已充分确立的中微子振荡现象证实了中微子具有质量，且带电轻子与中性轻子存在混合，该现象已被广泛用于探究这种难以捉摸的粒子的物理性质。然而，由两个质量平方差、三个混合角和一个狄拉克 CP 破坏相位所决定的中微子振荡的完整描述尚未达成。正在进行的基于加速器的长基线中微子实验 T2K 和 NOvA 对于完善这一图景至关重要。利用截至 2023 年夏季可获得的数据和分析，T2K 在超过 90% 置信水平上倾向于轻子 CP 破坏，而 NOvA 则未显示出对这一迹象的偏好。两个实验均微弱地倾向于正常中微子质量顺序和 $θ_{23}$ 混合角的较高八分圆。
英文摘要：
The well-established neutrino oscillation phenomenon, which confirms neutrinos have mass and the charged and neutral leptons are mixed, has been widely exploited to investigate the physics of this elusive particle. The complete description of neutrino oscillations, which are dictated by two mass-squared splittings, three mixing angles, and one Dirac CP-violation phase, however, has yet to be reached. The ongoing accelerator-based long-baseline neutrino experiments, T2K and NOvA, are critical in completing this picture. Using data and analyses accessible by summer 2023, T2K favors a leptonic CP violation at more than 90\% C.L. while NOvA shows no preference of this indication. Both experiments weakly opt for the \emph{normal} neutrino mass ordering and higher octant of the $θ_{23}$ mixing angle.
NOvA is a long-baseline neutrino oscillation experiment using Fermilab's 700 kW NuMI muon neutrino beam. Two functionally identical scintillator detectors are placed off the beam axis, separated by 810 km oscillation baseline. Both detectors have high active material fractions and are finely segmented allowing for precise identification and analysis of neutrino interactions. By observing both the disappearance of muon (anti)neutrinos and appearance of electron (anti)neutrinos in the beam, NOvA can impose constraints on the yet undetermined parameters of neutrino oscillation phenomenon, such as…
NOvA is a long-baseline accelerator-based neutrino oscillation experiment that is optimized for $ν_μ\toν_e$ measurements. It uses the upgraded NuMI beam from Fermilab and measures electron-neutrino appearance and muon-neutrino disappearance at its Far Detector in Ash River, Minnesota. The $ν_e$ appearance analysis at NOvA aims to resolve the neutrino mass hierarchy problem and to constrain the CP-violating phase. The first data set of $2.74\times10^{20}$ protons on target (POT) equivalent exposure taken by NOvA has been analyzed. The first measurement of electron-neutrino appearance in NOvA pr…
NOvA is a long-baseline neutrino oscillation experiment. It uses the NuMI beam from Fermilab and two sampling calorimeter detectors placed off-axis from the beam. The 293 ton Near Detector measures the unoscillated neutrino energy spectrum, which can be used to predict the neutrino energy spectrum observed at the 14 kton Far Detector. The Near Detector also provides an excellent opportunity to measure neutrino interaction cross sections with high statistics, which will benefit current and future long-baseline neutrino oscillation experiments. This analysis implements new algorithms to identify…
The majority of neutrino oscillation experiments have obtained evidence for neutrino oscillations that are compatible with the three-flavor model. Explaining anomalous results from short-baseline experiments, such as LSND and MiniBooNE, in terms of neutrino oscillations requires the existence of sterile neutrinos. The search for sterile neutrino mixing conducted in NOvA uses a long baseline of 810 km between Near Detector (ND) at Fermilab and Far Detector (FD) in Minnesota. The signal for sterile neutrino oscillations is a deficit of neutral-current neutrino interactions at the FD with respect…
The NOvA long-baseline neutrino oscillation experiment is currently under construction and will use an upgraded NuMI neutrino source at Fermilab and a 14-kton detector at Ash River, Minnesota to explore the neutrino sector. NOvA uses a highly active, finely segmented detector design that offers superb event identification capability, allowing precision measurements of ν_e/ν_e-bar appearance and ν_μ/ν_μ-bar disappearance, through which NOvA will provide constraints on θ_13, θ_23, |Δm^2_atm|, the neutrino mass hierarchy, and the CP-violating phase δ. In this article, we review NOvA's uniquely br…
The NOvA experiment is a long-baseline neutrino oscillation experiment designed to measure electron neutrino appearance in a muon neutrino beam. It consists of two finely segmented, liquid scintillator detectors at 14 mrad off-axis in the NuMI beam.The NOvA Near Detector, located at Fermilab, provides an excellent opportunity to study neutrino-nucleus interactions which are important for the neutrino oscillation measurements. This talk will present one of the first such measurements from the NOvA Near Detector: neutral current coherent-$π^0$ production. Neutrinos can coherently interact with t…
