucleon. A t to the muon and electron (anti-) neutrinos selections in the ND280 was per- formed. The aim of this analysis is to use a data-driven method to constrain the electron (anti-) neutrinos background events at SK, the far detector and electron neutrino cross section parameters for oscillation analyses. These are fundamental inputs in the context of the searches for Charge-Parity (CP) violation in the neutrino sector. After a t to the nominal Monte Carlo was realised, the electron neutrino and anti-neutrino cross sec- tion normalisation uncertainties are found to be 7:6% and 19:3%, repectively. Although these numbers are much higher than the assumed 3% uncertainty of all the CP violation searches performed at T2K up to now, the difference in the CP log-likelihood is found to be acceptable as the one sigma contours are not very di erent and the exclusion of the CP = 0 is roughly the same

Synergies and Prospects for Early Resolution of the Neutrino Mass Ordering

The measurement of neutrino Mass Ordering (MO) is a fundamental element for the understanding of leptonic flavour sector of the Standard Model of Particle Physics. Its determination relies on the precise measurement of $\Delta m^2_{31}$ and $\Delta m^2_{32}$ using either neutrino vacuum oscillations, such as the ones studied by medium baseline reactor experiments, or matter effect modified oscillations such as those manifesting in long-baseline neutrino beams (LB$\nu$B) or atmospheric neutrino experiments. Despite existing MO indication today, a fully resolved MO measurement ($\geq$5$\sigma$) is most likely to await for the next generation of neutrino experiments: JUNO, whose stand-alone sensitivity is $\sim$3$\sigma$, or LB$\nu$B experiments (DUNE and Hyper-Kamiokande). Upcoming atmospheric neutrino experiments are also expected to provide precious information. In this work, we study the possible context for the earliest full MO resolution. A firm resolution is possible even before 2028, exploiting mainly vacuum oscillation, upon the combination of JUNO and the current generation of LB$\nu$B experiments (NOvA and T2K). This opportunity is possible thanks to a powerful synergy boosting the overall sensitivity where the sub-percent precision of $\Delta m^2_{32}$ by LB$\nu$B experiments is found to be the leading order term for the MO earliest discovery. We also found that the comparison between matter and vacuum driven oscillation results enables unique discovery potential for physics beyond the Standard Model.Comment: Entitled in arXiv:2008.11280v1 as "Earliest Resolution to the Neutrino Mass Ordering?

LiquidO: An Appetiser for Beam Physics Capabilities

<p>The first release of the LiquidO detector's possible capabilities in the context of accelerator-based neutrino detection in the GeV regime as well as proton decay. Discussion done in the context of the "DUNE Module of Opportunity Workshop" discussion.</p>The first release of the LiquidO detector's possible capabilities in the context of accelerator-based neutrino detection in the GeV regime as well as proton decay

Synergies and prospects for early resolution of the neutrino mass ordering

The measurement of neutrino mass ordering (MO) is a fundamental element for the understanding of leptonic flavour sector of the Standard Model of Particle Physics. Its determination relies on the precise measurement of Δm312 and Δm322 using either neutrino vacuum oscillations, such as the ones studied by medium baseline reactor experiments, or matter effect modified oscillations such as those manifesting in long-baseline neutrino beams (LBνB) or atmospheric neutrino experiments. Despite existing MO indication today, a fully resolved MO measurement (≥ 5 σ) is most likely to await for the next generation of neutrino experiments: JUNO, whose stand-alone sensitivity is ∼ 3 σ, or LBνB experiments (DUNE and Hyper-Kamiokande). Upcoming atmospheric neutrino experiments are also expected to provide precious information. In this work, we study the possible context for the earliest full MO resolution. A firm resolution is possible even before 2028, exploiting mainly vacuum oscillation, upon the combination of JUNO and the current generation of LBνB experiments (NOvA and T2K). This opportunity is possible thanks to a powerful synergy boosting the overall sensitivity where the sub-percent precision of Δm322 by LBνB experiments is found to be the leading order term for the MO earliest discovery. We also found that the comparison between matter and vacuum driven oscillation results enables unique discovery potential for physics beyond the Standard Model

Earliest Resolution to the Neutrino Mass Ordering?

