Radio pulses generated by cosmic-ray air showers can be used to reconstruct key properties like the energy and depth of the electromagnetic component of cosmic-ray air showers. Radio detection threshold, influenced by natural and anthropogenic radio background, can be reduced through various techniques. In this work, we demonstrate that convolutional neural networks (CNNs) are an effective way to lower the threshold. We developed two CNNs: a classifier to distinguish radio signal waveforms from background noise and a denoiser to clean contaminated radio signals. Following the training and testing phases, we applied the networks to air-shower data triggered by scintillation detectors of the prototype station for the enhancement of IceTop, IceCube’s surface array at the South Pole. Over a four-month period, we identified 554 cosmic-ray events in coincidence with IceTop, approximately five times more compared to a reference method based on a cut on the signal-to-noise ratio. Comparisons with IceTop measurements of the same air showers confirmed that the CNNs reliably identified cosmic-ray radio pulses and outperformed the reference method. Additionally, we find that CNNs reduce the false-positive rate of air-shower candidates and effectively denoise radio waveforms, thereby improving the accuracy of the power and arrival time reconstruction of radio pulses.

United States

R. Abbasi

Germany

M. Ackermann

New Zealand

J. Adams

S.K. Agarwalla

Belgium

J.A. Aguilar

Denmark

M. Ahlers

J.M. Alameddine

S. Ali

N.M. Amin

K. Andeen

C. Argüelles

Y. Ashida

S. Athanasiadou

S.N. Axani

R. Babu

X. Bai

J. Baines-Holmes

A. Balagopal V.

S.W. Barwick

S. Bash

V. Basu

R. Bay

J.J. Beatty

J. Becker Tjus

P. Behrens

Sweden

J. Beise

C. Bellenghi

B. Benkel

S. BenZvi

D. Berley

Italy

E. Bernardini

D.Z. Besson

E. Blaufuss

L. Bloom

S. Blot

I. Bodo

F. Bontempo

J.Y. Book Motzkin

C. Boscolo Meneguolo

S. Böser

O. Botner

J. Böttcher

J. Braun

B. Brinson

Canada

Z. Brisson-Tsavoussis

Australia

R.T. Burley

D. Butterfield

M.A. Campana

K. Carloni

J. Carpio

S. Chattopadhyay

N. Chau

Z. Chen

D. Chirkin

S. Choi

B.A. Clark

A. Coleman

P. Coleman

G.H. Collin

D.A. Coloma Borja

A. Connolly

J.M. Conrad

R. Corley

D.F. Cowen

C. De Clercq

J.J. DeLaunay

D. Delgado

T. Delmeulle

S. Deng

P. Desiati

K.D. de Vries

G. de Wasseige

T. DeYoung

J.C. Díaz-Vélez

S. DiKerby

M. Dittmer

A. Domi

L. Draper

L. Dueser

D. Durnford

K. Dutta

M.A. DuVernois

T. Ehrhardt

L. Eidenschink

A. Eimer

P. Eller

E. Ellinger

D. Elsässer

R. Engel

H. Erpenbeck

W. Esmail

S. Eulig

J. Evans

P.A. Evenson

K.L. Fan

K. Fang

Japan

K. Farrag

A.R. Fazely

Taiwan

A. Fedynitch

N. Feigl

Identification and denoising of radio signals from cosmic-ray air showers using convolutional neural networks