The NOvA experiment is an off-axis long-baseline neutrino oscillation experiment measuring $ν_μ$ disappearance and $ν_{e}$ appearance in a $ν_μ$ beam originating at Fermilab. Oscillations are observed in the far detector relative to measurements made in the near detector, with a full simulation of the beam line and detectors being used to perform extrapolation between them. The neutrino simulation uses the GENIE event generator, which contains implementations of numerous theoretical neutrino interaction models applied to a variety of nuclear targets. However, recent data, recent reanalysis of …
NOvA is a long-baseline neutrino experiment using an off-axis neutrino beam produced by the NuMI neutrino beam at Fermilab. The NOvA experiment will study neutrino $ν_μ\rightarrowν_{e}$ oscillations. A short term goal for the NOvA experiment is to develop a good understanding of the response of the detector. These studies are being carried out with the full Near Detector installed on the surface (NDOS) at Fermilab. This detector is currently running and will acquire neutrino data for a year. Using beam muon neutrino data, quasi-elastic charged-current interactions will be studied. Status of th…
NOvA is a two detector, long baseline neutrino oscillation experiment designed to study $ν_{e}$ ($\barν_{e}$) appearance and $ν_μ$ ($\barν_μ$) disappearance in a $ν_μ$ ($\barν_μ$) beam produced at Fermilab. The near detector (ND) is located 100 meters underground at a distance of 1 km from the target whereas the far detector (FD) is located on the surface, 810 km away from the beam source in Ash River, MN. The ND is used to measure the beam before oscillations and the FD measures the oscillated spectrum. The ND and the FD are functionally identical detectors and the ND spectra are extrapolated…
NOvA is a long-baseline accelerator-based neutrino oscillation experiment that is optimized for $ν_e$ measurements. It uses the upgraded NuMI beam from Fermilab and measures electron-neutrino appearance and muon-neutrino disappearance at its Far Detector in Ash River, Minnesota. The $ν_e$ appearance analysis at NOvA aims to resolve the neutrino mass hierarchy problem and to constrain the CP-violating phase. The first measurement of electron-neutrino appearance in NOvA based on its first year's data was produced in 2015, providing solid evidence of $ν_e$ oscillation with the NuMI beam line and …
The CAFAna framework, initially developed for oscillation analysis with NOvA, is now a key tool in the NOvA, SBN, and DUNE experiments for day-to-day analysis and the production of final oscillation results.
We present a measurement of the electron neutrino charged-current inclusive cross section per nucleon with a data sample corresponding to 2.6E20 protons-on-target collected by NOvA near detector at Fermilab.
NOvA is a long-baseline accelerator-based neutrino oscillation experiment that is optimized for electron-neutrino appearance measurements. It uses the upgraded NuMI beam from Fermilab and consists of a Far Detector in Ash River, Minnesota and a Near Detector at Fermilab. An accurate prediction of the neutrino flux is key to both oscillation and cross-section measurements. The precisely known neutrino-electron elastic scattering cross section provides an in situ constraint on the absolute flux. This talk discusses the status of the measurement of the rate of neutrino-electron elastic scattering…
The NOvA experiment is a long-baseline neutrino oscillation experiment designed to measure the rates of electron neutrino appearance and muon neutrino disappearance. The NOvA near detector is located at Fermilab, 800 m from the primary target and provides an excellent platform to measure and study neutrino-nucleus interactions. We present the status of the measurement of the double differential cross section with respect to muon kinematics for interactions involving charged pions in the final state, $ν_μ + N \rightarrow μ+ π^{+/-} + X$. We have derived a convolutional neural network-based appr…
This paper discusses recent results and near-term prospects of the long-baseline neutrino experiments MINOS, MINOS+, T2K and NOvA. The non-zero value of the third neutrino mixing angle θ13 allows experimental analysis in a manner which explicitly exhibits appearance and disappearance dependencies on additional parameters associated with mass-hierarchy, CP violation, and any non-maximal θ23. These current and near-future experiments begin the era of precision accelerator long-baseline measurements and lay the framework within which future experimental results will be interpreted.
