Research
For a complete list of over 1,800 publications (h-index: 222), see my INSPIRE profile.
My research program links searches for new particles beyond the Standard Model to the development of real-time analysis and data acquisition techniques needed to find them. My group has been a key leader of the collider dark matter search program. My group is using advances in machine learning to help remake trigger-level data processing, reconstruction, and data compression for the HL-LHC era, where storage needs will enter the exabyte regime. We are part of the OSU ATLAS group and affiliated with CCAPP. As members of the ATLAS Collaboration, we collaborate closely with colleagues from a wide variety of institutions worldwide.
My research, papers, presentations, and other documents are organized by topic.
Trigger-Level Analysis
I co-developed Trigger-Level Analysis at ATLAS in 2014, together with Caterina Doglioni. TLA records data directly from the trigger system, bypassing the standard event-building path and enabling physics analyses in kinematic regions that would otherwise be inaccessible due to bandwidth constraints. The first TLA physics result was published in 2018 (Phys. Rev. Lett. 121, 081801; 204 citations); I led this analysis as contact author, with postdoc Tolley and student Reynolds. The full Run 2 dijet TLA search followed in 2025 (Phys. Rev. D 112, 092015 with ~2.4 times as many events as the entire main ATLAS Run-2 dataset; I was co-editor, with contributions from Tolley, Reynolds, and Gekow).
My group participates in the ATLAS Run 4 TLA Task Force (Marco Montella co-chairs it), developing strategies for trigger-level analysis at the HL-LHC.
- Search for electroweak-scale dijet resonances using Trigger-Level Analysis with the ATLAS Detector
- Search for low-mass resonances decaying into two jets and produced in association with a photon or a jet
- Search for low-mass resonances decaying into two jets and produced in association with a photon using pp collisions at √s = 13 TeV
- Search for low-mass dijet resonances using trigger-level jets with the ATLAS detector in pp collisions at √s = 13 TeV
- Trigger-object Level Analysis with the ATLAS detector at the LHC: Summary and Perspectives
- Trigger level analysis technique in ATLAS for Run 2 and beyond
- Challenges and opportunities for trigger-level analyses
- A Search for New Physics using Trigger-Level Analysis with ATLAS
- CERN Courier: Trigger Level Analysis at ATLAS
- Alex Gekow, PhD 2025 — thesis includes the Run 3 dijet+ISR TLA search
- Bryan Reynolds, PhD 2021 — "ATLAS jet trigger performance in Run 2 and searching for new physics with trigger-level jets"
BSM Searches and the ATLAS Exotics Program
Since 2011, I have helped build the ATLAS Exotics and LHC dark matter search programs. I convened the ATLAS Jets+X (later JDM, now JMX) physics analysis subgroup (2012–2014), co-led the first dijet search at the 13 TeV energy frontier (Phys. Lett. B754, 2016), developed and chaired the ATLAS/CMS Dark Matter Forum (2014–2015), co-convened the ATLAS Astroparticle Forum (2015–2017), and created and co-chaired the LHC Dark Matter Working Group (2015–2018) as the first piece of a now-wider LHC BSM Working Group. Current searches in my group include dijet resonances, ISR+dijet, ISR+di-b-jet, and diphoton TLA signatures.
- Search for single vector-like B quark production and decay via B → bH in pp collisions at √s = 13 TeV
- Search for new phenomena in events with an energetic jet and missing transverse momentum
- Constraints on mediator-based dark matter and scalar dark energy models using √s = 13 TeV pp collision data
- Search for dark matter and other new phenomena in events with an energetic jet and large missing transverse momentum
- Search for new phenomena in dijet events using 37 fb⁻¹ of pp collision data
- Search for new phenomena in dijet mass and angular distributions from pp collisions at √s = 13 TeV
- Search for new phenomena in final states with an energetic jet and large missing transverse momentum using pp collisions at √s = 13 TeV
- Search for new phenomena in dijet angular distributions in pp collisions at √s = 8 TeV
- Search for new phenomena in the dijet mass distribution using pp collision data at √s = 8 TeV
- Search for new phenomena in photon+jet events collected in pp collisions at √s = 8 TeV
- The performance of missing transverse momentum reconstruction and its significance with the ATLAS detector
- The future of US particle physics — the Snowmass 2021 Energy Frontier report
- Report of the topical group on physics beyond the Standard Model at the Energy Frontier for Snowmass 2021
- Physics at a 100 TeV pp collider: beyond the Standard Model phenomena
- Searches for Dark Matter at ATLAS and CMS
- Searches for Dark Matter at ATLAS
- Searches for Dark Matter at ATLAS
- Natalie Harrison, PhD 2024 — "A search for low mass resonances decaying into two jets and produced in association with a photon and development of pattern recognition algorithms for identifying track candidates in the ATLAS ITk detector"
Dark Matter Search Strategy
Beyond individual searches, I have contributed to building the community framework for collider dark matter studies. As convener of the ATLAS/CMS Dark Matter Forum (2014–2015) and the LHC Dark Matter Working Group (2015–2018), I led the development of the simplified-model benchmarks and presentation conventions now standard across ATLAS, CMS, and the theory community. I was co-chair of the Collider Dark Matter subgroup of the American Physical Society's Snowmass 2021 decadal exercise.
