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Browsing by Author "Pestes, Rebekah"

Now showing 1 - 5 of 5
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    CP-Violating Neutrino Nonstandard Interactions in Long-Baseline-Accelerator Data
    Denton, Peter B.; Gehrlein, Julia; Pestes, Rebekah (2021-02-04)
    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 nonstandard 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: phi(e mu) or phi(e tau) approximate to 3 pi/2 with vertical bar epsilon(e mu vertical bar) or vertical bar epsilon(e tau)vertical bar similar to 0.2. We then compare the results from long-baseline data to constraints from IceCube and COHERENT.
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    The impact of different parameterizations on the interpretation of CP violation in neutrino oscillations
    Denton, Peter B.; Pestes, Rebekah (2021-05-17)
    CP violation in the lepton mass matrix will be probed with good precision in upcoming experiments. The amount of CP violation present in oscillations can be quantified in numerous ways and is typically parameterized by the complex phase delta (PDG) in the standard PDG definition of the lepton mixing matrix. There are additional parameterizations of the lepton mixing matrix as well. Through various examples, we explore how, given the current data, different parameterizations can lead to different conclusions when working with parameterization dependent variables, such as delta. We demonstrate how the smallness of |U-e3| governs the scale of these results. We then demonstrate how delta can be misleading and argue that the Jarlskog is the cleanest means of presenting the amount of CP violation in the lepton sector. We also confirm that, among the different parameterizations considered, the standard PDG parameterization has a number of convenient features.
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    Interference between the atmospheric and solar oscillation amplitudes
    Huber, Patrick; Minakata, Hisakazu; Pestes, Rebekah (2020-05-12)
    We propose to detect the interference effect between the atmospheric-scale and solar-scale waves of neutrino oscillation, one of the key consequences of the three-generation structure of leptons. In vacuum, we show that there is a natural and general way of decomposing the oscillation amplitude into these two oscillation modes. The nature of the interference is cleanest in the (nu) over bar (e) disappearance channel, since it is free from the CP phase delta. We find that the upcoming JUNO experiment offers an ideal setting to observe this interference with more than 4 sigma significance, even under conservative assumptions about the systematic uncertainties. Finally, we discuss the relationship between the mass-ordering resolution and the interference effect.
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    Neutrino oscillations at JUNO, the Born rule, and Sorkin's triple path interference
    Huber, Patrick; Minakata, Hisakazu; Minic, Djordje; Pestes, Rebekah; Takeuchi, Tatsu (American Physical Society, 2022-06-10)
    We argue that neutrino oscillations at JUNO offer a unique opportunity to study Sorkin's triple path interference, which is predicted to be zero in canonical quantum mechanics by virtue of the Born rule. In particular, we compute the expected bounds on triple path interference at JUNO and demonstrate that they are comparable to those already available from electromagnetic probes. Furthermore, the neutrino probe of the Born rule is much more direct due to an intrinsic independence from any boundary conditions, whereas such dependence on boundary conditions is always present in the case of electromagnetic probes. Thus, neutrino oscillations present an ideal probe of this aspect of the foundations of quantum mechanics.
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    Neutrino oscillations through the Earth's core
    Denton, Peter B.; Pestes, Rebekah (American Physical Society, 2021-12-29)
    Neutrinos have two properties that make them fairly unique from other known particles: extremely low cross sections and flavor changing oscillations. With a good knowledge of the oscillation parameters soon in hand, it will become possible to detect low-energy atmospheric neutrinos sensitive to the forward elastic scattering off electrons in the Earth's core providing a measurement of the core properties and the matter effect itself. As the dynamics of the Earth's core are complicated and in a difficult to probe environment, additional information from upcoming neutrino experiments will provide feedback into our knowledge of geophysics as well as useful information about exoplanet formation and various new physics scenarios including dark matter. In addition, we can probe the existence of the matter effect in the Earth and constrain the nonstandard neutrino interaction parameter epsilon circle plus ee. We show how DUNE's sensitivity to low-energy atmospheric neutrino oscillations can provide a novel constraint on the density and radius of the Earth's core at the 9% level and the Earth's matter effect at the 5% level. Finally, we illuminate the physics behind low-energy atmospheric neutrino resonances in the Earth.