NOvA is a next generation neutrino oscillation experiment designed to search for muon neutrino to electron neutrino oscillations by comparing electron neutrino event rates in a Near Detector at Fermilab with the rates observed in a large Far Detector at Ash River, Minnesota, 810 km from Fermilab. The detectors are totally active, segmented, liquid scintillator detectors and are located 14 mrad off the NuMI beam axis. The Far Detector has begun construction and will begin taking data in early 2013. The experiment aims to measure the neutrino mixing angle theta_13 and will push the search for el…
NOvA is a long-baseline neutrino experiment that uses an upgraded NuMI neutrino source at Fermilab and a 14-kton detector at Ash River, Minnesota. The detector has a highly active, finely segmented design that offers superb event identification capability. This talk presents the latest $ν_μ$ ($\barν_μ$) disappearance and $ν_e$ ($\barν_e$) appearance combined results using the first NOvA anti-neutrino beam data. In the far detector, 18 $\barν_e$ candidate events are observed, with a significance of $\barν_e$ appearance more than 4 $σ$. The NOvA results favor a normal neutrino mass hierarchy.
Over the last several years, our understanding of neutrino oscillations has developed significantly due to the long-baseline measurements of muon-neutrino disappearance and muon-to-electron-neutrino appearance at the T2K and NOvA experiments. However, when interpreted under the standard-three-massive-neutrinos paradigm, a tension has emerged between the two experiments' data. Here, we examine whether this tension can be alleviated when a fourth, very light neutrino is added to the picture. Specifically, we focus on the scenario in which this new neutrino has a mass similar to, or even lighter …
NOvA is a long-baseline neutrino oscillation experiment that will use the NuMI beam originating at Fermilab. NOvA enables the study of two oscillation channels: $ν_μ$ disappearance and $ν_{e}$ appearance. It consists of two functionally identical detectors, the near detector (ND) at Fermilab and the far detector (FD) near International Falls in Northern Minnesota. The ND will be used to study the neutrino beam spectrum and composition before oscillation, and measure background rate to the $ν_e$ appearance search. In this paper, I describe a data-driven technique to estimate the neutral current…
We have produced large and highly-reflective open-cell PVC extrusions for the NOvA neutrino oscillation experiment. The extrusions were sealed, instrumented, assembled into self-supporting detector blocks, and filled with liquid scintillator. Each Far Detector block stands 15.7 m high, is 15.7 m wide and 2.1 m thick. More than 22,000 extrusions were produced with high dimensional tolerance and robust mechanical strength. This paper provides an overview of the NOvA Far Detector, describes the preparation of the custom PVC powder, and the making of the extrusions. Quality control was a key eleme…
The NOvA experiment observes oscillations in two channels (electron-neutrino appearance and muon-neutrino disappearance) using a predominantly muon-neutrino NuMI beam. The Near Detector records multiple overlapping neutrino interactions in each event and the Far Detector has a large background of cosmic rays due to being located on the surface. The oscillation analyses rely on the accurate reconstruction of neutrino interactions in order to precisely measure the neutrino energy and identify the neutrino flavor and interaction mode. Similarly, measurements of neutrino cross sections using the N…
