About

Ed Kearns is a Professor and the Director of Undergraduate Studies in the Department of Physics at Boston University. His research focuses on neutrino physics and particle astrophysics, with specific interests including neutrino oscillation, nucleon decay, and the search for dark matter. He was deeply involved in the discovery of neutrino oscillation using atmospheric neutrinos, a breakthrough announced in 1998 based on the Super-K experiment in Japan, which was recognized with the Nobel Prize in Physics in 2015. Kearns continues to investigate atmospheric neutrinos with Super-K, exploring unknown parameters such as CP violation and mass ordering. His work also encompasses the search for baryon number violation through proton decay, a prediction of Grand Unified Theories, and indirect evidence of dark matter through neutrino detection. Since 2018, he has contributed to a major upgrade of the Super-K experiment, incorporating gadolinium to enhance neutron detection capabilities. Kearns is a member of the T2K experiment, studying neutrino oscillations with a neutrino beam aimed at the Super-K detector, and is involved in the EMPHATIC hadron production experiment at Fermilab to better understand neutrino production. His past research includes R&D for dark matter detection using liquid argon techniques, participation in the MACRO and K2K experiments, and contributions to the development of liquid argon TPCs. His work has earned him prestigious awards, including the Breakthrough Prize in Fundamental Physics in 2015 and the W.K.H. Panofsky Prize in 2021.

Research topics

• Physics
• Particle physics
• Nuclear physics
• Astronomy
• Computer Science
• Astrophysics
• Machine Learning
• Artificial Intelligence
• Optics
• Systems engineering
• Environmental science
• Algorithm
• Geology
• Earth science
• Quantum mechanics
• Engineering

Selected publications

• Development of Faster and More Accurate Supernova Localization at Super-Kamiokande

  HAL (Le Centre pour la Communication Scientifique Directe) · 2026-04-09

  preprintOpen access

  The next nearby core-collapse supernova (SN) promises to yield a treasure of scientific information through multi-messenger astronomy. Early observations of the shock breakout (SBO) emissions are especially critical to understand the SN explosive mechanism as well as the properties of the progenitor star. Neutrino observatories are able to provide an early alert of a SN before the arrival of the SBO radiation. Super-Kamiokande (SK) has the unique capability to independently reconstruct an accurate SN pointing direction as part of its real-time monitoring system, ``SNWATCH.'' Recent upgrades to SK by adding gadolinium (Gd) to the detection volume have been accompanied by efforts to improve the speed and accuracy of SN direction reconstruction. A new, novel HEALPix-based approach (``HP-Fitter'') can calculate the SN direction from the reconstructed burst event directions in less than one second. As well, the previous maximum-likelihood direction fitter (``ML-Fitter'') was upgraded by incorporating event information from Gd neutron-capture as well as using the HP-Fitter for the initial fit parameters and from code refactoring and optimization. The improved ML-Fitter has better angular resolution but direction reconstruction time is $\mathcal{O}$(sec). Together with improvements in burst detection and event reconstruction times, SNWATCH is now able to generate an SN alert with pointing information in about 90 seconds. These upgrades have been implemented at SK and integrated into a new automated system to provide GCN notices.

  PublisherOA PDFDOI

• Measurements of Pion and Muon Nuclear Capture at Rest on Argon in the LArIAT Experiment

  Physical Review Letters · 2025-04-01

  articleOpen access

  We report the measurement of the final-state products of negative pion and muon nuclear capture at rest on argon by the LArIAT experiment at the Fermilab Test Beam Facility. We measure a population of isolated MeV-scale energy depositions, or blips, in 296 LArIAT events containing tracks from stopping low-momentum pions and muons. The average numbers of visible blips are measured to be 0.74±0.19 and 1.86±0.17 near muon and pion track endpoints, respectively. The 3.6σ statistically significant difference in blip content between muons and pions provides the first demonstration of a new method of pion-muon discrimination in neutrino liquid argon time projection chamber experiments. LArIAT Monte Carlo simulations predict substantially higher average blip counts for negative muon (1.22±0.08) and pion (2.34±0.09) nuclear captures. We attribute this difference to geant4's inaccurate simulation of the nuclear capture process.

