# Dr. Christos Leonidopoulos

Position:
Research Theme:
Particle and Nuclear Physics
Research Group:
Particle Physics Experiment
Institution:
Edinburgh
christos.leonidopoulos@ed.ac.uk
Website:
http://www.ph.ed.ac.uk/people/christos-leonidopoulos
Telephone number:
+44(0)131 650 6769
School of Physics and Astronomy, James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, United Kingdom

## Research interests

Christos Leonidopoulos is a Chancellor's Fellow and a Reader at the University of Edinburgh.

He received his PhD from Princeton University in 2000, working on Bd mixing and CPT violation searches with the Belle experiment at KEK, Japan. In his thesis he carried out the first experimental test of CPT symmetry in the Bd system and produced the most precise mixing measurement in the world at the time [Int. J. Mod. Phys. A16S1A, 401-403 (2001) and Phys.Rev.Lett. 86 (2001) 3228, a paper with 153 citations].

He then worked on Bd and Bs mixing with the D0 experiment at Fermilab, Chicago as a Research Associate with Columbia University [Phys.Rev.Lett.97:241801 (2006), a paper with 51 citations and Phys.Rev.Lett. 97 (2006) 021802, a paper with 368 citations]. In parallel, he led the integration and commissioning of the Level-2 muon trigger [Nucl.Instrum.Meth. A565 (2006) 463-537].

He moved to Geneva, Switzerland in 2004 as Research Physics Staff with CERN where he worked on building the CMS experiment, and in particular on the design, implementation and commissioning of a novel triggering system known as the High Level Trigger [CERN/LHCC 2007-021, LHCC-G-134 (2007)J.Phys.G34:995-1579 (2007)JINST 0803:S08004 (2008) and JINST 5:T03005 (2010)]. He served as the Deputy Trigger Coordinator for the startup of the LHC and for four years.

In 2011 he received an LPC Fellowship by Fermilab during which he implemented with his team a program of generic searches for new heavy charged bosons, producing the most stringent exclusion limits in the world in several final states [Phys. Lett. B701, 160–179 (2011): a paper with 58 citations, JHEP 08 (2012) 023: a paper with 98 citations, Phys. Rev. Lett. 109, 141801 (2012): a paper with 45 citations, and JHEP 02 (2013) 036, a paper with 44 citations]. His involvement with CMS culminated with the discovery of the Higgs boson [Phys.Lett. B716 (2012) 30-61, a paper with 8,600+ citations].

He moved to Edinburgh in 2012 with a Chancellor's Fellowship and joined the ATLAS experiment. He worked on the measurement of the Higgs boson properties [Phys. Rev. D 91, 012006 (2015): a paper with 259 citations; Phys. Rev. D. 90, 052004 (2014): a paper with 430 citations, and Eur. Phys. J. C (2015) 75:335: a paper with 118 citations].

With the beginning of Run-2, he launched a new programme of searches for exotic particles, and in particular for diboson resonances, Dark Matter mediators, and right-handed W bosons and heavy neutrinos [JHEP 09(2016)173:  a paper with 81 citations, Phys. Lett. B 777 (2017) 91: a paper with 32 citations, JHEP 03 (2018) 009: a paper with 38 citations, JHEP 04(2016)155: a paper with 22 citations, arXiv:1801.08769/Phys. Lett. B: a paper with 21 citations, and arXiv:1809.11105/JHEP ].

He served as the Trigger Menu coordinator for the ATLAS experiment for two years (2016-8). He currently serves as the Online software and computing (WG10) Convener for the FCC-ee/TLEP concept study [JHEP01(2014)164: a paper with 451 citations].

He designed (and has been running every year since 2014) a MOOC on the discovery of the Higgs boson, a course with thousands online subscribers.

His general research interests lie in the Electroweak Symmetry-Breaking mechanism, in Exotic physics searches at the LHC, and in triggers. In the next years, together with his research team, he will be focussing on searches for new exotic particles and upgrades of the High-Level Trigger for the ATLAS experiment at the LHC, and the design of future colliders.

## Teaching

Higgs Massive Open Online Course (MOOC)

• Overall coordination and design of the course (with Prof. Luigi Del Debbio)
• Development of lecture discussing the experimental aspects of the discovery of the Higgs boson.

