[School of Natural Sciences PhD Scholarships] Probing the Standard Model vacuum: AI-assisted searches for QCD instantons and electroweak sphalerons at ATLAS

About the project

About the Project This PhD project will develop new searches for QCD instantons and electroweak sphalerons at the ATLAS experiment. These processes arise from the non-trivial vacuum structure of the Standard Model and are connected to fundamental questions in particle physics, including the strong CP problem and the origin of the matter-antimatter asymmetry of the Universe. The student will initially study the sensitivity of ATLAS to both processes before developing the most promising search into a full analysis of the Run-3 dataset. QCD instantons could produce distinctive high-multiplicity multijet signatures at relatively low partonic centre-of-mass energies. The project will exploit a high-statistics Run-3 hadronic dataset enabled by novel real-time analysis developments led by the Manchester group, opening sensitivity to signatures that were previously difficult to record. Electroweak sphaleron processes would instead produce spectacular signatures at much higher energies, with multiple quark jets, leptons and electroweak bosons. The student will investigate advanced techniques including quark flavour identification, jet substructure and machine learning to maximise sensitivity to these signatures. In parallel, the student will develop and validate autonomous AI workflows for jet calibration and detector performance. These systems have the potential to automate complex calibration tasks while maintaining scientific transparency, reliability and reproducibility. Developing autonomous workflows could help address the increasing computational and person-power demands of the High-Luminosity LHC programme. The successful candidate will join the Manchester ATLAS group and work closely with researchers in Manchester and at CERN. The group has major expertise in trigger and data acquisition, jet and combined detector performance, physics analysis and machine learning. The student will be embedded within the relevant international ATLAS analysis and performance groups and supported by the supervisors and postdoctoral researchers in Manchester. They will gain broad training in collider physics, statistical data analysis, machine learning and agentic AI while contributing to the scientific programme of the world's largest particle physics experiment. This project is expected to start in September 2027. Before you apply: We strongly recommend that you contact the supervisors for this project before you apply. How to apply: To be considered for this project you must complete a formal application through our online application portal. If you already have an applicant account this link will directly open an application for PhD School of Natural Sciences Scholarships . If you don’t already have an applicant account, please follow the instructions here . When applying, please specify the full title and supervisor/s of the project, details of your previous study, and names and contact details of two referees. You must also upload a Supporting Statement describing your motivation to apply to the project, your CV and transcripts of awarded and in-progress university qualifications . Please note late or incomplete applications will not be considered. Equality, diversity and inclusion are fundamental to the success of The University of Manchester and central to all our activities. A diverse research community strengthens creativity, productivity and quality, while increasing the societal and economic impact of our work. We welcome applicants from all career paths, backgrounds and sections of the community, regardless of age, disability, ethnicity, gender, gender expression, sexual orientation or transgender status. We welcome applications from candidates returning to study after a career break or experience in other roles. Flexible study arrangements may be available, including part-time study at 50%, 60% or 80%, subject to the requirements of the project and funder. Eligibility : The standard academic entry requirement for this PhD is an upper second-class (2:1) honours degree in Physics (or international equivalent) OR any upper-second class (2:1) honours degree and a Master’s degree at merit in Physics (or international equivalent). This project will remain open until filled. If your application is submitted by 1 st November 2026, you can expect a decision by 18 th December 2026. If your application is submitted by 15 th January 2027, you can expect a decision by 30 th March 2027. Self or externally funded students can also be considered for this project. FSESoNS

Research areas