  PublisherDOI

• First Joint Oscillation Analysis of Super-Kamiokande Atmospheric and T2K Accelerator Neutrino Data

  Physical Review Letters · 2025-01-02 · 13 citations

  articleOpen access

  The Super-Kamiokande and T2K Collaborations present a joint measurement of neutrino oscillation parameters from their atmospheric and beam neutrino data. It uses a common interaction model for events overlapping in neutrino energy and correlated detector systematic uncertainties between the two datasets, which are found to be compatible. Using 3244.4 days of atmospheric data and a beam exposure of 19.7(16.3)×10^{20} protons on target in (anti)neutrino mode, the analysis finds a 1.9σ exclusion of CP conservation (defined as J_{CP}=0) and a 1.2σ exclusion of the inverted mass ordering.

  PublisherDOI

• Measurement of the branching ratio of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mi mathvariant="normal">N</mml:mi> <mml:mprescripts/> <mml:none/> <mml:mn>16</mml:mn> </mml:mmultiscripts> </mml:math> , <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mi mathvariant="normal">C</mml:mi> <mml:mprescripts/> <mml:none/> <mml:mn>15</mml:mn> </mml:mmultiscripts> </mml:math> , <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mi mathvariant="normal">B</mml:mi> <mml:mprescripts/> <mml:none/> <mml:mn>12</mml:mn> </mml:mmultiscripts> </mml:math> , and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mi mathvariant="normal">B</mml:mi> <mml:mprescripts/> <mml:none/> <mml:mn>13</mml:mn> </mml:mmultiscripts> </mml:math> isotopes through the nuclear muon capture reaction in the Super-Kamiokande detector

  Physical review. C · 2025-12-08 · 1 citations

  articleOpen access

  International audience

  PublisherOA PDFDOI

• Search for nucleon decay via $p\rightarrowνπ^{+}$ and $n\rightarrowνπ^{0}$ in 0.484 Mton-year of Super-Kamiokande data

  arXiv (Cornell University) · 2025-10-30

  preprintOpen access

  We present the results of searches for nucleon decays via $p\rightarrowνπ^{+}$ and $n\rightarrowνπ^{0}$ using a 0.484 Mt$\cdot$yr exposure of Super-Kamiokande I-V data covering the entire pure water phase of the experiment. Various improvements on the previous 2014 nucleon decay search, which used an exposure of 0.173 Mt$\cdot$yr, are incorporated. The physics models related to pion production and nuclear interaction are refined with external data, and a more comprehensive set of systematic uncertainties, now including those associated with the atmospheric neutrino flux and pion production channels is considered. Also, the fiducial volume has been expanded by 21\%. No significant indication of a nucleon decay signal is found beyond the expected background. Lower bounds on the nucleon partial lifetimes are determined to be $3.5\times10^{32}$~yr for $p\rightarrowνπ^{+}$ and $1.4\times10^{33}$~yr for $n\rightarrowνπ^{0}$ at 90\% confidence level.

  PublisherOA PDFDOI

• Experimental investigation of longitudinal scraping of $H-$ bunches via photo-detachment

  2025-06-05

  reportOpen access

  Longitudinal emittance growth is a significant challenge in RF linacs, especially for poorly bunched beams. This stems from particles occupying outer synchrotron oscillation orbits in the LBET, causing unwanted bunch-bunch interactions and degraded beam quality. To address this, we proposed using temporally spaced laser pulses to selectively photo-detach electrons from the longitudinal head and tail regions of H- ion bunches. This approach aims to reduce particle density in extreme orbits, enhancing beam uniformity and limiting emittance growth. Our experiments employed Fermilab's 'LaserNotcher' system at the font end of the linac, delivering 1.6 MW peak power with sub-nanosecond precision. By neutralizing the first and last half-nanosecond of several H- bunches, we measured their propagation injection into the booster. Measurements of pulse width, average height, and temporal spacing over booster cycles were compared between the scraped and unscraped bunches. Statistical analysis evaluated the results’ significance, highlighting the feasibility of laser-based scraping for future linac designs to achieve higher beam energies with improved emittance control.

