# Prof. Stephen Playfer

Position:
Personal Chair
Research Theme:
Particle and Nuclear Physics
Research Group:
Particle Physics Experiment
Institution:
Edinburgh
s.m.playfer@ed.ac.uk
Telephone number:
+44 (0)131 650 5275
School of Physics and Astronomy, James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, United Kingdom

## Research interests

I am an experimental particle physicist with a particular interest in the mysteries associated with the existence of three flavours of quarks and leptons. Their different masses and couplings (the CKM matrix for quarks, and the PMNS matrix for neutrinos), are free parameters in the Standard Model which have to be determined experimentally. The existence of three flavours leads to matter-antimatter asymmetries known as CP violation. Since we live in a matter-dominated universe the mechanisms for CP violation are a fundamental question, and the current Standard Model of particle physics does not produce enough baryon asymmetry in the universe by many orders of magnitude.

I seek to address these questions by studying rare decays of heavy flavours (b quarks, c quarks and tau leptons), and by measuring CP violation in the decays of neutral B mesons. From 2000-2010 I led a group working within the BaBar collaboration at SLAC, where we studied rare radiative and electroweak B decays. Currently I am a member of the LHCb experiment at CERN, studying CP violation in rare hadronic decays of B mesons.

## Teaching

I have taught undergraduate physics at all levels, including courses on waves, electromagnetism, dynamics & relativity and particle physics. Currently I am teaching second year waves (as part of the Classical & Modern Physics course), and supervising the third year experimental laboratory.

In 2011/2012 I was the convenor of a working group (Forward Look Implementation), that completely redesigned the core courses in our main degree programmes. From 2012 I have been the Convenor of the Board of Examiners in Physics. Also since 2012 I have been an External Examiner for Birmingham University.

## Research outputs

1. Measurement of Z -> tau(+)tau(-) production in proton-proton collisions at root s=8 TeV DOI
LHCb collaboration, M. Alexander, S. Ali, J. E. Andrews, S. Benson, R. Calabrese, L. Carson, M. G. Chapman, C. Chen, S. Chen et al., Journal of High Energy Physics, 9 (2018)
2. 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)
3. 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)
4. 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)
5. 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)
6. 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)
7. 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)
8. 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)
9. 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)
10. 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)
Last updated: 19 Feb 2018 at 21:11