The IceCube Upgrade is an extension of the existing IceCube Neutrino Observatory and will be deployed in the 2025–2026 austral summer. It will significantly improve the sensitivity of the detector to atmospheric neutrino oscillations. The existing 86-string IceCube array contains a dense in-fill known as DeepCore which is optimized to measure neutrinos with energies down to a few GeV. The IceCube Upgrade will consist of seven new densely instrumented strings placed within the DeepCore volume to further enhance the performance in the GeV energy range. The additional strings will feature new optical modules, each containing multiple photomultiplier tubes (PMTs), in contrast to the existing modules that each contain a single PMT. This will more than triple the number of PMT channels with respect to the current IceCube configuration, allowing for improved detection efficiency and reconstruction performance at GeV energies. We describe necessary updates to simulation, event selection, and reconstruction to accommodate the higher data rates observed by the upgraded detector and the addition of multi-PMT modules. We determine the expected sensitivity of the IceCube Upgrade to the atmospheric neutrino oscillation parameters <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>sin</mi></mrow><mrow><mn>2</mn></mrow></msup><msub><mrow><mi>θ</mi></mrow><mrow><mn>23</mn></mrow></msub></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Δ</mi><msubsup><mi>m</mi><mn>32</mn><mn>2</mn></msubsup></math>, the appearance of tau neutrinos and the neutrino mass ordering. The IceCube Upgrade will provide neutrino oscillation measurements that are of similar precision to those from accelerator experiments, while providing complementarity by probing higher energies and longer baselines, and with different sources of systematic uncertainties.

Physics potential of the IceCube Upgrade for atmospheric neutrino oscillations

We present a measurement of the mean number of muons with energies larger than 500 GeV in near-vertical extensive air showers initiated by cosmic rays with primary energies between 2.5 and 100 PeV. The measurement is based on events detected in coincidence between the surface and in-ice detectors of the IceCube Neutrino Observatory. Air showers are recorded on the surface by IceTop, while a bundle of high-energy muons (TeV muons) from the shower can subsequently produce a tracklike event in the IceCube in-ice array. Results are obtained assuming the hadronic interaction models Sibyll 2.1, QGSJet-II.04, and EPOS-LHC. The measured number of TeV muons is found to be in agreement with predictions from air-shower simulations. The results have also been compared to a measurement of low-energy muons by IceTop, indicating an inconsistency between the predictions for low- and high-energy muons in simulations based on the EPOS-LHC model.

C. Finley

L. Fischer

Measurement of the mean number of muons with energies above 500 GeV in air showers detected with the IceCube Neutrino Observatory

We report a study of the inelasticity distribution in the scattering of neutrinos of energy 80–560 GeV off nucleons. Using atmospheric muon neutrinos detected in IceCube’s sub-array DeepCore during 2012–2021, we fit the observed inelasticity in the data to a parameterized expectation and extract the values that describe it best. Finally, we compare the results to predictions from various combinations of perturbative QCD calculations and atmospheric neutrino flux models.

M. Baricevic

J. Brostean-Kaiser

L. Brusa

I. Caracas

South Korea

A. Desai

A. Diaz

P. Dierichs

H. Dujmovic

S. El Mentawi

S. Fiedlschuster

Measurement of the inelasticity distribution of neutrino-nucleon interactions for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>80</mn><mtext> </mtext><mi>GeV</mi><mo>&lt;</mo><msub><mrow><mi mathvariant="normal">E</mi></mrow><mrow><mi>ν</mi></mrow></msub><mo>&lt;</mo><mn>560</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></math> with IceCube DeepCore

The DeepCore subdetector of the IceCube Neutrino Observatory provides access to neutrinos with energies above approximately 5 GeV. Data taken between 2012 and 2021 (3387 days) are utilized for an atmospheric <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>μ</mi></msub></math> disappearance analysis that studied 150 257 neutrino-candidate events with reconstructed energies between 5 and 100 GeV. An advanced reconstruction based on a convolutional neural network is applied, providing increased signal efficiency and background suppression, resulting in a measurement with both significantly increased statistics compared to previous DeepCore oscillation results and high neutrino purity. For the normal neutrino mass ordering, the atmospheric neutrino oscillation parameters and their <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1</mn><mi>σ</mi></mrow></math> errors are measured to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">Δ</mi><msubsup><mrow><mi mathvariant="normal">m</mi></mrow><mrow><mn>32</mn></mrow><mrow><mn>2</mn></mrow></msubsup><mo>=</mo><msubsup><mrow><mn>2.40</mn></mrow><mrow><mo>−</mo><mn>0.04</mn></mrow><mrow><mo>+</mo><mn>0.05</mn></mrow></msubsup><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup><mtext> </mtext><mtext> </mtext><msup><mrow><mi>eV</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>sin</mi></mrow><mrow><mn>2</mn></mrow></msup><msub><mrow><mi>θ</mi></mrow><mrow><mn>23</mn></mrow></msub><mo>=</mo><msubsup><mrow><mn>0.54</mn></mrow><mrow><mo>−</mo><mn>0.03</mn></mrow><mrow><mo>+</mo><mn>0.04</mn></mrow></msubsup></mrow></math>. The results are the most precise to date using atmospheric neutrinos, and are compatible with measurements from other neutrino detectors including long-baseline accelerator experiments.