  PublisherOA PDFDOI

• First observation of antiproton annihilation at rest on argon in the LArIAT experiment

  Physical review. D/Physical review. D. · 2025-05-20 · 1 citations

  articleOpen access

  We report the first observation and measurement of antiproton annihilation at rest on argon track and shower multiplicities and particle identification conducted with the LArIAT experiment. Stopping antiprotons from the Fermilab Test Beam Facility’s charged particle test beam are identified using beamline instrumentation and LArIAT’s liquid argon time projection chamber (LArTPC). The charged particle multiplicity from the annihilation vertex is manually evaluated via hand scanning, yielding a mean of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mn>3.2</a:mn><a:mo>±</a:mo><a:mn>0.4</a:mn></a:math> tracks and a standard deviation of 1.3 tracks, consistent with a semiautomated reconstruction resulting in <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mn>2.8</c:mn><c:mo>±</c:mo><c:mn>0.4</c:mn></c:math> tracks and a standard deviation of 1.2 tracks. Both methods are consistent with Monte Carlo simulations within statistical uncertainty. The shower multiplicities and particle identification for outgoing tracks are also consistent with eant4 model predictions. These results, obtained from a low-statistics sample, provide a foundation for higher-statistics studies in larger LArTPCs, which could refine modeling of intranuclear annihilation on argon and inform scenarios such as neutron-antineutron oscillations.

  PublisherOA PDFDOI

• Search for neutron decay into an antineutrino and a neutral kaon in 0.401 megaton-years exposure of Super-Kamiokande

  Physical review. D/Physical review. D. · 2025-11-07 · 1 citations

  preprintOpen access

  We searched for bound neutron decay via <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mi>n</a:mi> <a:mo stretchy="false">→</a:mo> <a:mover accent="true"> <a:mi>ν</a:mi> <a:mo stretchy="false">¯</a:mo> </a:mover> <a:mo>+</a:mo> <a:msup> <a:mi>K</a:mi> <a:mn>0</a:mn> </a:msup> </a:math> predicted by the grand unified theories in <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" display="inline"> <f:mrow> <f:mn>0.401</f:mn> <f:mtext> </f:mtext> <f:mtext> </f:mtext> <f:mi>Mton</f:mi> <f:mo>·</f:mo> <f:mi>years</f:mi> </f:mrow> </f:math> exposure of all pure water phases in the Super-Kamiokande detector. About 4.4 times more data than in the previous search have been analyzed by a new method including a spectrum fit to kaon invariant mass distributions. No significant data excess has been observed in the signal regions. As a result of this analysis, we set a lower limit of <h:math xmlns:h="http://www.w3.org/1998/Math/MathML" display="inline"> <h:mn>7.8</h:mn> <h:mo>×</h:mo> <h:msup> <h:mn>10</h:mn> <h:mn>32</h:mn> </h:msup> <h:mtext> </h:mtext> <h:mtext> </h:mtext> <h:mi>years</h:mi> </h:math> on the neutron lifetime at a 90% confidence level.