The NuMI Off-Axis v Appearance (NOvA) experiment is a long baseline neutrino oscillation experiment using a neutrino source created from the NuMI Beamline at Fermilab. The experiment will study the oscillations of muon neutrinos to electron neutrinos using two functionally identical plastic, liquid scintillator filled detectors placed 14 milliradians off-axis to the NuMI beam. Charged current neutrino interactions will be used to observe the neutrino flavor from identification of the final state lepton. Reconstruction of muon charged particle tracks plays an important role in both the short te…
The relatively large measured value of $θ_{13}$ has opened up the possibility of determining the neutrino mass hierarchy through earth matter effects. Amongst the current accelerator-based experiments only NOvA has a long enough baseline to observe earth matter effects. However, NOvA is plagued with uncertainty on the knowledge of the true value of $δ_{CP}$, and this could drastically reduce its sensitivity to the neutrino mass hierarchy. The earth matter effect on atmospheric neutrinos on the other hand is almost independent of $δ_{CP}$. The 50 kton magnetized Iron CALorimeter at the India-ba…
We propose the RES-NOVA project which will hunt neutrinos from core-collapse supernovae (SN) via coherent elastic neutrino-nucleus scattering (CE$ν$NS) using an array of archaeological lead (Pb) based cryogenic detectors. The high CE$ν$NS cross-section on Pb and the ultra-high radiopurity of archaeological Pb enable the operation of a high statistics experiment equally sensitive to all neutrino flavors with reduced detector dimensions in comparison with existing Neutrino Observatories, and easy scalability to larger detector volumes. RES-NOVA is planned to operate according to three phases wit…
Standard three-flavor neutrino oscillations have well explained by a wide range of neutrino experiments. However, the anomalous results, such as electron-antineutrino excess seen by LSND and MiniBooNE do not fit the three-flavor paradigm. This can be explained by an additional fourth flavor sterile neutrino at a larger scale than the existing three flavor neutrinos. The NOvA experiment consists of two finely segmented, liquid scintillator detectors operating 14 .6 mrad off-axis from the NuMI muon-neutrino beam. The Near Detector is located on the Fermilab campus, 1 km from the NuMI target, whi…
The NOvA experiment is an off-axis long-baseline neutrino oscillation experiment seeking to measure $ν_μ$ disappearance and $ν_{e}$ appearance in a $ν_μ$ beam originating at Fermilab. In addition to measuring the unoscillated neutrino spectra for the purposes of predicting the oscillated neutrino spectrum in the far detector, the 293-ton near detector also enables high-statistics investigation into neutrino scattering in numerous reaction channels. We discuss the various near detector analyses currently in progress, including inclusive measurements of both electron and muon neutrino charged-cu…
The NOvA project is a long-baseline neutrino experiment. It utilizes the NuMI neutrino beam at Fermilab and consists of two functionally-identical liquid scintillator filled detectors. The detectors are placed 14 milliradians off-axis from the beam and 810 km apart. A 209 ton prototype detector, the Near Detector On the Surface (NDOS), was built and began taking initial neutrino data in December 2010. NDOS is 110 milliradians off-axis from the NuMI beam and also records neutrinos from the Booster Neutrino Beam. As NDOS is in the commissioning phase, metrics are being developed to improve under…
In study of muon neutrino disappearance at 810 km, the NOvA experiment finds flavor mixing of the atmospheric sector to deviate from maximal ($\sin^2θ_{23} = 0.5$) by 2.6 $σ$. The result is in tension with the 295-km baseline measurements of T2K which are consistent with maximal mixing. We propose that $θ_{23}$ is in fact maximal, and that the disagreement is harbinger of environmentally-induced decoherence. The departure from maximal mixing can be accounted for by an energy-independent decoherence of strength $Γ= (2.3 \pm 1.1) \times 10^{-23}$ GeV.
