Dr. Greig Cowan

Position:
STFC Fellow
Research Theme:
Particle and Nuclear Physics
Research Group:
Particle Physics Experiment
Institution:
Edinburgh
g.cowan@ed.ac.uk
Website:
http://www2.ph.ed.ac.uk/~gcowan1
Telephone number:
+44 (0)131 651 7037
School of Physics and Astronomy, James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, United Kingdom

Research interests

• LHCb

The LHCb experiment at CERN is searching for new physics through precision measurements of the properties of heavy quarks.

Quarks are the fundamental building blocks of the protons and neutrons which make up atomic nuclei. The study of heavy quarks has a long and illustrious history, and led to many important discoveries and the award of the 2008 Nobel prize in physics to the theorists who first wrote down the mathematics of CP-violation in the SM. The LHCb experiment is continuing this legacy by studying heavy quarks in unprecedented detail due to the huge size of the event samples that it can record, process and analyse at the CERN LHC.

Other experiments at the LHC have yet to find any direct evidence of new physics beyond the SM: they are currently pushing the energy boundaries of their searches into the multi-TeV scale. LHCb can indirectly probe to much higher energies via the presence of non-SM particles in the quantum virtual loops of the heavy-quark decay processes.

My research aims to perform the precise measurements of CP-violating and heavy-quark properties. To do this requires us to have a deep understanding of the reconstruction and selection of many different processes which occur in the LHC, requiring the use of clever algorithms and modern computing technology to help us dig out signals from the large background noise. This technology will be used in the next generation of grid/cloud computing, with all the potential for innovation that it brings. We have to understand the subtle effects which our experimental apparatus can have on the measurements, a task which only becomes more difficult as the size of the data sample grows.

• Hyper-Kamiokande

The Hyper-Kamiokande (Hyper-K) experiment is the next generation flagship facility for the study of neutrino oscillations, nucleon decays, and astrophysical neutrinos.

Hyper-K is a third generation underground water Cherenkov detector situated in Kamioka, Japan. It consists of a 1 million tonne water target, which is about 20 times larger than that of the existing Super-Kamiokande (Super-K) detector. It will serve as the far detector for a long baseline neutrino oscillation experiment planned for the upgraded J-PARC proton synchrotron beam. With a total exposure of 7.50 MW x 107s to the 2.5degree off-axis neutrino beam, Hyper-K aims to make a measurement of the CP (charge-parity) violating phase of the neutrino mixing matrix, δCP, and to determine the neutrino mass hierarchy through the study of atmospheric neutrinos. It is expected that the CP phase δCP can be determined to better than 19degrees for all possible values of δCP and CP violation can be established with a statistical significance of 3(5)σ for 76(58)% of all possible values of δCP. Hyper-K will also serve as a detector capable of observing proton decays, atmospheric neutrinos, and neutrinos from astronomical origins enabling measurements that far exceed the current world best measurements.

We are currently performing R&D studies for the design of the proposed TITUS intermediate detector of Hyper-K. In addition we are characteristing new hybrid photo-detectors that are candidates for use in TITUS and Hyper-K.

Teaching

• Teaching assistant/lecturer for the Junior Honours "Numerical Methods" course.
• Teaching assistant for the Junior Honours "Research Methods" course.
• Teaching assistant for the Junior Honours "Data acquisition and handling" course.

Research outputs

1. Observation of the decay $\overline{B_s^0} \rightarrow χ_{c2} K^+ K^-$ in the $\varphi$ mass region DOI
LHCB Collaboration, L. Carson, P. E. L. Clarke, G. A. Cowan, D. C. Craik, S. Eisenhardt, E. Gabriel, S. Gambetta, K. Gizdov, F. Muheim et al., Journal of High Energy Physics (2018)
2. Measurement of the $\Upsilon$ polarizations in $pp$ collisions at $\sqrt{s}$=7 and 8TeV DOI
Peter Clarke, Greig Cowan, Stephan Eisenhardt, Franz Muheim, Matthew Needham, Stephen Playfer and LHCb Collaboration, Journal of High Energy Physics, 1712, p. 110 (2017)
3. Measurement of the shape of the $\Lambda_b^0\to\Lambda_c^+ \mu^- \overline{\nu}_{\mu}$ differential decay rate DOI
Peter Clarke, Greig Cowan, Stephan Eisenhardt, Franz Muheim, Matthew Needham, Stephen Playfer and LHCb Collaboration, Physical Review, D96, 11 , p. 112005 (2017)
4. Bose-Einstein correlations of same-sign charged pions in the forward region in $pp$ collisions at $\sqrt{s}$ = 7 TeV DOI
P E L Clarke, G A Cowan, S Eisenhardt, F Muheim, M Needham, S Playfer and LHCb Collaboration, Journal of High Energy Physics, 1712, p. 025 (2017)
5. Measurement of the $B^{\pm}$ production cross-section in pp collisions at $\sqrt{s} =$ 7 and 13 TeV DOI
Peter Clarke, Greig Cowan, Stephan Eisenhardt, Franz Muheim, Matthew Needham, Stephen Playfer and LHCb Collaboration, Journal of High Energy Physics, 1712, p. 026 (2017)
6. First Observation of the Rare Purely Baryonic Decay $B^0\to p\bar p$ DOI
Peter Clarke, Greig Cowan, Stephan Eisenhardt, Franz Muheim, Matthew Needham, Stephen Playfer and LHCb Collaboration, Physical Review Letters, 119, 23 , p. 232001 (2017)
7. Updated search for long-lived particles decaying to jet pairs DOI
Peter Clarke, Greig Cowan, Stephan Eisenhardt, Franz Muheim, Matthew Needham, Stephen Playfer and LHCb Collaboration, European Physical Journal C: Particles and Fields, C77, 12 , p. 812 (2017)
8. χc1 and χc2 Resonance Parameters with the Decays χc1,c2→J/ψμ+μ− DOI
Peter Clarke, Greig Cowan, Stephan Eisenhardt, Franz Muheim, Matthew Needham, Stephen Playfer and LHCb Collaboration, Physical Review Letters, 119, 22 (2017)
9. Measurement of $CP$ violation in $B^0\rightarrow J/\psi K^0_\mathrm{S}$ and $B^0\rightarrow\psi(2S) K^0_\mathrm{S}$ decays DOI
Peter Clarke, Greig Cowan, Stephan Eisenhardt, Franz Muheim, Matthew Needham, Stephen Playfer and LHCb Collaboration, Journal of High Energy Physics, 1711, p. 170 (2017)
10. Measurement of $CP$ observables in $B^{\pm} \rightarrow D K^{*\pm}$ decays using two- and four-body $D$ final states DOI
Peter Clarke, Greig Cowan, Stephan Eisenhardt, Franz Muheim, Matthew Needham, Stephen Playfer and LHCb Collaboration, Journal of High Energy Physics, 1711, p. 156 (2017)
Last updated: 19 Feb 2018 at 21:11