G. Anton

L. Ausborm

C. Benning

E. Bourbeau

P. Coppin

P. Correa

P. Dave

Measurement of Atmospheric Neutrino Oscillation Parameters Using Convolutional Neural Networks with 9.3 Years of Data in IceCube DeepCore

We present the first three-parameter fit to a 3+1 sterile neutrino model using 7.634 years of data from the IceCube Neutrino Observatory on <math><msub><mrow><mi>ν</mi></mrow><mrow><mi>μ</mi></mrow></msub><mo>+</mo><msub><mrow><mover><mrow><mi>ν</mi></mrow><mo>‾</mo></mover></mrow><mrow><mi>μ</mi></mrow></msub></math> charged-current interactions in the energy range 500–9976 GeV. Our analysis is sensitive to the mass-squared splitting between the heaviest and lightest mass state (<math><mi>Δ</mi><msubsup><mrow><mi>m</mi></mrow><mrow><mn>41</mn></mrow><mrow><mn>2</mn></mrow></msubsup></math>), the mixing matrix element connecting muon flavor to the fourth mass state (<math><mo>|</mo><msub><mrow><mi>U</mi></mrow><mrow><mi>μ</mi><mn>4</mn></mrow></msub><msup><mrow><mo>|</mo></mrow><mrow><mn>2</mn></mrow></msup></math>), and the element connecting tau flavor to the fourth mass state (<math><mo>|</mo><msub><mrow><mi>U</mi></mrow><mrow><mi>τ</mi><mn>4</mn></mrow></msub><msup><mrow><mo>|</mo></mrow><mrow><mn>2</mn></mrow></msup></math>). Predicted propagation effects in matter enhance the signature through a resonance as atmospheric neutrinos from the Northern Hemisphere traverse the Earth to the IceCube detector at the South Pole. The remaining sterile neutrino matrix elements are left fixed, with <math><mo>|</mo><msub><mrow><mi>U</mi></mrow><mrow><mi>e</mi><mn>4</mn></mrow></msub><msup><mrow><mo>|</mo></mrow><mrow><mn>2</mn></mrow></msup><mo>=</mo><mn>0</mn></math> and <math><msub><mrow><mi>δ</mi></mrow><mrow><mn>14</mn></mrow></msub><mo>=</mo><mn>0</mn></math>, as they have a negligible effect, and <math><msub><mrow><mi>δ</mi></mrow><mrow><mn>24</mn></mrow></msub><mo>=</mo><mi>π</mi></math> is set to give the most conservative limits. The result is consistent with the no-sterile neutrino hypothesis with a probability of 4.3%. Profiling the likelihood of each parameter yields the 90% confidence levels: <math><mn>2.4</mn><mspace width="0.2em"></mspace><msup><mrow><mi>eV</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>&lt;</mo><mi>Δ</mi><msubsup><mrow><mi>m</mi></mrow><mrow><mn>41</mn></mrow><mrow><mn>2</mn></mrow></msubsup><mo>&lt;</mo><mn>9.6</mn><mspace width="0.2em"></mspace><msup><mrow><mi>eV</mi></mrow><mrow><mn>2</mn></mrow></msup></math>, <math><mn>0.0081</mn><mo>&lt;</mo><mo>|</mo><msub><mrow><mi>U</mi></mrow><mrow><mi>μ</mi><mn>4</mn></mrow></msub><msup><mrow><mo>|</mo></mrow><mrow><mn>2</mn></mrow></msup><mo>&lt;</mo><mn>0.10</mn></math>, and <math><mo>|</mo><msub><mrow><mi>U</mi></mrow><mrow><mi>τ</mi><mn>4</mn></mrow></msub><msup><mrow><mo>|</mo></mrow><mrow><mn>2</mn></mrow></msup><mo>&lt;</mo><mn>0.035</mn></math>, which narrows the allowed parameter-space for <math><mo>|</mo><msub><mrow><mi>U</mi></mrow><mrow><mi>τ</mi><mn>4</mn></mrow></msub><msup><mrow><mo>|</mo></mrow><mrow><mn>2</mn></mrow></msup></math>. However, the primary result of this analysis is the first map of the 3+1 parameter space exploring the interdependence of <math><mi>Δ</mi><msubsup><mrow><mi>m</mi></mrow><mrow><mn>41</mn></mrow><mrow><mn>2</mn></mrow></msubsup></math>, <math><mo>|</mo><msub><mrow><mi>U</mi></mrow><mrow><mi>μ</mi><mn>4</mn></mrow></msub><msup><mrow><mo>|</mo></mrow><mrow><mn>2</mn></mrow></msup></math>, and <math><mo>|</mo><msub><mrow><mi>U</mi></mrow><mrow><mi>τ</mi><mn>4</mn></mrow></msub><msup><mrow><mo>|</mo></mrow><mrow><mn>2</mn></mrow></msup></math>.