We evaluate the probability of future neutrino oscillation facilities to discover leptonic CP violation and/or measure the neutrino mass hierarchy. We study how this probability is affected by positive or negative hints for these observables to be found at T2K and NOvA. We consider the following facilities: LBNE; T2HK; and the 10 GeV Neutrino Factory (NF10), and show how their discovery probabilities change with the running time of T2K and NOvA conditioned to their results. We find that, if after 15 years T2K and NOvA have not observed a 90% CL hint of CP violation, then LBNE and T2HK have les…
Determining Neutrino Mass Ordering with NOvA and Upcoming JUNO Measurements
Erciyes University（埃尔西耶斯大学）；Universidad del Atlantico（大西洋大学）；University of Mississippi（密西西比大学）；Fermi National Accelerator Laboratory（费米国家加速器实验室）；Joint Institute for Nuclear Research（苏联联合核研究所）；Universidad del Magdalena（马格达莱纳大学）；University of Sussex（萨塞克斯大学）；University of Cincinnati（辛辛那提大学）；University of Hyderabad（海德拉巴大学）；University of California at Irvine（加州大学尔湾分校）；University of Minnesota Twin Cities（明尼苏达大学双城分校）
We present the most recent 3-flavor neutrino oscillation results from the NOvA long-baseline experiment, using a joint fit of $ν_μ\to ν_μ$, $\barν_μ \to \barν_μ$, $ν_μ\to ν_{e}$, and $\barν_μ\to \barν_{e}$ channels, and an accumulated exposure of $13.6 \times 10^{20}$ protons-on-target of neutrino beam and $12.5 \times 10^{20}$ protons-on-target of antineutrino beam. The best-fit values for the atmospheric parameters are $Δm^2_{32} = (2.41\pm0.07)\times 10^{-3}$ eV$^2$, $\sin^2θ_{23} = 0.57^{+0.03}_{-0.04}$ and $δ_{CP} = (0.82^{+0.27}_{-0.87}) π$. The data disfavor combinations of oscillation …
Following the precise measurement of $θ_{13}$ by reactor experiments three main questions remain within the now standard picture of neutrino oscillations: (1) Is the value of $θ_{23}$ such that the $ν_3$ state contains more muon flavor, more tau flavor, or equal amounts? (2) What is the neutrino mass hierarchy? (3) Is CP violated in the neutrino sector? The NOvA experiment will address all three of these questions. In each case the measurements are statistics limited motivating exploration of what could be accomplished with additional exposure.
NOvA is a long-baseline neutrino oscillation experiment. It is optimized to measure $ν_e$ appearance and $ν_μ$ disappearance at the Far Detector in the $ν_μ$ beam produced by the NuMI facility at Fermilab. NOvA uses a convolutional neural network (CNN) to identify neutrino events in two functionally identical liquid scintillator detectors. A different network, called prong-CNN, has been used to classify reconstructed particles in each event as either lepton or hadron. Within each event, hits are clustered into prongs to reconstruct final-state particles and these prongs form the input to this …
Detection of high-energy (~> 100 MeV) gamma rays by the Fermi Large Area Telescope (LAT) from a nova in the symbiotic binary system V407 Cygni has opened possibility of high-energy neutrino detection from this type of sources. Thermonuclear explosion on the white dwarf surface sets off a nova shell in motion that expands and slows down in a dense surrounding medium provided by the red giant companion. Particles are accelerated in the shocks of the shell, and interact with surrounding medium to produce observed gamma rays. We show that proton-proton interaction, which is most likely responsible…
NOvA is a long-baseline neutrino oscillation experiment with two functionally identical liquid scintillator tracking detectors, i.e. the Near Detector (ND) and the Far Detector (FD). One of NOvA's physics goal is to measure neutrino oscillation parameters by studying $ν_e$ appearance and $ν_μ$ disappearance with the Neutrinos at the Main Injector (NuMI) beam at Fermi National Accelerator Laboratory. An accurate light model is a prerequisite for precise charged particle energy estimation in the detectors. Particle energy is needed in event reconstruction and classification, both of which are cr…
In neutrino experiments, neutrino energy reconstruction is crucial because neutrino oscillations and differential cross-sections are functions of neutrino energy. It is also challenging due to the complexity in the detector response and kinematics of final state particles. We propose a regression Convolutional Neural Network (CNN) based method to reconstruct electron neutrino energy and electron energy in the NOvA neutrino experiment. We demonstrate that with raw detector pixel inputs, a regression CNN can reconstruct event energy even with complicated final states involving lepton and hadrons…
