Philip Ilten

BS: Massachusetts Intitute of Technology Camridge, MA, USA, 2008 (Physics with a Minor in Music)

BS: Massachusetts Intitute of Technology Camridge, MA, USA, 2008 (Mathematics)

Diplom: George-August-Universitaet Goettingen, Germany, 2009 (Physics)

PhD: University College Dublin Dublin, Ireland, 2013 (High Energy Experimental Particle Physics)

PGCHE: University of Birmingham Birmingham, UK, 2020 (Higher Education)

My area of research is high energy physics (HEP), where we probe the interactions of what we believe to be fundamental particles. I work on both experiment and theory. Much of my work on experiment is with the LHCb detector, a large-scale HEP experiment on the Large Hadron Collider (LHC) located at the European Center for Nuclear Research (CERN) in Geneva, Switzerland. Here at UC, my group and I perform measurements that advance our understanding of quantum chromodynamics (QCD), the underlying theory of the strong force. We also search for new forms of matter which could explain the origin of dark matter, an unknown form of matter in the universe observed only via gravitational interactions. I am also the spokesperson for the Compact Detector for Exotics at LHCb (CODEX-b) collaboration, an LHCb-adjacent experiment which will also search for the origins of dark matter. With collaborators, my group at UC and CERN have built and installed CODEX-β, a small proof-of-concept demonstrator for CODEX-b.

Recently, I have focused my theory work on understanding hadronization, the process by which quarks and gluons combine into bound states, hadrons, like the proton and neutron. With Jure Zupan (UC), I founded the Machine Learning Hadronization (MLhad) group at UC which has expanded to include members at Fermilab and the University of Lund in Sweden. Our goal is to use machine learning (ML) and Monte Carlo (MC) techniques to explore hadronization. We have created the first ML hadronization model and demonstrated how ML hadronization models can be trained on data. As part of this work we implemented the first reweightable hadronization model in Pythia, opening up new methods for model tuning and uncertainty quantification. I am also a collaboration board member of Pythia, and a founding member of the Monte Carlo General Education Network (MCgen).

2008 -2008 software engineer, International Business Machines, Dublin, Ireland

2013 -2016 postdoctoral associate, Massachusetts Intitute of Technology, Cambridge, MA, USA

2016 -2017 senior postdoctoral associate, Massachusetts Intitute of Technology, Camridge, MA, USA

2017 -2020 Birmgham fellow/lecturer, University of Birmingham, Birmingham, UK

2020 -2021 senior Birmgham fellow/senior lecturer, University of Birmingham, Birmingham, UK

2020 -2023 assistant professor, University of Cincinnati, Cincinnati, OH, USA

2023 -2026 associate professor, University of Cincinnati, Cincinnati, OH, USA

2026 - professor, University of Cincinnati, Cincinnati, OH, USA

Grant: #OAC-2103889 Investigators:Ilten, Philip; Zupan, Jure 09-01-2021 -08-31-2024 National Science Foundation CSSI: Elements: Machine Learning Quark Hadronization Role:Co-PI $599,989 Completed Type:Grant

Grant: #PHY-2209769 Investigators:Ilten, Philip 07-01-2022 -06-30-2025 National Science Foundation Discovering True Muonium Role:PI $525,000 Completed

Grant: #OAC-2411215 Investigators:Ilten, Philip; Zupan, Jure 08-01-2024 -07-31-2027 National Science Foundation Elements: Automated parametric transformations for rapid particle physics simulations Role:Co-PI 599872.00 Active Type:Grant

Grant: #OAC-2417682 Investigators:Ilten, Philip; Mrenna, Steve; Zupan, Jure 09-15-2025 -08-31-2026 National Science Foundation Collaborative Research: CyberTraining: Pilot: Monte Carlo General Education Net- work (MCGEN) Role:Co-PI $139,998 Active Type:Grant

Grant: #DE-SC0026301 Investigators:Ilten, Philip; Mrenna, Steve; Zupan, Jure 09-29-2025 -06-03-2028 Department of Energy Training hadronization ML models on open data Role:Co-PI

Peer Reviewed Publications

Butter, Anja; others  (2025). Iterative HOMER with uncertainties.