Run dates:

• Every year since 2014
• Next launch date: February 2019

https://www.futurelearn.com/courses/higgs

Programming, Data Analysis and Machine Learning (PGPH11102)

• Post-graduate course covering core skills related to data analysis and statistical interpretation: maximum likelihood fits, systematic effects, hypothesis testing, advanced techniques such as multivariate methods and machine learning, and simulation of experimental data.
• Data analysis techniques are applied to data collected by current experiments.
• 2018-today

Collider Physics

• Post-graduate course with the Scottish Universities Physics Alliance (Spring); Emphasis given on recent experimental resuls & papers
• 2013 - today

Relativity, Nuclear and Particle Physics (PHYS10096)

• "Particle Physics" component with lectures & tutorials (Autumn); Emphasis given on recent experimental resuls & papers
• 2014 - today

## Research outputs

1. Femtoscopy with identified charged pions in proton-lead collisions at √sNN=5.02 TeV with ATLAS DOI
Philip James Clark, Christos Leonidopoulos, Victoria Jane Martin, Corrinne Mills and Atlas Collaboration, Physical Review C, 96, 6 (2017)
2. Search for squarks and gluinos in events with an isolated lepton, jets, and missing transverse momentum at √s=13  TeV with the ATLAS detector DOI
Philip James Clark, Christos Leonidopoulos, Victoria Jane Martin, Corrinne Mills and Atlas Collaboration, Physical Review D, Particles and fields, 96, 11 (2017)
3. Search for direct top squark pair production in final states with two leptons in $\sqrt{s} = 13$ TeV $pp$ collisions with the ATLAS detector DOI
Philip James Clark, Christos Leonidopoulos, Victoria Jane Martin, Corrinne Mills and Atlas Collaboration, European Physical Journal C: Particles and Fields, C77, 12 , p. 898 (2017)
4. Determination of the strong coupling constant $\alpha _\mathrm {s}$ from transverse energy–energy correlations in multijet events at $\sqrt{s} = 8~\hbox {TeV}$ using the ATLAS detector DOI
Philip James Clark, Christos Leonidopoulos, Victoria Jane Martin, Corrinne Mills and Atlas Collaboration, European Physical Journal C: Particles and Fields, C77, 12 , p. 872 (2017)
5. Search for a scalar partner of the top quark in the jets plus missing transverse momentum final state at s√=13s=13 TeV with the ATLAS detector DOI
Philip James Clark, Christos Leonidopoulos, Victoria Jane Martin, Corrinne Mills and Atlas Collaboration, Journal of High Energy Physics, 1712 (2017)
6. Measurement of the Drell-Yan triple-differential cross section in pp collisions at $\sqrt{s}=8$ TeV DOI
Philip James Clark, Christos Leonidopoulos, Victoria Jane Martin, Corrinne Mills and Atlas Collaboration, Journal of High Energy Physics, 1712, p. 059 (2017)
7. Measurement of the cross-section for electroweak production of dijets in association with a Z boson in pp collisions at $\sqrt {s}$ = 13 TeV with the ATLAS detector DOI
Philip James Clark, Christos Leonidopoulos, Victoria Jane Martin, Corrinne Mills and Atlas Collaboration, Physics Letters B, B775, p. 206-228 (2017)
8. Search for new phenomena in high-mass diphoton final states using 37 fb$^{-1}$ of proton--proton collisions collected at $\sqrt{s}=13$ TeV with the ATLAS detector DOI
Philip James Clark, Christos Leonidopoulos, Victoria Jane Martin, Corrinne Mills and Atlas Collaboration, Physics Letters B, B775, p. 105-125 (2017)
9. Search for dark matter in association with a Higgs boson decaying to two photons at $\sqrt{s}$ = 13 TeV with the ATLAS detector DOI
Philip James Clark, Christos Leonidopoulos, Victoria Jane Martin, Corrinne Mills and Atlas Collaboration, Physical Review, D96, 11 , p. 112004 (2017)
10. Study of the material of the ATLAS inner detector for Run 2 of the LHC DOI
Philip James Clark, Christos Leonidopoulos, Victoria Jane Martin, Corrinne Mills and Atlas Collaboration, Journal of Instrumentation, 12, 12 (2017)
Last updated: 06 Mar 2019 at 10:01