We examine the prospects of probing nonstandard interactions (NSI) of neutrinos in the e-tau sector with upcoming long-baseline nu_mu -> nu_e oscillation experiments. First conjectured decades ago, neutrino NSI remain of great interest, especially in light of the recent 8B solar neutrino measurements by SNO, Super-Kamiokande, and Borexino. We observe that the recent discovery of large theta_13 implies that long-baseline experiments have considerable NSI sensitivity, thanks to the interference of the standard and new physics conversion amplitudes. In particular, in some parts of NSI parameter s…
We describe the Library Event Matching classification algorithm implemented for use in the NOvA $ν_μ\rightarrow ν_e$ oscillation measurement. Library Event Matching, developed in a different form by the earlier MINOS experiment, is a powerful approach in which input trial events are compared to a large library of simulated events to find those that best match the input event. A key feature of the algorithm is that the comparisons are based on all the information available in the event, as opposed to higher-level derived quantities. The final event classifier is formed by examining the details …
The next galactic core-collapse supernova will deliver a wealth of neutrinos which for the first time we are well-situated to measure. These explosions produce neutrinos with energies between 10 and 100 MeV over a period of tens of seconds. Galactic supernovae are relatively rare events, occurring with a frequency of just a few per century. It is therefore essential that all neutrino detectors capable of detecting these neutrinos are ready to trigger on this signal when it occurs. This poster describes a data-driven trigger which is designed to detect the neutrino signal from a galactic core-c…
The NO$ν$A experiment is a long-baseline accelerator based neutrino oscillation experiment. It uses the upgraded Fermilab NuMI beam and measures electron-neutrino appearance and muon-neutrino disappearance at its far detector in Ash River, Minnesota. Goals of the experiment include measurements of $θ_{13}$, the neutrino-mass hierarchy and the CP-violating phase. NO$ν$A has begun to take data this year and will have its first physics results in 2014. This talk provides an overview of the scientific reach of the NO$ν$A experiment, the status of detector construction and physics analysis and a fi…
NOvA is a long-baseline neutrino oscillation experiment. It uses the NuMI beam from Fermilab and two sampling calorimeter detectors located off-axis from the beam. The NOvA experiment measures the rate of electron-neutrino appearance in the almost pure muon-neutrino NuMI beam, with the data measured at the Near Detector being used to accurately determine the expected rate at the Far Detector. It is very important to have automated and accurate monitoring of the data recorded by the detectors so any hardware, DAQ or beam issues arising in the 344k (20k) channels of the Far (Near) detector which…
The physics goals of NOvA are the constraints of neutrino oscillation parameters such as the octant of $θ_{23}$, $δ_{\rm{CP}}$, and the neutrino mass hierarchy via a joint fit to $ν_μ$ and $ν_{e}$ oscillation spectrum. We do this by propagating $ν_μ$ from the world's most intense neutrino beam at Fermilab, over a baseline of 810 km to northern Minnesota, USA, and measure the $ν_μ$ to $ν_{e}$ oscillation probability. NOvA announced its latest oscillation results, based on 8.85$\times10^{20}$ (6.9$\times10^{20}$) protons on target neutrino (antineutrino) data. Preliminary results for the allowed…
NOvA Dual-Baseline Search for Active-to-Sterile Neutrino Oscillations using Neutrino- and Antineutrino-Enriched Samples
Erciyes University（埃尔奇耶斯大学）；Universidad del Atlantico（大西洋大学）；University of Mississippi（密西西比大学）；Fermi National Accelerator Laboratory（费米国家加速器实验室）；Joint Institute for Nuclear Research（联合核研究所）；Universidad del Magdalena（马格达莱纳大学）；University of Sussex（萨塞克斯大学）；University of Cincinnati（辛辛那提大学）；University of California at Irvine（加州大学尔湾分校）；University of Hyderabad（海得拉巴大学）
One of the unknown parameters in neutrino oscillations is the octant of the mixing angle theta_{23}. In this paper, we discuss the possibility of determining the octant of theta_{23} in the long baseline experiments T2K and NOvA in conjunction with future atmospheric neutrino detectors, in light of non-zero value of theta_{13} measured by reactor experiments. We consider two detector technologies for atmospheric neutrinos - magnetized iron calorimeter and non-magnetized Liquid Argon Time Projection Chamber. We present the octant sensitivity for T2K/NOvA and atmospheric neutrino experiments sep…
The two-detector design of the NOvA neutrino oscillation experiment, in which two functionally identical detectors are exposed to an intense neutrino beam, aids in canceling leading order effects of cross-section uncertainties. However, limited knowledge of neutrino interaction cross sections still gives rise to some of the largest systematic uncertainties in current oscillation measurements. We show contemporary models of neutrino interactions to be discrepant with data from NOvA, consistent with discrepancies seen in other experiments. Adjustments to neutrino interaction models in GENIE that…