Aielli, Giulio; others  (2025). CODEX-b: Opening New Windows to the Long-Lived Particle Frontier at the LHC: ESPP Update Comprehensive summary.

Assi, Beno\^\it; Bierlich, Christian; Ilten, Phil; Menzo, Tony; Mrenna, Stephen; Szewc, Manuel; Wilkinson, Michael K.; Youssef, Ahmed; Zupan, Jure  (2025). Post-hoc reweighting of hadron production in the Lund string model.

Assi, Beno\^\it; Bierlich, Christian; Ilten, Phil; Menzo, Tony; Mrenna, Stephen; Szewc, Manuel; Wilkinson, Michael K.; Youssef, Ahmed; Zupan, Jure  (2025). Characterizing the hadronization of parton showers using the HOMER method.

Heller, Nick; Ilten, Phil; Menzo, Tony; Mrenna, Stephen; Nachman, Benjamin; Siodmok, Andrzej; Szewc, Manuel; Youssef, Ahmed  (2024). Rejection Sampling with Autodifferentiation - Case study: Fitting a Hadronization Model.

Aaij, Roel; others  (2025). Measurements of $\psi (2S)$ and $\chi _c1(3872)$ production within fully reconstructed jets. Eur. Phys. J. C, 85 (5) , 562More Information

Bierlich, Christian; Ilten, Phil; Menzo, Tony; Mrenna, Stephen; Szewc, Manuel; Wilkinson, Michael K.; Youssef, Ahmed; Zupan, Jure  (2025). Describing hadronization via histories and observables for Monte-Carlo event reweighting. SciPost Phys., 18 (2) , 054More Information

Aielli, Giulio; others  (2025). Technical design report for the CODEX-\ensuremath\beta demonstrator. JINST, 20 (07) , T07007More Information

Cooke, Naomi; Ilten, Philip; L\"onnblad, Leif; Mrenna, Stephen  (2024). Non-relativistic quantum chromodynamics in parton showers. Eur. Phys. J. C, 84 (4) , 432More Information

Bierlich, Christian; Ilten, Phil; Menzo, Tony; Mrenna, Stephen; Szewc, Manuel; Wilkinson, Michael K.; Youssef, Ahmed; Zupan, Jure  (2024). Towards a data-driven model of hadronization using normalizing flows. SciPost Phys., 17 (2) , 045More Information

Bierlich, Christian; Ilten, Philip; Menzo, Tony; Mrenna, Stephen; Szewc, Manuel; Wilkinson, Michael K.; Youssef, Ahmed; Zupan, Jure  (2024). Reweighting Monte Carlo predictions and automated fragmentation variations in Pythia 8. SciPost Phys., 16 (5) , 134More Information

Aaij, Roel; others  (2024). The LHCb Upgrade I. JINST, 19 (05) , P05065More Information

Bose, Tulika; others  (2022). Report of the Topical Group on Physics Beyond the Standard Model at Energy Frontier for Snowmass 2021.More Information

Gori, Stefania; others  (2022). Dark Sector Physics at High-Intensity Experiments.

Baruch, Chaja; Ilten, Philip; Soreq, Yotam; Williams, Mike  (2022). Axial vectors in DarkCast. JHEP, 11, 124More Information

Ilten, Philip; others  (2022). Experiments and Facilities for Accelerator-Based Dark Sector Searches.

Bierlich, Christian; others  (2022). A comprehensive guide to the physics and usage of PYTHIA 8.3. SciPost Phys. Codeb., 2022, 8More Information

Campbell, J. M.; others  (2024). Event generators for high-energy physics experiments. SciPost Phys., 16 (5) , 130More Information

Abdullahi, Asli M.; others  (2023). The present and future status of heavy neutral leptons. J. Phys. G, 50 (2) , 020501More Information

Craik, Daniel; Ilten, Phil; Johnson, Daniel; Williams, Mike  (2022). LHCb future dark-sector sensitivity projections for Snowmass 2021.

