Georgios Konstantinos Krintiras
PhD student. Funding: FSR,UCL.
Member since February 2015
Centre for Cosmology, Particle Physics and Phenomenology - CP3
Université catholique de Louvain
2, Chemin du Cyclotron - Box L7.01.05
B-1348 Louvain-la-Neuve
+32 10 47 3217
First measurement of the t-channel single top-quark cross section with CMS at √s = 13 TeV
Measurement of the associated Higgs production with single top-quarks in the t-channel with CMS at √s = 13 TeV
Top quark pair production cross section measurements with CMS
Measurement of the associated Higgs production with top quarks in CMS at √s = 13 TeV
Study of top production in complementary phase space regions and impact on PDFs in CMS
Observation of top quark production in proton-nucleus collisions
Poster Presentations
Constraining QCD multijet background in the t-channel single top-quark production at √s = 13 TeV
Measurement of the top quark pair production cross section using dilepton events at √s = 5.02 TeV
Luminosity calibration at √s = 5.02 TeV
Luminosity calibration at √s = 5.02 TeV
Measurement of the top quark pair production cross section and luminosity calibration at √s = 5.02 TeV
I am involved in the following research directions:

Fast Simulation of the CMS experiment

A framework for Fast Simulation of particle interactions in the CMS detector (FastSim) has been developed and implemented in the overall simulation, reconstruction and analysis framework of CMS. It produces data samples in the same format as the one used by the Geant4-based (henceforth Full) Simulation and Reconstruction chain; the output of the Fast Simulation of CMS can therefore be used in the analysis in the same way as data and Full Simulation samples. FastSim is used in several physics analyses in CMS, in particular those requiring a generation of many samples to scan an extended parameter space of the physics model (e.g. SUSY) or for the purpose of estimating systematic uncertainties. It is also used by several groups to design future sub-detectors for the Phase-II CMS upgrades.
Related activities at UCL include the integration with the Full Simulation in the simulation of the electronic read-out ("digitization") and of the pileup of events from other proton-proton collisions, both in-time and out-of-time; the performance monitoring; and the overall maintenance and upgrade of the tracking-related code. Matthias Komm is current L3 convener of Tracking in FastSim, and Andrea Giammanco has been main responsible of the FastSim project from 2011 to 2013.

Luminosity calibration of the CMS detector

We contribute to the offline absolute calibration of the luminometry system of the CMS detector, by analysing the dedicated "Van der Meer scan" data at different center-of-mass energies and collision types (p-p, p-Pb, Pb-Pb).

As a related task, we also contribute to the data-driven inference of the true amount of "pile-up" collisions.

External collaborators: CMS Luminosity Physics Object Group.

Single top studies at LHC

The electroweak production cross section of single top quarks is an important measurement for LHC, being a potential window on "new physics" effects.
Past achievements of this group include the very first measurement at 7 TeV (in t channel) with 2010 data, followed by the most precise inclusive cross section measurements of t-channel cross section at 7, 8 and 13 TeV, and the first differential measurements at 13 TeV; the most precise |Vtb| extraction from single top in the world; the first measurement of W-helicity fractions in a single-top topology; the first observation of the tW production mode; the first measurement of single-top polarization in t channel; stringent limits on anomalous tWb, tgu, tgc couplings.

External collaborators: CMS collaboration.

Testing the sign of the coupling of the new H(125) boson to top quarks with the CMS data

During 2012, the CMS and ATLAS collaborations independently reported unambiguous evidence of the existence of a new particle of mass around 125 GeV.
Several analyses are ongoing to challenge the hypothesis that the new particle is the SM Higgs. We focus on the search for its production in association with a single top quark. Due to an effect of quantum interference, this process is strongly suppressed in the Standard Model while it gets enhanced if its couplings to the top quark and to the W boson have opposite sign. An observation of this production mode would therefore be a convincing proof that this new particle does not belong to the Standard Model.
We published the first search for this process using 8 TeV data, and we expect to achieve sensitivity to anomalous values of the top Yukawa phase during the LHC Run-II.

External collaborators: CMS collaboration.

Top quarks in Heavy Ion collisions and other non-standard LHC datasets

The top quark, being the heaviest known elementary particle, is a powerful tool to test QCD.
The study of top quark pair production in Heavy Ion collisions at the LHC, making use of the dedicated Pb-Pb and p-Pb runs, will open a new road in the investigation of the Quark-Gluon Plasma.
This research project started with the first measurement of top-pair cross section in pp collisions at 5.02 GeV, taking advantage of a "reference run" in Nov.2015 (CMS-TOP-16-015 and CMS-TOP-16-023). This measurement, in addition to be useful as a reference for measurements in Pb-Pb and p-Pb collisions at the same center-of-mass energy per nucleon, also provides a significant broadening of the lever arm for global PDF fits making use of top-quark data. We are now working on the first observation of top quark production in p-Pb collisions (CMS-HIN-17-002).

External collaborators: David D'Enterria, Pedro Silva and Marta Verweij (CERN).

Show past projects.
Publications in CP3
Showing 5 publications over 10. Show all publications.
All my publications on Inspire


Observation of top quark production in proton-nucleus collisions
CMS Collaboration
[Abstract] [PDF] Submitted to Physics Review Letters
Refereed paper. 22nd September.
Inclusive tt cross section at sqrt(s)=5.02 TeV using final states with at least one charged lepton
CMS collaboration
[Full text] CMS Physics Analysis Note TOP-16-023, presented at the 25th edition of DIS, Birmingham
4th April.
CMS Luminosity Measurement for the 2016 Data Taking Period
CMS Collaboration
[Full text] Physics Analysis Note CMS-LUM-17-001
Public experimental note. 26th March.


CMS Luminosity Calibration for the pp Reference Run at sqrt(s) = 5.02 TeV
CMS Collaboration
[Full text] Physics Analysis Note CMS-LUM-16-001
Public experimental note. 1st December.
Cross section measurement of $t$-channel single top quark production in pp collisions at $sqrt s =$ 13 TeV
Sirunyan, Albert M and others
[Abstract] [PDF] [Journal] Most precise measurement of the single-top cross section at 13 TeV.
Refereed paper. Public experimental note. 4th October.
Further Material

[UCLouvain] - [SST] [IRMP] - [SC]
Contact : Jérôme de Favereau
Job opportunities PhD Position in Theoretical Particle Physics and Cosmology