arXiv subjects

J Krishnamoorthi

Publications and source records attributed to J Krishnamoorthi.

5 recordsLinked to original sources

arXiv2026

$δ_{CP}$-free constraints on NSI parameters $\varepsilon_{eμ}$ and $\varepsilon_{eτ}$ using high-purity $ν_μ$ CC events at IceCube DeepCore

Atmospheric neutrinos provide a unique avenue to probe theories beyond the Standard Model (BSM) over a wide range of energies and path lengths. The theory of nonstandard interactions (NSI) of neutrinos is one of the important BSM scenarios, which can modify flavor oscillations of atmospheric neutrinos traveling through the Earth. In this work, we use a high-purity $ν_μ$ charged-current (CC) sample of atmospheric neutrinos from IceCube DeepCore with a livetime of 7.5 years to search for the NSI parameters $\varepsilon_{eμ}$, $\varepsilon_{eτ}$, and $\varepsilon_{ee}-\varepsilon_{μμ}$. The $ν_μ$ CC events mainly come from the $ν_μ$ survival channel having no significant dependence on $δ_{CP}$. Therefore, the constraints on $\varepsilon_{eμ}$ and $\varepsilon_{eτ}$ obtained using this $ν_μ$ CC sample are expected to be free from the $δ_{CP}$-degeneracy. The data sample is found to be in agreement with the standard neutrino interactions. Therefore, we place bounds on these NSI parameters that are consistent with and comparable to existing experimental constraints. These $δ_{CP}$-free constraints from IceCube DeepCore are complementary to those from the long-baseline neutrino oscillation experiments, where the appearance channel depends on $δ_{CP}$.

hep-ph↗

arXiv2026

Constraints on long-range neutrino interactions from a variety of $U(1)^\prime$ symmetries using atmospheric neutrinos at IceCube DeepCore

Neutrino oscillation experiments provide a unique probe to search for the physics beyond the Standard Model. In this work, we search for a broad class of anomaly-free flavor-dependent $U(1)^\prime$ symmetries using atmospheric neutrino data for the first time. Gauging these $U(1)^\prime$ symmetries give rise to ultra-light vector gauge bosons mediating long-range interactions (LRI) of neutrinos. These new interactions are sourced by the matter present in local and distant Universe, which can affect oscillations of neutrinos passing through the Earth. We use 8 years of high-purity $ν_μ$ charged-current neutrino events from IceCube DeepCore to search for these new interactions. We find no evidence for such new interactions in the data sample and place stringent constraints on the corresponding LRI potentials. These results are also translated as the bounds on the coupling strength and mass of mediator over their wide ranges for a plethora of $U(1)^\prime$ symmetries.

hep-ph↗

arXiv2026

Exploring Layered Structure Inside Earth Using Atmospheric Neutrino Oscillation at IceCube DeepCore

The IceCube detector, using its densely instrumented center, called DeepCore, can detect multi-GeV atmospheric neutrinos. The oscillation pattern of neutrinos is altered due to interactions with ambient electrons as they pass through Earth. The changes in these patterns are influenced by the amount of matter and its specific arrangement. As neutrinos propagate, they retain information about the densities they encounter. Our study demonstrates that IceCube DeepCore can utilize the Earth's matter effects to distinguish between a homogeneous matter density profile and a layered structure density profile of Earth. In this contribution, we present that IceCube DeepCore data equivalent to 9.3 years of observation can reject the homogeneous matter density profile with a confidence level of 1.4$σ$.

hep-ph↗

arXiv2026

First Constraints on Long-Range Neutrino Interactions using IceCube DeepCore

We present the first search for new flavor-dependent long-range interactions (LRI) of neutrinos using publicly available 8 years of high-purity $ν_μ$ CC data from IceCube DeepCore. These interactions are mediated by ultra-light gauge bosons with masses below $10^{-10}$ eV, which can arise due to a new lepton-number gauge symmetry, such as $L_e - L_μ$ or $L_e - L_τ$. These long-range interactions induce matter potential between neutrinos and abundant electrons present in distant astrophysical sources. These LRI potentials could modify neutrino oscillation probabilities. By probing the effects of LRI on atmospheric neutrino oscillations at IceCube DeepCore, we place world-leading constraints on the coupling strength of these interactions.

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arXiv2025

Stringent constraints on non-standard neutrino interactions using high-purity $ν_μ$ CC events in IceCube DeepCore

The neutral-current (NC) non-standard interactions (NSI) of neutrinos with fermions can modify the flavor oscillations of atmospheric neutrinos as they propagate through the Earth. We present constraints on the NC-NSI parameters $\varepsilon_{μτ}$ and $\varepsilon_{ττ}-\varepsilon_{μμ}$ (one at a time) using a high-purity sample of $ν_μ$ charged-current (CC) atmospheric neutrino events collected by IceCube DeepCore over 7.5 years of livetime. These two parameters significantly affect the $ν_μ$ disappearance channel for which this golden event sample is optimized by the IceCube Collaboration. The best fit to this dataset is consistent with no NSI hypothesis, and we place the most stringent constraints to date: $-\,0.0094 < \varepsilon_{μτ} < 0.0079$ and $-\,0.030 < \varepsilon_{ττ}-\varepsilon_{μμ} < 0.029$ at 90% confidence level.

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