A. Balagopal

Exploration of mass splitting and muon/tau mixing parameters for an eV-scale sterile neutrino with IceCube

We present a search for a neutrino signal from dark matter self-annihilations in the Milky Way using the IceCube Neutrino Observatory (IceCube). In 1005 days of data we found no significant excess of neutrinos over the background of neutrinos produced in atmospheric air showers from cosmic ray interactions. We derive upper limits on the velocity averaged product of the dark matter self-annihilation cross section and the relative velocity of the dark matter particles â¨ÏAvâ© . Upper limits are set for dark matter particle candidate masses ranging from 10Â GeV up to 1Â TeV while considering annihilation through multiple channels. This work sets the most stringent limit on a neutrino signal from dark matter with mass between 10 and 100Â GeV, with a limit of 1.18Â·10-23cm3s-1 for 100Â GeV dark matter particles self-annihilating via Ï+Ï- to neutrinos (assuming the NavarroâFrenkâWhite dark matter halo profile).

M.G. Aartsen

M. Ahrens

Switzerland

I. Al Samarai

D. Altmann

T. Anderson

I. Ansseau

J. Auffenberg

S. Axani

H. Bagherpour

J.P. Barron

V. Baum

K.H. Becker

G. Binder

D. Bindig

C. Bohm

M. Börner

F. Bos

D. Bose

J. Bourbeau

F. Bradascio

L. Brayeur

M. Brenzke

H.P. Bretz

S. Bron

A. Burgman

T. Carver

J. Casey

M. Casier

E. Cheung

A. Christov

K. Clark

L. Classen

S. Coenders

R. Cross

M. Day

J.P.A.M. de André

H. Dembinski

S. De Ridder

M. de With

V. di Lorenzo

J.P. Dumm

M. Dunkman

B. Eberhardt

B. Eichmann

S. Fahey

J. Felde

K. Filimonov

S. Flis

A. Franckowiak

E. Friedman

T. Fuchs

T.K. Gaisser

J. Gallagher

L. Gerhardt

K. Ghorbani

Search for neutrinos from dark matter self-annihilations in the center of the Milky Way with 3 years of IceCube/DeepCore