An invited review surveying collider search strategies for dark matter within the broader context of direct detection and astrophysical probes.
A prioritized, compact set of dark matter simplified models to support the design of the LHC dark matter searches, accompanied by studies of the parameter space of these models and a repository of generator implementations.
- Dark Matter Searches at Colliders
- Dark matter benchmark models for early LHC Run-2 searches: Report of the ATLAS/CMS Dark Matter Forum
- Recommendations of the LHC DM Working Group: comparing LHC searches for heavy mediators of DM production
- Recommendations on presenting LHC searches for missing transverse energy signals using simplified s-channel models
- LHC Dark Matter Working Group: next-generation spin-0 dark matter models
- Simplified models for dark matter searches at the LHC
- DarkFlux: A new tool to analyze indirect-detection spectra of next-generation dark matter models
- Summarizing experimental sensitivities of collider experiments to dark matter models
- Displaying dark matter constraints from colliders with varying simplified model parameters
- Snowmass 2021 cross frontier report: Dark matter complementarity
- Snowmass 2021 dark matter complementarity report
- Boyu Gao (2021) — "Comparing experimental sensitivities of Dark Matter experiments"
- Isabelle John (2019) — "Study of Dark Matter Models in Astrophysics and Particle Physics"
- (In-)Direct Searches Complementarity + Interpretation
- The LHC Dark Matter Working Group
- Where is Dark Matter at the LHC?
- Dark Matter Searches at the LHC
Machine Learning for Trigger and Data Acquisition
Since 2020, my group has pursued machine-learning methods for trigger-level data processing and compression. Initial work focused on supervised autoencoder compression (with Honey Gupta, Google Summer of Code 2020, and undergraduate Sam Roberts). From 2020 to 2021 I co-supervised four Lund University bachelor's and master's students with Doglioni on ML-based data compression. These methods were benchmarked in the Dark Machines anomaly detection challenge (SciPost 2022).
Alex Gekow developed neural-network-based charged particle tracking algorithms for FPGA deployment as part of his PhD research. He demonstrated end-to-end ML tracking with layer classification, Gaussian hit prediction, and ambiguity resolution networks, presented results at international meetings (Connecting the Dots in 2023, the US ATLAS workshop in 2023, the APS March Meeting in 2025), contributed ML tracking work to the EF Tracking TDR Amendment (CERN-LHCC-2022-004) and the internal EF Tracking FPGA Technology Final Report (a four-year effort), and mentored Google Summer of Code students and undergraduate students on ML for data compression. Jacob Balek is writing an honors thesis on ML classifiers applied to ATLAS data, co-supervised with OSU Prof. Rajiv Venkatakrishnan.
