Dr J J Kempster

Position:Research Fellow
Room:West 322


Jacob Kempster is a postdoctoral research fellow on the ATLAS experiment in the Birmingham Particle Physics Group.


Jacob completed his PhD in Particle Physics at Royal Holloway, University on London, entitled Measurements of charge and CP asymmetries in b-hadron decays using top-quark events collected by the ATLAS detector in pp collisions at s = 8 TeV (2017).


Jacob is a Convener for the ATLAS Top+X Physics Analysis Subgroup, he develops and drives the research program for 20 teams comprising of 150 scientists.
His area of expertise is in the study of the top quark as a window to new physics. He completed the first ever study of CP violation in the heavy-flavour sector using top quarks from LHC data as a production mechanism, and utilising the tagging of semileptonic decays of B-hadrons via the identification of resultant soft muons (Link to paper). He was also a leading author for a measurement top-quark pair spin correlations and led the interpretation of the result as a search for Supersymmetric stop-quark production (Link to paper).
He actively contributes to measurements of top-quark charge asymmetry, as well as searches for new physics and precision measurements of rare processes in Top+X decay channels.
Jacob has experience in the development of trigger simulations, having studied the effect of the Insertable B-Layer on the ATLAS Inner Detector track resolutiaon, prior to its installation. He is presently in charge of developing bitwise-accurate simulations of new ATLAS Level-1 Calorimeter Triggers, as part of Run-3 upgrades and beyond.


Jacob has worked as a one-to-one tutor for undergraduate students, and has previously run a Year 3 undergraduate 'Group Studies' course designed to provide real collaborative experience to students working on open questions for the design and simulation of future particle physics experiments. He is presently an active tutor running a Year 3 undergraduate 'Numerical Modelling' course, in which students are tasked with solving varying real-world problems from satellite orbits, the spread of forest fires, and games of billiards. Through solving these issues using Python programming, the students learn about the limitations inherent in both numerical methods and in computational precision.


Jacob has been involved in student outreach projects on university sites and in schools, and presented during the Royal Society Summer Science Exhibition in London on the discovery of the Higgs boson. He was also an official underground guide for public and VIP visits to the ATLAS experimental cavern for 2 years during his long-term attachment at CERN, Switzerland.