Aielli, Giulio; others  (2022). The Road Ahead for CODEX-b.

Badger, Simon; others  (2023). Machine learning and LHC event generation. SciPost Phys., 14 (4) , 079More Information

Ilten, Phil; Menzo, Tony; Youssef, Ahmed; Zupan, Jure  (2023). Modeling hadronization using machine learning. SciPost Phys., 14 (3) , 027More Information

Aaij, Roel; others  (2022). Identification of charm jets at LHCb. JINST, 17 (02) , P02028More Information

Acosta, Darin; others  (2021). Review of opportunities for new long-lived particle triggers in Run 3 of the Large Hadron Collider.

Yazgan, Efe; others  (2021). HL-LHC Computing Review Stage-2, Common Software Projects: Event Generators.

Aaij, Roel; others  (2022). Study of Z Bosons Produced in Association with Charm in the Forward Region. Phys. Rev. Lett., 128 (8) , 082001More Information

Ilten, Philip; Utheim, Marius  (2022). Forming molecular states with hadronic rescattering. Eur. Phys. J. A, 58 (1) , 1More Information

Ilten, Philip  (2021). Probing QCD with LHCb. Int. J. Mod. Phys. A, 36 (21) , 2130011More Information

Borsato, M.; others  (2022). Unleashing the full power of LHCb to probe stealth new physics. Rept. Prog. Phys., 85 (2) , 024201More Information

Aarrestad, Thea; others  (2020). HL-LHC Computing Review: Common Tools and Community Software.More Information

Aaij, Roel; others  (2020). Searches for low-mass dimuon resonances. JHEP, 10, 156More Information

Amoroso, Simone; others  (2021). Challenges in Monte Carlo Event Generator Software for High-Luminosity LHC. Comput. Softw. Big Sci., 5 (1) , 12More Information

Abdallah, Waleed; others  (2020). Reinterpretation of LHC Results for New Physics: Status and Recommendations after Run 2. SciPost Phys., 9 (2) , 022More Information

Buckley, Andy; Ilten, Philip; Konstantinov, Dmitri; L\"onnblad, Leif; Monk, James; Pokorski, Witold; Przedzinski, Tomasz; Verbytskyi, Andrii  (2021). The HepMC3 event record library for Monte Carlo event generators. Comput. Phys. Commun., 260, 107310More Information

Aielli, Giulio; others  (2020). Expression of interest for the CODEX-b detector. Eur. Phys. J. C, 80 (12) , 1177More Information

Aaij, Roel; others  (2020). Search for $A'\to\mu^+\mu^-$ Decays. Phys. Rev. Lett., 124 (4) , 041801More Information

Ilten, Philip  (2021). CIMBA: fast Monte Carlo generation using cubic interpolation. Comput. Phys. Commun., 258, 107622More Information

Cid Vidal, Xabier; Ilten, Philip; Plews, Jonathan; Shuve, Brian; Soreq, Yotam  (2019). Discovering True Muonium at LHCb. Phys. Rev. D, 100 (5) , 053003More Information

Alimena, Juliette; others  (2020). Searching for long-lived particles beyond the Standard Model at the Large Hadron Collider. J. Phys. G, 47 (9) , 090501More Information

Cepeda, M.; others  (2019). Report from Working Group 2: Higgs Physics at the HL-LHC and HE-LHC. CERN Yellow Rep. Monogr., 7, 221More Information

Aaij, Roel; others  (2019). Design and performance of the LHCb trigger and full real-time reconstruction in Run 2 of the LHC. JINST, 14 (04) , P04013More Information

Cid Vidal, Xabier; others  (2019). Report from Working Group 3: Beyond the Standard Model physics at the HL-LHC and HE-LHC. CERN Yellow Rep. Monogr., 7, 585More Information

Cerri, A.; others  (2019). Report from Working Group 4: Opportunities in Flavour Physics at the HL-LHC and HE-LHC. CERN Yellow Rep. Monogr., 7, 867More Information

Aaij, Roel; others  (2018). Physics case for an LHCb Upgrade II - Opportunities in flavour physics, and beyond, in the HL-LHC era.

