The Experimental Particle Physics group at Lancaster University is looking for a research associate to join the experimental kaon physics group from 1st April 2025 to work on the KOTO II experiment, for a duration of 3 years. You would work with Dr Karim Massri. The position is funded by the Royal Society via the International Science Partnerships Fund (ISPF). The ISPF International Collaboration Awards provide funding to enable outstanding emerging research leaders in the UK to develop research collaborations with international partners (in the case of the award, from Japan). The KOTO II experiment at J-PARC is a next-generation experiment planned to achieve the first observation of the ultra-rare K L → π 0 νν decay and measure its branching ratio with a O(30%) precision, by collecting O(30) signal candidates. The project "New physics discovery through ultra-rare measurements with neutral kaons" aims to consolidate the analysis strategy for the K L → π 0 νν analysis at the KOTO II experiment and explore the feasibility of the measurements of the ultra-rare K L → π 0 ℓ ℓ − decays, with a compatible detector setup for the two measurements. Besides making significant contributions to the KOTO II simulation, you will investigate the feasibility of the K L →π 0 ℓ ℓ − measurement at the KOTO II experiment. In particular, they will develop a tracking/PID strategy for the lepton pair, evaluate signal/background and optimize the detector configuration for the K L →π 0 ℓ ℓ − measurement. Lancaster University is consistently ranked in the top 10 in the UK university league tables. It is located on a beautiful campus in the North-West of England close to the Lake District National Park. The Department of Physics is committed to family-friendly and flexible working policies on an individual basis, as well as the Athena SWAN Charter, which recognises and celebrates good employment practice undertaken to address gender equality in higher education and research. We are also strongly committed to fostering diversity within our community as a source of excellence, cultural enrichment, and social strength. We welcome those who would contribute to the further diversification of our department. Informal enquiries can be made to Dr Karim Massri ( karim.massricern.ch ).