arXiv subjects

Pragyanprasu Swain

Publications and source records attributed to Pragyanprasu Swain.

6 recordsLinked to original sources

arXiv2026

Probing Neutrinophilic Long-Range Forces at DUNE

Neutrino oscillations provide compelling evidence for physics beyond the Standard Model, while the weakly interacting nature of neutrinos makes them powerful probes of new interactions and hidden sectors. In this work, we investigate a \textit{dark neutrino portal} scenario in which neutrino mass generation is linked to a light dark sector charged under a new $U(1)_D$ gauge symmetry. While Standard Model fields remain neutral under $U(1)_D$, the dark neutrino sector is charged and communicates with the Standard Model exclusively through active--dark neutrino mixing. The associated neutrinophilic mediator induces ultra-long-range interactions, whereby electrons and neutrons in the Earth, Moon, Sun, Milky Way, and the cosmological matter distribution generate sizable matter potentials that modify neutrino oscillations. We explore the sensitivity of the upcoming Deep Underground Neutrino Experiment (DUNE), whose long baseline and pronounced matter effects make it uniquely suited to probe such interactions. We show that DUNE can access previously unexplored regions of parameter space and demonstrate that the same underlying coupling can simultaneously give rise to sizable neutrino self-interactions, including regions relevant for alleviating the Hubble tension, while remaining consistent with current neutrino oscillation constraints.

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arXiv2026

Testing beyond the Standard Model scenarios in next-generation long-baseline neutrino oscillation experiments

In this thesis, we assess the sensitivity of next-generation long-baseline neutrino oscillation experiments, DUNE, T2HK, and T2HKK, to three popular beyond the Standard Model (BSM) scenarios. Within the three BSM studies, we examine: (i) long-range neutrino-matter interactions induced by flavor-dependent, anomaly-free gauged baryon-lepton symmetries mediated by ultra-light vector boson, showing that DUNE and T2HK can constrain, discover, and in some favorable cases distinguish among different symmetries; (ii) Lorentz invariance violation (LIV), where we derive analytical dependencies of CPT-conserving and CPT-violating LIV parameters on baseline and energy, highlighting the superior reach of DUNE in probing all the LIV parameters, in contrast to T2HK, which is essentially blind to the CPT-conserving LIV parameters; and (iii) active-sterile oscillations over a broad range of $Δm^2_{41}$, where we derive sensitivity to CP phases for benchmark choices of $Δm^2_{41}$ and establish exclusion limits, emphasizing the role of near detectors. Together, these studies show that future long-baseline facilities not only resolve the neutrino mass ordering, value of $δ_{\rm CP}$, and $θ_{23}$ octant, but also provide powerful probes of BSM physics.

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arXiv2025

A plethora of long-range neutrino interactions probed by DUNE and T2HK

The next-generation neutrino oscillation experiments would be sensitive to the new neutrino interactions that would strengthen the search for physics beyond the Standard Model. In this context, we explore the capabilities of the two leading future long-baseline neutrino oscillation experiments, DUNE and T2HK, to search for new flavor-dependent neutrino interactions with electrons, protons, and neutrons that could potentially modify neutrino flavor transitions. We forecast their sensitivities in the context of long-range neutrino interactions mediated by a neutral vector boson lighter than $10^{-10}$ eV and sourced by the vast amount of nearby and distant matter in the Earth, Moon, Sun, Milky Way, and local Universe. For the first time, we explore a plethora of $U(1)^\prime$ symmetries inducing the new interactions built from the combination of lepton and baryon numbers. We find that in all cases, DUNE and T2HK may constrain or discover the existence of new long-range neutrino interaction, and in some favorable cases, may identify the new $U(1)^\prime$ symmetry responsible for it. In this short proceeding, we only summarize the prospects of constraining the new interaction in case of all our candidate $U(1)^\prime$ symmetries, which have been discussed in JHEP 09 (2024) 055.

