Dr Helen O'Keeffe


Research Overview

I joined the department in September 2013 as a lecturer in experimental neutrino physics, following post-doctoral positions at the University of Oxford and Queen’s University, Ontario, Canada. My research focuses on particle physics, in particular measuring properties of the neutrino. I am currently involved with the Tokai to Kamioka (T2K), Hyper-Kamiokande and SNO+ experiments.

The T2K experiment searches for the appearance of electron neutrinos in a muon neutrino beam. In the experiment, a beam of muon neutrinos is produced at J-PARC in Tokai-mura, Ibaraki, Japan, and its composition is measured 280 m downstream of the production point. The beam is fired 295 km through the Earth to the Super Kamiokande detector, where its properties are also measured. Comparison of the beam measurements at each detector indicates that following their 295 km journey; some of the muon neutrinos have changed type (oscillated) into electron or tau neutrinos. Detailed analysis of the data allows (some of) the parameters associated with the oscillations to be determined. Within T2K I am a convener of the neutral pion (pi0) analysis group. The group uses data from the near detector to measure pi0 production cross sections. I also am actively involved with the operation and maintenance of the near detector Data Acquisition (DAQ) and electronic systems and I occasionally coordinate operations at the near detector complex.

Hyper-Kamiokande is a proposed mega tonne water Cherenkov detector that will act as the far detector for a future “next-generation” long baseline neutrino experiment using the upgraded J-PARC beam. It will investigate CP violation in the neutrino sector by observation of oscillations of neutrino and antineutrino beams produced by J-PARC. Observation of CP violation in the neutrino sector could help to explain why the universe is made from “matter”, rather than the expected equal amounts of matter and antimatter. The Hyper-Kamiokande experiment will study proton decays, atmospheric neutrinos, and neutrinos from astrophysical origins. Within the Hyper-Kamiokande collaboration, I am deputy work package manager for the UK DAQ effort, with responsibility for physics simulations relating to trigger design.

SNO+ is a multi-purpose low-energy neutrino experiment, currently under construction in the SNOLAB facility, near Sudbury, Ontario, Canada. Located 2 km underground in an active nickel mine, the detector will consist of around 780 tonnes of linear alkylbenzene (LAB) liquid scintillator, loaded with tellurium. The scintillator mixture will be held in a 12 m diameter acrylic sphere, surrounded by 7000 tonnes of ultra pure water shielding and approximately 9500 photomultiplier tubes. The acrylic vessel and PMT array were inherited from the successful Sudbury Neutrino Observatory (SNO) experiment. The primary goals of the SNO+ physics programme include measurements of low energy components of the solar neutrino flux and a search for neutrinoless double beta decay using tellurium. Observation of neutrinoless double beta decay would provide information about the absolute mass of the neutrino and also reveal whether the neutrino is its own antiparticle. I am principle investigator for the Lancaster SNO+ group and member of the SNO+ scientific board. I am co-leader of the backgrounds working group, whose role it is to assess, constrain and reduce background levels in all parts of the detector.

In addition to my research, I organise the annual “Particle Physics Masterclass” at Lancaster, attended by approximately 180 local sixth form students.

Selected Publications Show all 57 publications

Neutrino oscillation physics potential of the T2K experiment
T2K Collaboration 1/04/2015 In: Progress of Theoretical and Experimental Physics. 2015, 4, 36 p.
Journal article

Search for short baseline $ν_e$ disappearance with the T2K near detector
T2K Collaboration 16/03/2015 In: Physical Review D. 91, 5, 8 p.
Journal article

Measurements of neutrino oscillation in appearance and disappearance channels by the T2K experiment with 6.6E20 protons on target
T2K Collaboration 29/04/2015 In: Physical Review D. 91, 7, 50 p.
Journal article

T2K neutrino flux prediction
T2K Collaboration, Finch, A., Kormos, L., Bertram, I., Ratoff, P., Bentham, S., Reeves, M., Grant, N., Southwell, L., O'Keeffe, H., Dealtry, T.J. 2/01/2013 In: Physical Review D. 87, 1, 34 p.
Journal article

Measurement of neutrino oscillation parameters from muon neutrino disappearance with an off-axis beam
T2K Collaboration 19/11/2013 In: Physical Review Letters. 111, 21, 7 p.
Journal article

The electromagnetic calorimeter for the T2K near detector ND280
Kormos, L., Bertram, I., Ratoff, P., Bentham, S., Grant, N., Reeves, M., Finch, A., Davies, G., O'Keeffe, H., Hatzikoutelis, A., Maryon, T., Mercer, I., Reeves, M. 17/10/2013 In: Journal of Instrumentation. 8, 10, 42 p.
Journal article

Low-energy-threshold analysis of the Phase I and Phase II data sets of the Sudbury Neutrino Observatory
Aharmim, B., Ahmed, S.N., Anthony, A.E., Barros, N., Beier, E.W., Bellerive, A., Beltran, B., Bergevin, M., Biller, S.D., Boudjemline, K., Boulay, M.G., Burritt, T.H., Cai, B., Chan, Y.D., Chauhan, D., Chen, M., Cleveland, B.T., Cox, G.A., Dai, X., Deng, H., Detwiler, J., DiMarco, M., Doe, P.J., Doucas, G., Drouin, P., Duba, C.A., Duncan, F.A., Dunford, M., Earle, E.D., Elliott, S.R., Evans, H.C., Ewan, G.T., Farine, J., Fergani, H., Fleurot, F., Ford, R.J., Formaggio, J.A., Gagnon, N., Goon, J.T., Graham, K., Guillian, E., Habib, S., Hahn, R.L., Hallin, A.L., Hallman, E.D., Harvey, P.J., Hazama, R., Heintzelman, W.J., Heise, J., Helmer, R.L., Hime, A., Howard, C., Howe, M.A., Huang, M., Jamieson, B., Jelley, N.A., Keeter, K.J., Klein, J.R., Kormos, L.L., Kos, M., Kraus, C., Krauss, C.B., Kutter, T., Kyba, C.C.M., Law, J., Lawson, I.T., Lesko, K.T., Leslie, J.R., Levine, I., Loach, J.C., MacLellan, R., Majerus, S., Mak, H.B., Maneira, J., Martin, R., McCauley, N., McDonald, A.B., McGee 05/2010 In: Physical Review C. 81, 5, p. -. 49 p.
Journal article

Searches for high-frequency variations in the 8B solar neutrino flux at the Sudbury Neutrino Observatory
Kormos, L., O'Keeffe, H. 02/2010 In: The Astrophysical Journal. 710, 1, p. 540-548. 9 p.
Journal article

The calibration of the Sudbury Neutrino Observatory using uniformly distributed radioactive sources
Boudjemline, K., Cai, B., Cleveland, B.T., Evans, H.C., Ewan, G.T., Farine, J., Ford, R.J., Guillian, E., Hallin, A.L., Hallman, E.D., Howard, C.V., Jagam, P., Jelley, N.A., Keeter, K.J., Klein, J.R., Kraus, C., Krauss, C.B., Lange, R., Lawson, I.T., Loach, J.C., McDonald, A.B., Mcgregor, G., Noble, A.J., O'Keeffe, H., Peeters, S.J.M., Poon, A.W.P., Reitzner, S.D., Rielage, K., Robertson, R.G.H., Rusu, V.l., Seibert, S.R., Skensved, P., Thomson, M.J. 1/08/2010 In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 620, 2-3, p. 171-181. 11 p.
Journal article