  PublisherOA PDFDOI

• Measurement of neutron production in atmospheric neutrino interactions at Super-Kamiokande

  Physical review. D/Physical review. D. · 2025-06-23 · 5 citations

  articleOpen access

  We present measurements of total neutron production from atmospheric neutrino interactions in water, analyzed as a function of electron-equivalent visible energy over a range of 30 MeV to 10 GeV. These results are based on 4,270 days of data collected by Super-Kamiokande, including 564 days with 0.011 wt% gadolinium added to enhance neutron detection. Neutron signal selection is based on a neural network trained on simulation, with its performance validated using an Am/Be neutron point source. The measurements are compared to predictions from neutrino event generators combined with various hadron-nucleus interaction models, which include an intranuclear cascade model and a nuclear deexcitation model. We observe significant variations in the predictions depending on the choice of hadron-nucleus interaction model. We discuss key factors that contribute to describing our data, such as in-medium effects in the intranuclear cascade and the accuracy of statistical evaporation modeling.

  PublisherDOI

• Data Release: Measurement of neutron production in atmospheric neutrino interactions at Super-Kamiokande

  White Rose Research Online (University of Leeds, The University of Sheffield, University of York) · 2025-05-07

  preprintOpen access

  This data release accompanies the article ["Measurement of neutron production in atmospheric neutrino interactions at Super-Kamiokande"](https://arxiv.org/abs/2505.04409). The data provided here includes observed average neutron multiplicity in atmospheric neutrino interactions at Super-Kamiokande (SK) as a function of the event's visible energy, along with model predictions using various combinations of final-state interaction (FSI) models and secondary hadron interaction models. For details on the data selection and compared models, please refer to the associated article on [arXiv](https://arxiv.org/abs/2505.04409). Files Included: 1. `x_bin_edges.txt`:Contains the x bin edges for all data, formatted as a list, which is equivalent to `np.logspace(np.log10(30), 4, 51)` in `numpy`. The bin edges are common for all event types included in the two comma-delimited csv files below. 2. `data_observations.csv`:Contains the observed SK data. - `event_type`: (`all`, `sr`, `mr`) - `all`: All events that pass the selection criteria. - `sr`: Single-ring events only. - `mr`: Multi-ring events only. - `x_bin_id`: Bin ID to match between data observations and model predictions. - `x_bin_center`: Mean value of visible energy for events in the x bin. - `y_nmult_est`: Average estimated neutron multiplicity for events in the x bin. Data includes estimated y errors: - `yerr_total`: Total uncertainty for the observed `y_nmult_est`, calculated as the L2 norm of the following uncertainty components. - `yerr_stat`: Statistical uncertainty. - `yerr_effscale`: Systematic uncertainty due to uncertainty in neutron signal efficiency scale (assumed to be fully correlated across all bins) - `yerr_other`: Other systematic uncertainties (assumed to be independent and uncorrelated across bins) 3. `model_predictions.csv`:Contains various model predictions for comparison with the observed data. - `fsi_model`: FSI model used within neutrino event generators: (`"neut_5.4.0"`, `"neut_5.6.3"`, `"genie_ha"`, `"genie_hn"`, `"genie_bert"`, `"genie_incl"`) - `sec_model`: Secondary hadron-nucleus interaction model used within detector simulators: (`"sk45_default"`, `"sk6_default"`, `"g3_gcalor"`, `"g4_bert"`, `"g4_bert_pc"`, `"g4_incl_pc"`) ---

  PublisherOA PDFDOI

Frequent coauthors

• M. R. Vagins

  University of California, Irvine

  1308 shared

• Y. Takeuchi

  University of Regina

  1167 shared

• M. Nakahata

  The University of Tokyo

  1059 shared

• Y. Hayato

  1058 shared

• C. K. Jung

  Stony Brook University

  1040 shared

• Y. Suzuki

  Kobe University

  995 shared

• K. Scholberg

  977 shared

• C. W. Walter

  Duke University

  907 shared

Labs

• Ed Kearns LaboratoryPI

Education

• Ph.D., Physics

  Harvard University

  1990

• B.S., Physics

  M.I.T.

  1982

Awards & honors

• W.K.H. Panofsky Prize (2021)
• Breakthrough Prize in Fundamental Physics (2015)
• Fellow, American Physical Society (2008)