We hereby illustrate and numerically demonstrate via a simplified proof of concept calculation tuned to the latest average neutrino global data that the combined sensitivity of JUNO with NOvA and T2K experiments has the potential to be the first fully resolved ($\geq$5$\sigma$) measurement of neutrino Mass Ordering (MO) around 2028; tightly linked to the JUNO schedule. Our predictions account for the key ambiguities and the most relevant $\pm$1$\sigma$ data fluctuations. In the absence of any concrete MO theoretical prediction and given its intrinsic binary outcome, we highlight the benefits of having such a resolved measurement in the light of the remarkable MO resolution ability of the next generation of long baseline neutrino beams experiments. We motivate the opportunity of exploiting the MO experimental framework to scrutinise the standard oscillation model, thus, opening for unique discovery potential, should unexpected discrepancies manifest. Phenomenologically, the deepest insight relies on the articulation of MO resolved measurements via at least the two possible methodologies matter effects and purely vacuum oscillations. Thus, we argue that the JUNO vacuum MO measurement may feasibly yield full resolution in combination to the next generation of long baseline neutrino beams experiments

Earliest Resolution to the Neutrino Mass Ordering?

We hereby illustrate and numerically demonstrate via a simplified proof of concept calculation tuned to the latest average neutrino global data that the combined sensitivity of JUNO with NOvA and T2K experiments has the potential to be the first fully resolved ($\geq$5$\sigma$) measurement of neutrino Mass Ordering (MO) around 2028; tightly linked to the JUNO schedule. Our predictions account for the key ambiguities and the most relevant $\pm$1$\sigma$ data fluctuations. In the absence of any concrete MO theoretical prediction and given its intrinsic binary outcome, we highlight the benefits of having such a resolved measurement in the light of the remarkable MO resolution ability of the next generation of long baseline neutrino beams experiments. We motivate the opportunity of exploiting the MO experimental framework to scrutinise the standard oscillation model, thus, opening for unique discovery potential, should unexpected discrepancies manifest. Phenomenologically, the deepest insight relies on the articulation of MO resolved measurements via at least the two possible methodologies matter effects and purely vacuum oscillations. Thus, we argue that the JUNO vacuum MO measurement may feasibly yield full resolution in combination to the next generation of long baseline neutrino beams experiments

Earliest Resolution to the Neutrino Mass Ordering?

We hereby illustrate and numerically demonstrate via a simplified proof of concept calculation tuned to the latest average neutrino global data that the combined sensitivity of JUNO with NOvA and T2K experiments has the potential to be the first fully resolved ($\geq$5$\sigma$) measurement of neutrino Mass Ordering (MO) around 2028; tightly linked to the JUNO schedule. Our predictions account for the key ambiguities and the most relevant $\pm$1$\sigma$ data fluctuations. In the absence of any concrete MO theoretical prediction and given its intrinsic binary outcome, we highlight the benefits of having such a resolved measurement in the light of the remarkable MO resolution ability of the next generation of long baseline neutrino beams experiments. We motivate the opportunity of exploiting the MO experimental framework to scrutinise the standard oscillation model, thus, opening for unique discovery potential, should unexpected discrepancies manifest. Phenomenologically, the deepest insight relies on the articulation of MO resolved measurements via at least the two possible methodologies matter effects and purely vacuum oscillations. Thus, we argue that the JUNO vacuum MO measurement may feasibly yield full resolution in combination to the next generation of long baseline neutrino beams experiments

Earliest Resolution to the Neutrino Mass Ordering?

We hereby illustrate and numerically demonstrate via a simplified proof of concept calculation tuned to the latest average neutrino global data that the combined sensitivity of JUNO with NOvA and T2K experiments has the potential to be the first fully resolved ($\geq$5$\sigma$) measurement of neutrino Mass Ordering (MO) around 2028; tightly linked to the JUNO schedule. Our predictions account for the key ambiguities and the most relevant $\pm$1$\sigma$ data fluctuations. In the absence of any concrete MO theoretical prediction and given its intrinsic binary outcome, we highlight the benefits of having such a resolved measurement in the light of the remarkable MO resolution ability of the next generation of long baseline neutrino beams experiments. We motivate the opportunity of exploiting the MO experimental framework to scrutinise the standard oscillation model, thus, opening for unique discovery potential, should unexpected discrepancies manifest. Phenomenologically, the deepest insight relies on the articulation of MO resolved measurements via at least the two possible methodologies matter effects and purely vacuum oscillations. Thus, we argue that the JUNO vacuum MO measurement may feasibly yield full resolution in combination to the next generation of long baseline neutrino beams experiments