- ATLAS TDAQ Phase-II Upgrade: EF Tracking FPGA Technology Final Report
- Charged particle tracking with machine learning on FPGAs
- The Dark Machines anomaly score challenge: benchmark data and model independent event classification for the Large Hadron Collider
- Trigger Level Tracking With Neural Networks on Heterogeneous Computing Systems
- Real Time Track Finding using Machine Learning at the HL-LHC
- Track Finding and Fitting with Neural Networks on Heterogeneous Computing Systems
- Future possibilities for non-standard analysis workflows (TLA, PEB) in Run 3 and Beyond
- Autoencoders for compression
- Discussion Panel on Anomaly Detection in New Physics Searches
- Machine learning based tracking at the trigger level (poster)
- Alex Gekow, PhD 2025 — thesis chapter on trigger-level tracking with neural networks
- Love Kildetoft (2021) — "Evaluation of float-truncation based compression techniques for the ATLAS jet trigger"
- Jessica Lastow (2021) — "Investigation of Autoencoders for Jet Images in Particle Physics"
- Eric Wallin (2020) — "Tests of Autoencoder Compression of Trigger Jets in the ATLAS Experiment"
- Eric Wulff (2020) — "Deep Autoencoders for Compression in High Energy Physics"
Trigger, Data Acquisition, and Real-Time Computing
I have led and contributed to teams in building real-time computing for ATLAS since 2009. This work spans two complementary areas: real-time tracking systems for the ATLAS trigger, and the computing infrastructure that supports them.
The Fast TracKer (FTK) was a hardware-based real-time tracking system for the ATLAS trigger. A full "slice" of the working system was deployed at ATLAS Point 1; I served as FTK-HLT Integration Coordinator (2018–2019). The FTK design was the inspiration for a more ambitious 4 MHz Hardware Track Trigger (HTT) for the HL-LHC, which I led from 2020 to 2022—an international effort across more than 20 institutes. The HTT design evolved into the Event Filter Tracking project. After four years of effort on FPGA pipelines, including the work by Alex Gekow (see machine-learning section), the ATLAS selected a CPU+GPU architecture for EF Tracking in March 2026.
- Charged particle tracking with machine learning on FPGAs
- The ATLAS Trigger System for LHC Run 3 and Trigger performance in 2022
- The ATLAS Fast TracKer system
- Operation of the ATLAS trigger system in Run 2
- Performance of the ATLAS trigger system in 2015
- The FastTracKer real time processor and its impact on muon isolation, tau, and b-jet online selections at ATLAS
- ATLAS TDAQ Phase-II Upgrade: EF Tracking FPGA Technology Final Report
- Technical Design Report for the Phase-II Upgrade of the ATLAS TDAQ System — Event Filter Tracking Amendment
- HEP community white paper on software trigger and event reconstruction
- A roadmap for HEP software and computing R&D for the 2020s
- Hardware Track Trigger
- The ATLAS Hardware Track Trigger design towards first prototypes
- Hough Transform pattern recognition for track finding at the ATLAS experiment at the LHC
- Natalie Harrison, PhD 2024 — thesis includes EF tracking pattern recognition and FPGA firmware development
The High-Granularity Timing Detector
From 2018–2019, I was co-lead editor (with Stefan Guindon) of the 352-page HGTD Technical Design Report and from 2017–2019 served as Trigger/DAQ/Luminosity (Readout & DAQ) coordinator (with Jonas Strandberg) for the HGTD. The HGTD is part of the first generation of 4-D tracking detectors and starting in 2030 will provide precision pico-second timing measurements at the HL-LHC to mitigate the effects of pile-up at high luminosity.
- Technical design report: A High-Granularity Timing Detector for the ATLAS Phase-II Upgrade
- Technical Proposal: A High-Granularity Timing Detector for the ATLAS Phase-II Upgrade
- A High-Granularity Timing Detector for the Phase-II upgrade of the ATLAS Calorimeter system: detector concept, design, and readout
Higgs Boson Discovery and Earlier Work
I contributed to the observation of the Higgs boson at ATLAS in 2012, working on the H→WW* analysis channel, and had the privilge of presenting the discovery at the BEACH2012 conference a month later. Earlier, at CDF, I worked on ZZ resonance searches, novel tracking algorithms and tracking software optimizations, and the operation of the CDF Run II Silicon Vertex Detector, including developing techniques to measure cumulative radiation damage and monitoring/diagnosis of low-level errors in its readout electronics.
- Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS Detector
- Search for the Standard Model Higgs boson in the H → WW(*) → ℓνℓν decay mode with 4.7 fb⁻¹ of ATLAS data at √s = 7 TeV
- Observation of a new resonance at ATLAS
- Operational experience, improvements, and performance of the CDF Run II Silicon Vertex Detector
- Search for new heavy particles decaying to ZZ→ℓℓℓℓ, ℓℓjj in pp̄ collisions at √s = 1.96 TeV
- Search for new heavy particles decaying to ZZ→ℓℓℓℓ, ℓℓjj in pp̄ collisions at √s = 1.96 TeV
- Chiral supergravitons interacting with a 0-Brane N-Extended NSR Super-Virasoro Group
- Observation of a New Narrow Resonance at ATLAS
- Higgs boson discovery seminars
- Non-SUSY Searches at the Tevatron
- Radiation Damage to the CDF Silicon Detectors
- Status and performance of the CDF Run II silicon detector
Research Group
Current Members
- Marco Montella (postdoctoral researcher, 2021–present)
Co-chair of the ATLAS Run 4 TLA Task Force; former co-convener of the ATLAS JMX physics subgroup. - Osip Surdutovich (graduate student, 2024–present)
2025 Riley GTA Award. - Jacob Balek (undergraduate, 2024–present)
Honors thesis on ML classifiers applied to ATLAS data, co-supervised with Prof. Rajiv Venkatakrishnan. Contributing to upcoming ATLAS publications. Selected for Physics Department summer REU program.
Former Postdoctoral Advisees
- Emma Tolley (2017–2020) — Co-convened the ATLAS Missing Transverse Energy group; invited speaker at ICHEP (Seoul). Now Assistant Professor of Physics, EPFL, Lausanne, Switzerland.
Doctoral Students (Dissertation Advisor)
- Alex Gekow, PhD 2025 — 2025 Breakthrough Prize in Fundamental Physics laureate. Developed neural-network-based tracking for FPGAs; presented at Connecting the Dots 2023, US ATLAS 2023, APS March Meeting 2025. Now data scientist at MORSE Corp.
- Natalie Harrison, PhD 2024 — 2025 Breakthrough Prize laureate. Invited to contribute at "The Future of High Energy Physics" conference, Aspen Center for Physics. Now postdoc at the University of Virginia.
- Bryan Reynolds, PhD 2021 — 2025 Breakthrough Prize laureate. Now Electromagnetic Engineer at Remcom.
Graduate Student Mentees (Project Advisor)
- Jessica Miears (2024–2025)
Selected Undergraduate Advisees
- Rishivarshil Nelakurti (2024–2025) — US ATLAS SUPER Award (2025). Recasting the ATLAS ISR+Dijet TLA in RIVET.
- Nick Bagby (2024) — Contributed photon identification studies to the upcoming dijet+ISR TLA paper. PhD student at Cornell starting fall 2026.
- Jayde Spiegel (2023–2025) — Calorimeter noise studies for TLA; contributed to upcoming ATLAS publications. Now PhD student at UC Santa Cruz.
- Sam Bellman (2022–2024) — A&S Honors Program Undergraduate Research Scholarship (Spring 2024, college-wide competition). Honors thesis. Selected for Physics Department summer REU. Now PhD student at University of Washington.
- Omar Kotrach (2022–2024) — Honors thesis: "Isolation studies with trigger level photons and jets with the ATLAS detector in pp collisions at √s = 13.6 TeV." Selected for Physics Department summer REU. Now PhD student at UC San Diego.
- Sam Roberts (2017-2019) — Contributed to the 2025 TLA paper (Phys. Rev. D 112, 092015). Selected for Physics Department summer REU. Now PhD student at UC Santa Cruz.
- Boyu Gao (2018-2021) — A&S Honors Program Undergraduate Research Scholarship (Spring 2021, college-wide competition). Contributed dark matter sensitivity studies to the European Strategy for Particle Physics update and to Snowmass 2021. Graduated with honors. Selected for Physics Department summer REU. Now PhD student at Duke University.
- Harrison Blake-Goszyk (~2020) — Astronaut Scholar. Now PhD student at Vanderbilt.
- Honey Gupta (2020, Google Summer of Code, IIT Madras) — GSoC project on autoencoder compression for HEP data.
- Santhusht Prasad (2020) — Now Design Engineer at Traton US.
- Ryan de los Santos (2021, NSF IRES internship via Stanford)— Now Ph.D. student in OSU CMS group.
- Josie Rose (2023) — Adapting autoencoder networks to an Alveo U250 FPGA. Now PhD student at Yale.
CERN and Fermilab Summer Students
- Joshua Ramette (2016, CERN/Michigan REU) — "Improving ATLAS Jet Measurements and Searches with Particle Information." PhD MIT '24, founder & CEO of Undermind.AI.
