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Department of Physics

The Cavendish Laboratory


William (Bill) Balunas received his Bachelor of Science degree in 2013 from Carnegie Mellon University before moving to the University of Pennsylvania for his graduate studies. He was awarded a Ph.D. in 2018 for his work on invisible decays of the Higgs boson, which included two years at CERN. He then went to Oxford as a postdoctoral researcher, where he became a Junior Research Fellow at Brasenose College and a Stipendiary Lecturer at St Hilda's College. In 2021, he came to Cambridge, where he currently holds the Walter Scott Fellowship in Physics at Trinity Hall.


My interests lie in fundamental particle physics, particularly on the experimental side. I am a member of the ATLAS Collaboration, which operates one of the major experiments at the Large Hadron Collider. My work focuses on using the Higgs boson as a tool to probe unexplored areas, inlcuding searches for physics beyond the Standard Model. Specific topics have included invisible decays of the Higgs boson, other searches for dark matter, measuring the Higgs self-interaction, and Higgs boson pair production as a means to seek out undiscovered particles. On the technical side, my expertise includes event reconstruction & data analysis software, reconstruction of hadronic showers and invisible particles, and Monte Carlo modelling of particle interactions.


Key publications: 

In experimental particle physics, all qualified members of an experiment are listed as authors on all publications it produces. This means my full publication list is currently over 700 items long. Below is a selection of the papers I've had the most active roles in producing recently. The complete list can be found at Inspire.

W. Balunas, D. Cavalli, T.J. Khoo, et al., A flexible and efficient approach to missing transverse momentum reconstruction. Comput. Softw. Big Sci. 8, 2 (2024).

ATLAS Collaboration, Anomaly detection search for new resonances decaying into a Higgs boson and a generic new particle X in hadronic final states using√s = 13 TeV pp collisions with the ATLAS detector. Phys. Rev. D 108 (2023) 052009.

ATLAS Collaboration, Search for nonresonant pair production of Higgs bosons in the bbbb final state using pp collisions at √s = 13 TeV with the ATLAS detector. Phys. Rev. D 108 (2023) 052003.

ATLAS Collaboration, Search for resonant pair production of Higgs bosons in the bbbb final state using pp collisions at √s = 13 TeV with the ATLAS detector. Phys. Rev. D 105 (2022) 092002.

ATLAS Collaboration, Search for dark matter produced in association with a single top quark in √s = 13 TeV pp collisions with the ATLAS detector. Eur. Phys. J. C 81 (2021) 860.

J. Amacker, W. Balunas, L. Beresford et al., Higgs self-coupling measurements using deep learning in the bbbb final state. JHEP 12 (2020) 115.

ATLAS Collaboration, Combination of Searches for Invisible Higgs Boson Decays with the ATLAS Experiment. Phys. Rev. Lett. 122 (2019) 23.

ATLAS Collaboration, Constraints on mediator-based dark matter and scalar dark energy models using √s = 13 TeV pp collisions at the LHC with the ATLAS detector. JHEP 05 (2019) 142.

ATLAS Collaboration, Search for invisible Higgs boson decays in vector boson fusion at √s = 13 TeV with the ATLAS detector. Phys. Lett. B 793 (2019) 499.

College Assistant Professor (Trinity Hall)
Fellow and Director of Studies at Trinity Hall

Contact Details

Email address: 
Rutherford 960A