The measurement of a non-zero value of the 1-3 mixing angle has paved the way for the determination of leptonic CP violation. However the current generation long-baseline experiments T2K and NOvA have limited sensitivity to delta_{CP}. In this paper we show for the first time, the significance of that atmospheric neutrino experiments in providing the first hint of CP violation in conjunction with T2K and NOvA. In particular, we find that adding atmospheric neutrino data from the ICAL detector at the India-based Neutrino Observatory (INO) to T2K and NOvA results in a two-fold increase in the ra…
The MINOS experiment, operating in the NuMI beam since 2005, has provided the most precise measurement of the atmospheric mass splitting $|Δm^2_{32}|$, and the recent combination of the $ν_μ$, $ν_e$, and atmospheric neutrino samples has provided some evidence of non-maximal mixing, and hints about the neutrino mass hierarchy and the $θ_{23}$ octant. Construction of the NOvA experiment, situated off-axis in the upgraded NuMI beam, is almost complete. Over the coming years it will have significant power to probe the questions of the mass hierarchy, $θ_{23}$ octant, and the possibility of $\mathc…
We compare the physics potential of the upcoming neutrino oscillation experiments Daya Bay, Double Chooz, NOvA, RENO, and T2K based on their anticipated nominal luminosities and schedules. After discussing the sensitivity to theta_{13} and the leading atmospheric parameters, we demonstrate that leptonic CP violation will hardly be measurable without upgrades of the T2K and NOvA proton drivers, even if theta_{13} is large. In the presence of the proton drivers, the fast track to hints for CP violation requires communication between the T2K and NOvA collaborations in terms of a mutual synchroniz…
We study the impact of one light sterile neutrino on the prospective data expected to come from the two presently running long-baseline experiments T2K and NOvA when they will accumulate their full planned exposure. Introducing for the first time, the bi-probability representation in the 4-flavor framework, commonly used in the 3-flavor scenario, we present a detailed discussion of the behavior of the numu to nue and numubar to nuebar transition probabilities in the 3+1 scheme. We also perform a detailed sensitivity study of these two experiments (both in the stand-alone and combined modes) to…
Preliminary results of MINOS experiment indicate that theta23 is not maximal. Global fits to world neutrino data suggest two nearly degenerate solutions for theta23: one in the lower octant (LO: theta23 < 45 degree) and the other in the higher octant (HO: theta23 > 45 degree). numu to nue oscillations in superbeam experiments are sensitive to the octant and are capable of resolving this degeneracy. We study the prospects of this resolution by the current T2K and upcoming NOvA experiments. Because of the hierarchy-deltacp degeneracy and the octant-deltacp degeneracy, the impact of hierarchy on …
The purpose of this work is to examine the application of a deep learning model in event reconstruction of neutrino interactions. The challenges faced in event reconstruction include the placement of an accurate primary neutrino interaction vertex which is used to support the particle track and prong algorithms. The result of accurate primary vertex ensures all particles involved in a neutrino interaction are included. We propose a regression-based Convolutional Neural Network (CNN) method to predict the primary vertex of a particle interaction. We show that with raw two-dimensional pixel map …
Neutrino oscillations in matter provide a unique probe of new physics. Leveraging the advent of neutrino appearance data from NOvA and T2K in recent years, we investigate the presence of CP-violating neutrino non-standard interactions in the oscillation data. We first show how to very simply approximate the expected NSI parameters to resolve differences between two long-baseline appearance experiments analytically. Then, by combining recent NOvA and T2K data, we find a tantalizing hint of CP-violating NSI preferring a new complex phase that is close to maximal: $ϕ_{eμ}$ or $ϕ_{eτ}\approx3π/2$ …
NOvA (NuMI Off-axis νe Appearance) experiment is designed to study long-baseline neutrino oscillations using two detectors, the Near Detector (ND) at Fermilab and the Far Detector (FD) at a distance 810 km in Northern Minnesota. NOvA looks for the $ν_{e}$ appearance at the FD using a narrow band $ν_μ$ beam peaked at 2 GeV in energy. Neutral Current (NC) interactions with a $π^{0}$ in the final state represent the main background in the $ν_{e}$ appearance measurement. The $π^{0}$ decay into two photons can fake the $ν_{e}$ appearance signal in two ways either two photon showers merge together o…