- Armin Fehr (2016, University of Bern) — "Triggering on W, Z Boson Jets"
- Zitan Guo (2015, Chung Chi College, Hong Kong) — "Simulation, selection and reconstruction of dark Z bosons"
- Roumaissa Zebida (2015, University of Oran, Algeria) — "A trigger for selecting long-lived particle decays"
- Navaratnam Navarajacumaran (2015, University of Yamanashi, Japan) — "Analyzing the Quality of Dijet Data"
- Kimmo Kotajarvi (2005, Fermilab, University of Helsinki) — Silicon tracker data quality monitoring
- Juha Laakko (2005, Fermilab, University of Helsinki) — Silicon tracker data quality monitoring
Lund University Co-Supervised Students
- Love Kildetoft (2021, bachelor's thesis) · Jessica Lastow (2021, master's thesis) · Eric Wallin (2020, bachelor's thesis) · Eric Wulff (2020, master's thesis) · Isabelle John (2019, master's thesis)
As members of the ATLAS Collaboration, we work closely with colleagues from dozens of institutions worldwide on physics analysis, trigger development, and detector upgrades.
Teaching
- Spring 2026Physics 5401H: Honors Advanced Electricity and Magnetism II
- Autumn 2025Physics 5400H: Honors Intermediate Electricity and Magnetism I
- Spring 2025Physics 2301: Intermediate Mechanics II
- Spring 2024Physics 2301: Intermediate Mechanics II
- Spring 2023Physics 2301: Intermediate Mechanics II
- Spring 2022Physics 1251H: Honors E&M, Waves, Quantum Mechanics, Thermodynamics
- Spring 2021Physics 1251H: Honors E&M, Waves, Quantum Mechanics, Thermodynamics
- Spring 2020Physics 1250: Mechanics, Thermodynamics, Waves
- Spring 2019Physics 3700: Experimental Physics Instrumentation and Data Analysis Lab
- Spring 2018Physics 1250: Mechanics, Thermodynamics, Waves
- Autumn 2017Physics 3700: Experimental Physics Instrumentation and Data Analysis Lab
I am co-leading one thrust of a nine-institution collaboration developing computational learning goals and implementation strategies for undergraduate physics, with departments as the unit of change.
Research Leadership
- 2025–26ATLAS Run 4 Trigger-Level Analysis Task Force
- 2025–26Co-Editor, ATLAS Exotics Physics Roadmap
- 2021–22Snowmass 2021 Energy Frontier Collider Dark Matter Convener & EF–CF Liaison
- 2020–22TDAQ Hardware Track Trigger Coordinator for the HL-LHC Upgrade
- 2018–19FTK-HLT Integration Coordinator
- 2018–19Co-Lead Editor, HGTD Technical Design Report
- 2017–19Trigger/DAQ/Luminosity Coordinator, High Granularity Timing Detector
- 2015–18LHC Dark Matter Working Group Convener
- 2015–17Co-Convener, ATLAS Astroparticle Forum
- 2014–15ATLAS/CMS Dark Matter Forum Convener
- 2012–14ATLAS Exotics Jets+X Physics Analysis Subgroup Convener
Professional Service & Broader Impacts
- 2025–Competencies and Skills Co-Lead, Computational Integration in Undergraduate Physics collaboration (~10 US institutions)
- 2024–26APS Career Mentoring Fellow
- 2025–26Organizing Committee, AHEAD Bootcamp at BNL (2025) and FAR AHEAD (2026)
- Reviewer for NSF, DOE, European Research Council
- Referee for Physical Review Letters, JHEP, European Physical Journal C, Journal of Instrumentation
- 2026CERN Courier article on ATLAS Trigger Level Analysis (January 2026)
Awards & Honors
2025 Breakthrough Prize in Fundamental Physics
Laureate along with the ATLAS, CMS, ALICE, and LHCb Collaborations
- 2021Physics Undergraduate Teaching Award, Ohio State
- 2019High Energy and Particle Physics Prize (CDF and D0 Collaborations), European Physical Society
- 2014Marie Skłodowska-Curie COFUND Fellowship, CERN
- 2013High Energy and Particle Physics Prize (ATLAS and CMS Collaborations), European Physical Society
Curriculum Vitae
My full CV includes complete publication lists, all presentations, detailed mentoring history, and service contributions.
Download CV (PDF)