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arXiv2024

A plethora of long-range neutrino interactions probed by DUNE and T2HK

Upcoming neutrino experiments will soon search for new neutrino interactions more thoroughly than ever before, boosting the prospects of extending the Standard Model. In anticipation of this, we forecast the capability of two of the leading long-baseline neutrino oscillation experiments, DUNE and T2HK, to look for new flavor-dependent neutrino interactions with electrons, protons, and neutrons that could affect the transitions between different flavors. We interpret their sensitivity in the context of long-range neutrino interactions, mediated by a new neutral boson lighter than $10^{-10}$ eV, and sourced by the vast amount of nearby and distant matter in the Earth, Moon, Sun, Milky Way, and beyond. For the first time, we explore the sensitivity of DUNE and T2HK to a wide variety of $U(1)^\prime$ symmetries, built from combinations of lepton and baryon numbers, each of which induces new interactions that affect oscillations differently. We find ample sensitivity: in all cases, DUNE and T2HK may constrain the existence of the new interaction even if it is supremely feeble, may discover it, and, in some cases, may identify the symmetry responsible for it.

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arXiv2023

Constraining Lorentz Invariance Violation with Next-Generation Long-Baseline Experiments

Unified theories such as string theory and loop quantum gravity allow the Lorentz Invariance Violation (LIV) at the Planck Scale ($M_P \sim 10^{19}$ GeV). Using an effective field theory, this effect can be observed at low energies in terms of new interactions with a strength of $\sim 1/M_P$. These new interactions contain operators with LIV coefficients which can be CPT-violating or CPT-conserving. In this work, we study in detail how these LIV parameters modify the transition probabilities in the next-generation long-baseline experiments, DUNE and T2HK. We evaluate the sensitivities of these experiments in isolation and combination to constrain the off-diagonal CPT-violating ($a_{eμ}$, $a_{eτ}$, $a_{μτ}$) and CPT-conserving ($c_{eμ}$, $c_{eτ}$, $c_{μτ}$) LIV parameters. We derive approximate compact analytical expressions of $ν_μ\toν_e$ and $ν_μ\toν_μ$ probabilities in the presence of these LIV parameters to explain our numerical results. We explore the possible correlations and degeneracies between these LIV parameters & 3$ν$ parameters $θ_{23}$ & $δ_{\rm CP}$. We find that for non-maximal values of $θ_{23}$, there exist degenerate solutions in its opposite octant for standalone DUNE and T2HK. These degeneracies disappear when we combine the data from DUNE and T2HK. In case of no-show, we place the expected bounds on these CPT-violating and CPT-conserving LIV parameters at 95% C.L. using the standalone DUNE, T2HK, and their combination. We observe that due to its access to a longer baseline and high-energy neutrinos, DUNE has a better reach in probing all these LIV parameters as compared to T2HK. Since the terms containing the CPT-conserving LIV parameters are proportional to neutrino energy in oscillation probabilities, T2HK is almost insensitive to the CPT-conserving LIV parameters because it mostly deals with sub-GeV neutrinos.

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arXiv2021

Evolution of Neutrino Mass-Mixing Parameters in Matter with Non-Standard Interactions

We explore the role of matter effect in the evolution of neutrino oscillation parameters in the presence of lepton-flavor-conserving and lepton-flavor-violating neutral-current non-standard interactions (NSI) of the neutrino. We derive simple approximate analytical expressions showing the evolution/running of mass-mixing parameters in matter with energy in the presence of standard interactions (SI) and SI+NSI (considering both positive and negative values of real NSI parameters). We observe that only the NSI parameters in the (2,3) block, namely $\varepsilon_{μτ}$ and $(γ- β) \equiv (\varepsilon_{ττ} - \varepsilon_{μμ})$ affect the running of $θ_{23}$. Though all the NSI parameters influence the evolution of $θ_{13}$, $\varepsilon_{eμ}$ and $\varepsilon_{eτ}$ show a stronger impact at the energies relevant for DUNE. $θ_{12}$ quickly approaches to $\sim$ $90^{\circ}$ with increasing energy in both SI and SI+NSI cases. The change in $Δm^2_{21,m}$ is quite significant as compared to $Δm^2_{31,m}$ both in SI and SI+NSI frameworks. Flipping the signs of the NSI parameters alters the way in which mass-mixing parameters run with energy. We demonstrate the utility of our approach in addressing several important features related to neutrino oscillation such as: a) unraveling interesting degeneracies between $θ_{23}$ and NSI parameters, b) estimating the resonance energy in presence of NSI when $θ_{13}$ in matter becomes maximal, c) figuring out the required baselines and energies to have maximal matter effect in $ν_μ$ $\rightarrow$ $ν_{e}$ transition in the presence of different NSI parameters, and d) studying the impact of NSI parameters $\varepsilon_{μτ}$ and $(γ- β)$ on the $ν_μ \to ν_μ$ survival probability.

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