Alexander, M.; others  (2018). Mapping the material in the LHCb vertex locator using secondary hadronic interactions. JINST, 13 (06) , P06008More Information

Ilten, Philip; Soreq, Yotam; Williams, Mike; Xue, Wei  (2018). Serendipity in dark photon searches. JHEP, 06, 004More Information

Harland-Lang, Lucian; Ilten, Philip; Kretzschmar, Jan  (2018). Working Group 1: Structure Functions and Parton Densities. PoS, DIS2017, 021More Information

Aaij, Roel; others  (2018). Search for Dark Photons Produced in 13 TeV $pp$ Collisions. Phys. Rev. Lett., 120 (6) , 061801More Information

Battaglieri, Marco; others  (2017). US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report.

Ilten, Philip; Rodd, Nicholas L.; Thaler, Jesse; Williams, Mike  (2017). Disentangling Heavy Flavor at Colliders. Phys. Rev. D, 96 (5) , 054019More Information

Aaij, Roel; others  (2017). Study of J/\ensuremath\psi Production in Jets. Phys. Rev. Lett., 118 (19) , 192001More Information

Ilten, Philip; Williams, Mike; Yang, Yunjie  (2017). Event generator tuning using Bayesian optimization. JINST, 12 (04) , P04028More Information

Alexander, Jim; others  (2016). Dark Sectors 2016 Workshop: Community Report.

Ilten, Philip; Soreq, Yotam; Thaler, Jesse; Williams, Mike; Xue, Wei  (2016). Proposed Inclusive Dark Photon Search at LHCb. Phys. Rev. Lett., 116 (25) , 251803More Information

Boettcher, Tom; Ilten, Philip; Williams, Mike  (2016). Direct probe of the intrinsic charm content of the proton. Phys. Rev. D, 93 (7) , 074008More Information

Ilten, Philip; Thaler, Jesse; Williams, Mike; Xue, Wei  (2015). Dark photons from charm mesons at LHCb. Phys. Rev. D, 92 (11) , 115017More Information

Aaij, Roel; others  (2015). First observation of top quark production in the forward region. Phys. Rev. Lett., 115 (11) , 112001More Information

Aaij, Roel; others  (2015). Measurement of the forward $Z$ boson production cross-section in $pp$ collisions at $\sqrts=7$ TeV. JHEP, 08, 039More Information

Aaij, Roel; others  (2015). Identification of beauty and charm quark jets at LHCb. JINST, 10 (06) , P06013More Information

Ilten, Philip  (2015). Pythia 8: Simulating Tau-Lepton Decays. Nucl. Part. Phys. Proc., 260, 56More Information

Aaij, Roel; others  (2015). Study of $W$ boson production in association with beauty and charm. Phys. Rev. D, 92 (5) , 052001More Information

Sj\"ostrand, Torbj\"orn; Ask, Stefan; Christiansen, Jesper R.; Corke, Richard; Desai, Nishita; Ilten, Philip; Mrenna, Stephen; Prestel, Stefan; Rasmussen, Christine O.; Skands, Peter Z.  (2015). An introduction to PYTHIA 8.2. Comput. Phys. Commun., 191, 159More Information

Williams, M.; Benson, S.; Brodzicka, J.; Fitzpatrick, C.; Gligorov, V. V.; Ilten, P.; Vesterinen, M.  (2014). Trigger selections for the LHCb upgrade.

Aaij, R; others  (2013). Limits on neutral Higgs boson production in the forward region in $pp$ collisions at $\sqrts = 7$ TeV. JHEP, 05, 132More Information

Aaij, R; others  (2013). A study of the $Z$ production cross-section in $pp$ collisions at $\sqrts = 7$ TeV using tau final states. JHEP, 01, 111More Information

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iltenpj@uc.edu